Tesla plans to launch production of the Model S sedan sometime in early 2012.
A new video released by Silicon Valley start-up Tesla Motors suggests the maker is moving rapidly ahead with the development of its planned Model S sedan, and may very well make its ambitious target of going to market in 2012.
With a planned price tag under $50,000 – after federal and state rebates, where available – Tesla is hoping the Model S will prove naysayers wrong about the viability and flexibility of electric propulsion. Notably, to overcome so-called “range anxiety,” the ambitious automaker will offer three different battery packs: a base version delivering 160 miles under optimum conditions, one that pushes to 230 miles, and a third lithium-ion pack that will get as much as 300 miles per charge, about what a motorist might expect on a tank of gas with the typical automobile.
But company sources acknowledge that the larger batteries, especially the pack providing a 300-mile range, may be not only priced beyond what most motorists could afford – but that few, if any owners would be equipped to utilize its extended range without long layovers between drives.
A closer look at the aluminum-intensive underpinnings of the Tesla Model S sedan.
Tesla has just released a video of one of the first early, or alpha, prototypes of the Model S undergoing road testing. (Click Here to see it in action.) As with the maker’s original Tesla Roadster, the new sedan is shockingly quiet, even at highway speeds, one of the advantages of using electric propulsion.
In a statement describing the behavior of the Model S, Tesla’s Chief Dynamicist, Graham Sutherland, suggested, “The first Alpha is amazingly agile for a car of its size. It has great handling balance and poised ride with communicative steering. Just goes to show what combining a low center of gravity with a very stiff body structure can achieve.”
At the Detroit Auto Show, Tesla is showing off the guts of the Model S, hoping to underscore just how solid that aluminum intensive chassis and body structure will be. A close look reveals a double wishbone suspension, and a rear subframe designed to hold both the rear suspension and motor, as well as the driveline’s electronic control system.
“We assiduously pursued weight savings at absolutely no expense of safety,” asserted Peter Rollinson, the project’s engineering team leader, during an auto show news briefing.
A key design strategy makes use of the battery pack – which contains about 7,000 laptop computer-sized batteries – as a structural element mounted underneath the cabin. This has a “multiplier effect,” according to Robinson, improving rigidity and reducing noise and vibration, he claims.
Tesla has been counting on the rapid development of lithium-ion batteries, founder Elon Musk recently stressed in a conversation with TheDetroitBureau.com. That will pay off in a variety of ways, he asserted: including both improved energy density – which, for a motorist, translates into longer range – and lower costs.
Where analysts were basing forecasts on a price of about $1,000 per kilowatt hour for lithium-ion in 2009, Musk broadly hinted Tesla is counting on that dipping to $400 or less per kWh during the life of the Model S program. The savings could be enormous.
Consider the Nissan Leaf, which uses 24 kWh of LIon batteries to get an average 100 miles per charge. A pack that size would drop from $24,000 to $9,600 if it underwent the same reduction in price Tesla anticipates. (Nissan insiders are even more optimistic – a well-placed source telling TheDetroitBureau.com that the Japanese maker expects to get its batteries down to $300 a kilowatt-hour – or lower.)
But the bigger, longer-range Model S will need a lot more battery. According to Rollinson, Tesla expects the sedan to consumer 300 watt-hours a mile. A quick bit of math and that works out to 48 kWh for the smallest Model S battery. And that doesn’t take into consideration that lithium technology doesn’t like to be complete drained or 100% charged up. So, more likely, the new electric vehicle will start with a base battery pack in the range of 52 to 55 kWh.
For the 230-mile model, that would jump to somewhere near 75 kWh. And for the 300-mile range Model S, the pack would be an enormous 100 kWh or larger – at least three times the size of the Leaf battery.
Even if Tesla were to price the car based on the anticipated plunge in lithium-ion pricing, the battery pack for a 300-mile Model S would cost the company about $20,000 more than for the base vehicle. If the traditional option model holds, the California maker would charge nearly as much as the base car for the upgrade.
For the record, Rollinson and other Tesla officials are not commenting, but sources confirm TheDetroitBureau.com’s math. And there are even more problematic numbers.
There are plenty of folks willing and able to spend the money for the extra range. But price might not be the biggest obstacle. To make use of all that range one needs to get the batteries charged up. And that won’t be easy.
As early battery car customers are quickly learning, using household 110-volt current to charge an electric vehicle is an undesirable option. With Leaf, you’ll plug in as soon as you get home for work and barely be ready to go in time for the morning commute.
Opting for a Level II 220-volt charger will typically trim the charge time down by at least half. Depending on the amperage of the charging system, that can bring charging times down significantly. Ford’s 7.5-amp Level II charger for the upcoming Focus Electric is expected to trim times down to just 3.5 hours, about half the time required to recharge Leaf using its lower-amperage system.
The larger Model S, with its huge 300-mile battery, would, at best require about 14 hours to get back on the road – at best. A lower-amperage charger would keep the sedan tethered for a day or more. That is, unless an owner were ready to head out on only a partial charge. But, at that point, what would justify paying the huge price premium for the extra kilowatt-hours?
There is an alternative, said Rollinson, when pressed with this analysis, Level III chargers, which use 440 volts converted to DC current. For vehicles like the Leaf and Focus Electric, such systems could yield an 80% quick “fill-up” in as little as 20 to 30 minutes. Even then, the 300-mile Model S might need a couple hours.
And, of course, that assumes an owner were near a Level III charger. Currently, there’s only one publicly available, near Portland, Oregon, and it’s anyone’s guess how quickly more will be added to the emerging electric vehicle infrastructure.
Significantly, this would move Model S owners away from the strategy of being able to recharge overnight – at home – when electric rates are lowest.
The ability to drive from Detroit to Chicago, New York to Boston, and nearly from L.A. to San Francisco without recharging does have its appeal. But whether potential buyers will look past the drawbacks remains to be seen.
The 300 mile Model S battery is just under twice the size of the Roadster’s battery (the latter being 56kWh), so it’s going to take the same multiple of time to fill on an equivalent charging source.
I make that less than 6 hours for a full refill on a relatively cheap ($2k) Tesla HPC or the newer 75 Amp J1772 chargers which are starting to appear.
I’m really not sure where you got the 14 hours number from – you don’t need to be Eisenstein to work this stuff out…
D, I am going to put this to Tesla, if they will answer. But note that Ford’s planned 75 amp charger will take about 3.5 hours (on 220 volts) to recharge an estimated 24 kWH battery. And that math is basic, not calculus. Filling just 96 kWH will thus take about 14 hours. If, as likely, the Tesla 300-mile battery tops 100 kWH it will take even longer.
Paul A. Eisenstein
Publisher, TheDetroitBureau.com
Well, I’ve personally seen the 70 Amp HPC charge the Tesla Roadster in 3.5 hours.
If you do the math for the 75 A charger, 240 V * 75 A = 18 kW
If Tesla’s 300 mile battery is in the 100 kWh range, 10% would never be used for longevity reasons (like all EVs), so let’s say we need to charge 90 kWh.
90 kWh / 18 kW = 5 hours.
However, charging isn’t quite linear (more a slight S curve), so it will taper off near the top. For that you can add another hour.
It’s certainly nowhere near 14 hours.
So your HPC becomes an overnight charger for the 300 mile car. For road trips of over 300 miles, you need the DC fast charger that can recharge it in an hour. Fortunately hundreds of these are either installed or about to be installed in Japan, Europe and North America (see recent stories about CHAdeMO chargers being installed in the USA for example).
By the way, are you sure the Ford charger is 75 A? The car can only take 6.6kW, which means the charger need only be 30 A. I think that is the source of your confusion here.
D, A fair question and I will double-check the charging info on the Ford. Meanwhile, I think you’re being generous to Tesla. The Roadster’s pack is, if I recall, 53 kWh with pad. The Model S is consuming 300 watt-hours/mile, which means to do 300 miles will require a 100 kWh battery… BEFORE adding the pad. They are trying to squeeze out a little more efficiency, said their chief engineer (these numbers were delivered ON the record, though details of the 300-mile pack were not), so perhaps they could get it down to 96, but the difference will be modest. Yes, makers don’t want to use all the charge range because of the potential impact on battery life. They usually want a minimum 10% on either end, so that yields what? A 120 kWh battery? Maybe a wee bit less? Maybe even more?
If I accept your charging stats, and yes about the S-curve, we’ll still be at 8 hours, which is relatively acceptable, but I believe the 300-mile Model S will be closer to the numbers I suggested.
By the way, a 75-amp 220-volt charger is still significant and, for many Americans will require more than a simple plug in or modest hook up. It could require a change of service (for readers: a new line from the pole to handle the added power), a new breaker box, etc.
To be clear, I DO want to see makers find ways to deliver more range. I personally believe the 160-mile battery will help most folks overcome the range anxiety that is largely inescapable at 100 miles or less. But everything comes at a cost, and with battery power it is a lot more than just going from a 9-gallon gas tank to an 18 on your model update.
Paul A. Eisenstein
Publisher, TheDetroitBureau.com
Well, JB Straubel has said that the pack will be 85-95kWh.
http://green.autoblog.com/2009/08/25/report-tesla-model-s-could-have-95-kwh-battery-pack/
Even if they used the very latest Panasonic 3.4Ah cells, then the pack will be at most 97.2kWh.
You are adding padding on padding – there is no way the battery will be as big as you claim.
I stand by my original assertion – “at best require about 14 hours to get back on the road – at best” is simply not true. Not with the math and not in my experience fast charging a Roadster.
From personal experience I can confirm that it’s possible to charge my Tesla Roadster in 3.5 hours using a HPC. Therefore, I have no reason to believe that the Model S battery, at roughly twice the capacity, will take more than 8 hours when charged at 75 Amp.
I would suggest that the only time anyone requires charging in less than 8 hours, is on an extended 300+ mile road trip. This requirement will be easily catered for by using DC fast charge stations that will appear at key locations.
With regards to your comments that a 240V 75 Amp ‘charger’ “could require a change of service” I agree this is true in some locations. However, 200 Amp and 400 Amp household supplies are not at all uncommon in the US especially in more modern neighbourhoods.
Paul: I don’t understand the ‘pad’ you keep talking about. Yes, the Roadster and likely the Model S will protect the top and bottom 10% (20% total) of the battery pack from charging and being discharged respectively. That figure is included in the Roadster’s 53kWh, not added on top of that. If the 300 mile Model S does have a 100kWh pack, the ‘pad’ would be included in that so a standard charge would have access to the middle 80kWh. If you charge in Range mode in the Roadster, you then have access to the ‘pad’ and the entire 53kWh.
Why don’t you accept real numbers from actual owners? The Roadster can indeed go from empty to full in 3.5 hours, I’ve seen it. Why would the 300 mile Model S take 14 hours “at best”? Where do you get these numbers? Like the Roadster, the number they quote for range is when the car is charged in Range mode so there is no pad. In standard mode, which is what you use a large majority of the time, it’s about 80% that number.
Where did you get your figure that the 300 mile Model S would take a couple of hours on a level 3 charger?
If your breaker box is in your garage, the adding a 240V circuit is a minimal cost given the cost of the Model S, maybe a few hundred dollars at most. I had 2 240V 50A circuits installed in my garage and it didn’t cost that much.
People pretty much charge up at home where charging a 300 mile pack in 5-10 hours overnight wouldn’t be a problem for most people. If you’re buying a car like this, it doesn’t make any sense to charge on a 110V outlet. If that’s all someone is willing to do, I wouldn’t recommend they get the car then. Until more DC fast chargers come on line, then you’re right, maybe EVs aren’t the best road cars for people who like to drive 600 miles in a day. If that’s you, don’t buy an EV until fast charging stations are available on your route or they have a 600 mile pack in a few years.
Paul,
dpeilow already pointed out your big math mistake. But I’d like to address your equally large usage mistake.
Charging is not done like filling a gas tank. Drivers don’t drain the battery to empty, and then fill it up. They plug it in and top it off when it’s just sitting around. More like a cell phone.
So 98% of the time, it will charge overnight at home. Even if it’s only 40A on a 50A circuit (which is very common), it could fill a 300-mile battery in around 10 hours. But that would only be required if you drive 300 miles two days in a row. If you drive less the first day, you don’t need to put that many in. If you drive less the second day, you didn’t need it to get full. In short, for daily driving, there will be no waiting, overnight charging is more than enough.
On that occassional road trip, if you drive less than 300 miles a day, there is still no waiting; you can just charge at night. For more than 300 miles per day, the options are:
1. Battery swap if you go near a Tesla dealer
2. DC fast charge. This might be as long as two hours, but only if you are going 600 miles in one day. If you are driving less than that, you don’t need to fill it up. More likely you could just charge while eating a meal, and have enough when you return to finish your driving for the day.
3. Level 2 charging. L2 goes to 80A, which adds more than 60 miles of range per hour of charging. If you stop for lunch and dinner and charge while eating, you could go 420 miles in one day with no waiting. 480 miles if you spend an hour somewhere else–was there a person or site you wanted to visit? Want to go shopping or exercise?
There are of course some cases where it won’t work? No surprise, as there is no car that works for everybody. If you regularly drive more than 600 miles in a day, the Model S is clearly not for you. But “effectively unusable” most certainly does not apply. I have driven my 245-mile Tesla Roadster on a 3,000 mile trip, and with only L2 charging stations (no swappable pack or DC fast charge) it was very usable–pleasant, even. All you need with L2 charging stations is a little bit of planning to make sure you are visiting, eating, sleeping etc while the car is charging. Once battery swapping and/or DC Fast charge is available, I will do all my travel that way.
Paul,
not to press a point that’s already been made, but here’s another math error. You wrote:
“The Model S is consuming 300 watt-hours/mile, which means to do 300 miles will require a 100 kWh battery… BEFORE adding the pad.”
If the Model S consumes 300 Wh/mile, then it would require 90 kWh to cover 300 miles, not 100 kwh, as you have indicated.
300 Wh/mile = 0.300 kWh/mile
300 miles x 0.300 kWh/mile = 90 kWh
Oh, and by the way, Peter Rawlinson’s name is spelled “R-A-W-L-I-N-S-O-N”, not Rollinson, or Robinson…
Apologies, Chris, here I DID do my math wrong…trying to use my fingers and toes when strapped into this cramped Delta seat. Yes, you are right, 90 kWH. But you are not addressing my key points. And, so, instead of 120 kWH with a 20% pad, we’re only talking 108 kWH, still above the 100 number, and that, again, does not include the payback for the added weight, which should still reduce consumption and require even more battery. You seem good at math and should be able to estimate how much the 300 wH figure will grow with the added weight.
Thanks for a reasonable correction.
Paul E.
The trouble is Paul that you are ignoring other people’s addressing of the points – other people being experienced Tesla drivers.
We’ve shown that the maximum pack size based on Tesla’s stated 8000 cells is under 98 kWh. We’ve explained that this includes the padding, so the amount to be charged is 10% less. We’ve shown how much power the charger delivers. There’s no ifs or buts. The 14 hours at best statement is over a factor of 2 wrong.
D, you can tell me max is 98 kWh but YOUR math doesn’t work. If it does there is no pad and/or no 300 miles. You’re also ignoring my other points. I appreciate your comments but the significant thing is that when I ran my numbers by the sources at Tesla they agreed, not disagreed. I wouldn’t have run the story — or certainly would have revised my numbers and any other relevant details — if they had. I spent a good half hour in the conversation that triggered this and had no one refuting my points or offering either clarification or correction. A few details, ie absolute size of the 300-mile battery, were not revealed, though I was told to do the math with the 300 wH/mile figure.
So, while I appreciate your concerns, Tesla did not try to correct me, but actually nudge me to this conclusion. And to date they have not offered anything to address my points in any form. In the past, they have been not just willing to discuss but aggressive at bringing up any issue they disagreed with.
I will be open to discussing all my points with them, if they wish, and will make changes or outright corrections, if justified. I have nothing riding on getting this wrong…if I am wrong.
Meanwhile, feel free to address my other points. But, at this point, to your above, if Tesla is going to yield 300 miles, the battery must have a minimum 90 kWh of usable battery — and that based on the weight of the lighter 160-mile car — which does not include a pad. As has been addressed, ad nauseum, that would be a minimum 20%, or a minimum 18 kWh. Right now, we’re seeing battery packs running in the 25 – 50 lbs/kWh range. Assuming Tesla achieves a huge 1/3 reduction off the best-case number that works out to approx. 50 extra kWh (a conservative compromise number), for at least 800 lbs extra mass. I have not seen any good and reliable numbers for the impact of mass on energy efficiency of battery cars, but there’s no reason to believe that adding a minimum 20 – 30% more mass to the Tesla Model S won’t have a substantial impact on what works out to range. Just a 5% loss would require another 5 kWh to get to 300 miles, but you can check your own sources on this.
NOW…to be charitable, I was told that Tesla is shooting to get below the 300 Wh/mile figure, so perhaps they can make things up there. But remember, 300 is for a car of perhaps 800 pounds less weight to begin with. So, it would be important to note, that model will already be starting at some higher figure to begin with.
Paul E.
Paul, if I recall correctly (and I may be wrong about this), Tesla measures the range of their vehicles in range-mode. I believe range-mode just leaves a 5% buffer at the top and the bottom, for a total of 10% padding. If that is the case, then a 100 kWh battery pack should provide the requisite 90 kWh for the claimed 300 mile range.
As for added weight, I agree that the 230 mile pack will weigh more than the 160 mile pack, due to the greater number of cells involved, but the 300 mile pack should weigh the same as the 230 mile pack as they will both have the same number of cells. The cells in the 300 mile pack will just have a higher capacity. DP probably has the figures on the exact number of Ah of each type of cell involved.
Firstly, 300 miles will be in range mode which uses 90% of the pack, so that tallies with my upper limit on pack size.
Secondly, if we have to charge 90 kWh then we have to charge 90 kWh, regardless of padding. Talk of padding is a red herring. As I said, that equates to 5 hours plus time lost to tapering off during the last 10% of the charge.
Let me put this another way. For the charge time to be 14 hours on the HPC, the battery would have to be north of 220 kWh. If Tesla has found a way to cram that in the Model S, we’ll all be rejoicing.
From Wikipedia:
http://en.wikipedia.org/wiki/Tesla_Model_S#Battery_Packs
The base model will have a range of 160 miles (260 km) when fully charged using a 42 kW·h battery pack (24 kW·h/100 mi, 108 mpgge). Larger, longer range battery pack options will be available as well; the options announced include a range of 230 miles (370 km) from a 65 kW·h pack (26 kW·h/100 mi, 100 mpgge) and a range of 300 miles (480 km) from an 85 kW·h pack (26 kW·h/100 mi, 100 mpgge).[27] The base battery pack will contain 5,000 lithium-ion cells, reported to be sourced from Panasonic, while the larger battery packs will both contain 8,000 cells and weigh approximately 1,200 pounds (540 kg). The largest pack will use the same number of cells, but each cell will have a 30% higher specific energy to enable the pack to store the additional energy.[28] A 45-minute QuickCharge of the 42 kW·h pack will be possible when a 3-phase 480 volt, 100 amp circuit is available (80 amp continuous draw from a 100 amp breaker).
The Tesla Model S is expected to have a swappable battery.[29]
Thanks, Chris. The numbers you quote suggests that energy consumption is notably less than the 300 wH/mile that was unambiguously given me following Tesla’s news conference with the program chief and a number of media standing alongside. He made a point of saying they hope to get that down “a little,” but it would have to drop to around 250 wH/mile, a significant improvement, to achieve what you quote, 160 miles out of a 42 kWh battery, and assuming 95% battery utilization, a major stretch with current LIon technology. Indeed, while D calls padding a red herring, and then suggests Tesla only needs 10%, including both top and bottom, it is anything but a red herring. You must have that extra battery and you pay in cash and you pay in mass. I have a hard time believing, from what I get everywhere else in the industry, from even the most pro-LIon engineers, that going with just a 10% pad is acceptable long-term. We’ll see. No one else is comfortable with this now.
But I digress. And I should stress that I have seen many a promise broken over the years, so while Tesla may have claimed the above figures, I will not believe it until I see it considering the 300 figure is the latest update from Peter Rawlinson — on the record. They may have hoped for a 240 wH/mile figure but they are absolutely not getting it. Plain and simple as of 10 January 2011 as quoted at the Tesla stand at Cobo Hall.
At 300 wH, that would, at the least, require 48 kWh of useful battery and, even at around 10%, a total of 53 kWh of battery loaded onboard.
Again, I have corrected my math (yep, multiply, not divide) for the 90 kWh minimum with a 300-mile range. With a 10% pad that nudges 100 kWh. With 20% you’re at 108, as I have noted before.
Thank you for noting the larger energy density, which fits my understanding, which gets around the issue of a limit to the number of usable cells. But, again, even if the Model S could somehow avoid paying a weight penalty jumping to a larger but more energy-dense battery, that 300 wH consumption points back to my note, below. We can reverse the numbers and determine the difference in weight, and while it would thus be a bit less than the doubling, it is still an addition of hundreds of pounds of mass. Physics make it clear you cannot increase mass so substantially without a moderate to significant energy consumption penalty unless improvements are made elsewhere.
According to Rawlinson (correct spelling here, I believe we can now agree), they are looking for ways to improve things. They have not achieved it.
At the numbers I see, based on Rawlinson’s comments and other sources, a QuickCharge of the 300 would take about 2 hours. Let’s hope there will be a lot of these installed. That’s a lot of time to tie up an expensive piece of equipment.
By the way, folks, please register for comments. You’ll past immediately. I don’t have to approve you. I have no problem with criticism, in fact would like to ensure your points are posted immediately.
Oh, and I have a call into Tesla for some more *official* details about charging and charger technology.
At this point, please allow me to step back and not comment unless there’s a critical post. I am trying to maintain a schedule with the rest of the site and simply can’t get copy written fast enough otherwise.
Thank you for this active dialogue.
Paul E.
Paul,
the numbers used in the Wikipedia page are from April 2009, so they are a bit out of date… I’m quite comfortable accepting the 300 Wh/mile number that you have been using. That would mean the 300 mile pack would have to be 100 kWh, including the 5% buffers at the top and the bottom of the charge.
Just for clarification, Tesla does not recommend using range-mode all the time, only when it’s needed, and on the understanding that excessive use of range-mode will result in a faster degradation of the battery pack. At least that was the case with the Roadster.
I don’t know if you’ve had the opportunity to drive the Roadster yet, but if you get the chance, take it. It’s mind blowing…
For the charge time of the 300 mile pack, I get 2 hrs and 20 minutes (for 90kWh) on the fast DC charger (480V @ 80A), and 5hrs 22 min. on the Tesla HPC (240V @ 70A). This doesn’t account for the slow-down in charging rate for the last 15% or so, so I would be comfortable rounding up (for the sake of estimating…) to the next full hour in each case (i.e. 3hrs for the DC fast charger and 6hrs for the HPC). In any case, I think that it would be significantly less than 14 hrs.
All the best…
Thanks Paul. Can you please explain why you keep adding the pad to the size of the battery pack? At least in the Roadster, it comes with a 53kWh pack and normally run in standard charge mode (you charge up to 90% and are allowed to discharge down to 10%). I think you’re getting confused with the mileage estimates and the size of the battery pack here. When Tesla advertises the Roadster at 245 miles, they’re not telling you that is in ‘range mode’ which is a mode that is not normally used since repeated use can shorten the life of the battery. in ‘standard mode’, the range is actually closer to 180 miles.
This is the same thing I think you’re getting mixed up with the Model S. The 300 mile pack will likely only have a 300 mile range in ‘range mode’ with a conservative driving style.
Have you driven a Roadster? Do you understand the different charge modes and what they mean in terms of range? I think you keep seeing the number Tesla quotes for range and try to use that number to calculate the battery size using ‘standard charge’ mode (middle 80% of the pack) then add on the pad you keep talking about. It doesn’t work like that. Telsa starts with a certain battery pack size and does mainly 2 things:
1) range mode: you have access to entire pack and it cuts performance to get you the biggest range possible so in a Roadster that’s around 245 miles if you drive conservatively
2) standard mode: you get access to the middle 80% of the pack so start and around 180 miles or so.
Does this make sense? People have pointed out multiple times that you’re adding this battery pad on when it’s included in the battery size. dpeilow understands this much better than I do but I believe I have this correct. Someone correct me if I’m wrong. Thanks.
Hi, DSM,
No, I am not confusing things, though range mode/standard mode figures make this easy. As your colleague suggests, even if the longer range mode is 300 miles, there’s still an extra 10% of battery going along for the ride, so to speak. So, even assuming your more conservative guidance, if we took 300 miles at a minimum 300 wH/mile, you are still loading up at least a 90 kWh battery, minimum. And to that you add 10% — which, as I say elsewhere in this thread, is just going along for the ride — bringing us to roughly 100 kWh actual battery onboard. I don’t care how much is used. Engineers don’t say, well, we don’t expect to use the airbag, therefore I will give you a weight for the vehicle without it. You must calculate mass, volume, etc., with everything figured in. And even if I were to concede a smaller figure, ie 100 kWh — which I am not yet convinced of, as I will explain — that adds a lot of mass over the 160 mile (range mode, if you wish) battery. Add that extra weight and you’re going to require more than 300 wH/mile. I’ve already made this point earlier, so I won’t repeat myself. Key is, reduce efficiency just 5% and you’re adding roughly another 5 kWh battery.
Paul E.
Let me be clear – if the Model S is labelled in the same way as the Roadster, then that is 300 miles is “ideal miles” in range mode.
Range mode, as I said above, is what gives you 90% of the capacity of the battery. Standard mode only accesses 80%. Range mode is to be used sparingly, precisely because it does impact on battery lifetime. Tesla are quite open about this, there is a dialogue on the vehicle display when you select range mode.
Your original point was about charge times. That depends on how much you need to charge – not unused padding, weight of the pack or cost. That’s why I said all that is a red herring.
Gotcha on our difference re padding, D. To me, it is not a red herring because it is still mass, volume, cost, etc.
Paul E.
Hi Paul,
could you moderate my two posts from yesterday afternoon so that they can be part of the conversation? Please & thank you…
Chris H.
Paul,
regarding the extra 10% capacity of the battery pack that is “just going along for the ride”, consider that with an internal combustion engine vehicle only about 20% of the energy in the fuel is used to propel the vehicle forwards (or backwards…), and that the rest is wasted as heat, noise, vibration, and idling. All of a sudden that 10% or 20% of the battery pack that functions as padding doesn’t seem so bad. Roughly speaking the average electric vehicle is about 4X more efficient in terms of energy usage (from “tank” to wheels; well-to-wheel is even better…) than your average ICE vehicle.
One of the benefits that ICE vehicle enthusiasts tend to overlook when it comes to EVs, is that the TCO (Total Cost of Ownership) is lower for an EV than for a comparable ICE vehicle. Petrol heads (excuse the term) tend to look only at initial purchase price and conveniently forget about all those $50+ fill-ups, all those $30+ oil changes, timing belts, exhaust system costs, air & fuel filters, etc., whereas EVs, by comparison, are virtually maintenance free. Tesla has estimated the TCO of the Model S to be approximately the same as a $35,000 ICE vehicle. Imagine for a moment that the Model S is a conventional ICE vehicle (with the same specs, ride/handling, build quality, etc.). Do you think that it would be worth $35,000?
Chris H.
Paul: You don’t need to keep adding on 10% to whatever figure you come up with. That extra 10% is also there on the 160 and 230 mile packs as well. It’s there on the Roadster’s 53 kWh pack too. It will always be there on a Tesla. That’s just part of the charging strategy. The 230 and 300 mile packs will probably weight about the same but with different chemistries. Again, that 10% unused portion is part of the final number (around 90kWh) not added onto it. That 10% can be used it is just not recommended.
As dpeilow said, that’s ‘ideal miles’ anyway which isn’t the most accurate. The ‘estimated miles’ is much more realistic.
The Roadster has this padding as well. It’s just part of the battery and I’m not sure why you’re focused on it. Maybe the 300wH/mile figure isn’t totally accurate that you were given. It also varies on how you drive so it’s not a fixed 300wH/mile number. Why not wait until official numbers are released before calling it ‘effectively unusable’ which I think is a little irresponsible.
Yes, a bigger battery pack will weigh more. What’s the issue exactly? Tesla allows you to use 90% of the pack easily and 80% of the pack on a normal basis. Yes, you’re carrying around a little extra weight when you charge in standard mode but that’s the same regardless of the size of the pack. 80% of any number will always leave 20% left that’s along for the ride. That’s just part of how Tesla does it. They could charge to 100% and down to 0% like you seem to want them to do but that would harm the battery over the long term.
Please call the Tesla press office as you’re doing so you can talk with someone who can explain this to you and you’d have time to ask some questions.
Paul,
some of my comments have been awaiting moderation for over 24hrs now, despite the fact that other comments that were posted later have made it through.
Did I violate commenting policy? I’m starting to feel left out of the conversation…
Chris H.
Tom,
The premise and subtitle of your story is that the 300-mile battery pack in the Model S is so large it will take an impractical amount of time to charge. You quote a time of 14 hours “at best” to charge the battery. This is wrong, and not just a little wrong, wrong by at least a factor of two.
You claim that you checked your facts with Tesla, but I’m sure you didn’t confirm that charging the 300-mile Model S will take at least 14 hours. If they did, you were talking to the wrong person or they misunderstood what you said. None of the base facts you site support this number. I’ll explain how to do the math correctly.
Let’s go with your figure of a 100 kWh battery, with 90 kWh available for use. If the battery is full depleted, that means you need to put 90 kWh back into the battery. Although you don’t have to replace the amount of charge in the pack that corresponds to the safety padding since you never took it out, there are some losses in charging. For the Roadster, about 85% of the power you draw from the wall goes into the battery pack. Doing a bit of math, 106 * 85% = 90.1. So, you need to pull about 106 kWh from the wall to charge Model S all the way up.
The best J1772 charger on the market right now, the Clipper Creek CS-100, delivers 240V at 75A, or 18 kW. The J1772 spec goes allows up to 80A charging, 19.2 kW, but let’s use the lower value.
106 kWh divided by 18 kW is 5.9 hours. That’s less than half of the 14 hours you quoted, and easy overnight charge. With a DC fast charger, you get as much as 60 kW, which yields a charge time of 2.12 hours, or about 1/7th of the time you quoted as best case.
These numbers will slightly underestimate the charge time because the current applied needs to be tapered off near the top of the charge. So that will add a little more time for a full charge. You can read about how this all works on my blog: http://www.saxton.org/tom_saxton/2010/06/ev-range-and-charge.html
But there’s a bigger problem in your logic and that’s thinking of charging rates in terms of how long it takes to get a full charge from empty. That’s a case that rarely happens, even on a long road trip. If you’re trying to drive over an EV’s single-charge range in minimum time, you only charge (at most) until the current starts to taper around 90 or 95%. Having a big battery only helps on the first segment of the drive, delaying your first mandatory charging stop. After that, your net travel speed depends only the charging rate. A Nissan Leaf with DC Fast Charging will beat a Tesla Roadster with Level 2 charging on a sufficiently long trip.
Here’s the right way to thing about charging rates: in miles of range added per hour of charging. Let’s assume that the Leaf, Focus, Model S and Roadster get about the same energy efficiency: 300 Wh per mile. That won’t be exactly right, but it’s probably with 10%, definitely within 20%.
Nissan Leaf, Level 1: 4.5 miles/hour of charging
Nissan Leaf, Level 2: 12 miles/hour
Ford Focus, Level 2: 24 miles/hour
Telsa Roadster, 16.8 kW HPWC: 61 miles/hour
Nissan Leaf, 50 kW DC Fast Charge: 80 miles in 25 minutes, or 192 miles/hour.
By the time the Model S comes out, I expect there will be full 19.2 kW Level 2 chargers available, the charge rates for Model S should be within 10% or maybe 20% of this:
Model S, Level 1: 4.5 miles/hour
Model S, 6.6 kW Level 2: 12 miles/hour
Model S, 19.2 Level 2: 70 miles/hour
Model S, 60 kW DC Fast Charge: 217 miles/hour.
One other correction: the on board charger for the Focus is around 240V/30A or 7 kW, not 75A. By the time the Ford Focus ships, I’ll bet Nissan will have upgrade the Leaf to a comparable on-board charger.
Working around your long and useful note, Tom, let me start at the bottom. Nissan officials say they will not be running a larger charger on the Leaf because of weight issues. We’ll see if they change positions if customers demand it.
Meanwhile, for clarification’s sake, Khobi Brooklyn has just e-mailed me a bit of data putting the charging time at 5.4 hours on the 75A charger. So, if one has the ability to handle that much power that’s tremendous. Per my earlier notes, I believe that the number of folks who can will be limited, as it is, by itself, about as large as the actual electric service in most American homes. (The last several I had were 100 – 150 Amps on 110 until I upgraded, and a few calls and some online research suggest I am spot on here.) Whether condos, commercial garages, etc., would also upgrade remains to be seen.
Certainly, to handle a 19.2 charger would, according to my electrician, run a minimum $5,000 or more for the service from the pole, the box, the wiring to the garage, etc. It may be higher. He has handled my previous upgrades and was usual pretty close to target.
Bottom line, while Khobi’s numbers WOULD suggest overnight charging is realistic, that assumes having one of the most powerful chargers on the market and the ability to “pump” the necessary amount of current into it. I don’t believe this will be as common as everyone seems to be suggesting, in part because of costs and limitations. Also, this assumes that you will be able to get back home all the time to charge if you have the pipeline. If I go with the 300 mile battery and drive, say, from Detroit to Chicago, or NYC to Boston, how many of the public stations at the other end will be able to deliver that much current? I am preparing to wire up my own garage, for example, and will likely have a significantly smaller circuit available than the top Tesla charger would require. Under that circumstance, my charging times will be the number I quoted.
I DO appreciate the POTENTIAL for even faster charging. But, realistically, I think the number of folks who will be in my situation will be closer to the norm than the exception. Sadly, Tesla declines to provide any information showing what their customers actually are doing
Oh, and Khobi’s note seems to suggest the 90 kWh number for the actual useful portion of the battery, though, again, I believe it will be higher, as the mass of a larger battery will result in lower energy efficiency v the Model S with the lighter, 160 kWh battery, on which Tesla is getting the 300 wH/mile consumption data. We’ll have to see if the ultimate battery actually meeting the range target comes in at 90 or higher. I’m hoping I AM wrong and that Tesla pulls it off by further improving the Model S’s energy efficiency.
Paul E.
Paul,
why are you not letting my comments through? I have 5 comments “awaiting moderation”. The longest one has been pending for over 28hrs now.
If I have violated a specific commenting policy, I would appreciate it if you could send me a link to your policies, and indicate which one I have violated and when I violated it. Otherwise, I would appreciate it if you would allow my comments into the discussion.
Chris H.
Chris, I am letting your stuff through as soon as I see it. Be aware that I am not at the computer 24 hours (I have been in the field for much of the day and will be out of pocket for the rest of the evening. I am about to check to see if somehow you got stuck in with spam but I have released everything I see. Please register. Not sure why SOME registered folks’ comments aren’t immediately posting. I will talk to techs, though they will be working all week on a site upgrade and a fix to some minor but nagging e-mail issues.
Be aware that I never block critical comments, even embarrassing ones in the event I get caught up in a mistake, only serious obscenities or true spam.
I thought if we registered that posts would get added immediately without the need for moderation?
Anyway, as was stated before, you almost never need ultra-fast charging at home and certainly don’t need to get the fastest charger on the market for $5,000. The Tesla HPC is $2,000 and goes up to 70A and installation shouldn’t be $3,000. If you can’t install something that can handle the Tesla HPC at 70A, the mobile charger goes to 40A on a mobile charger. It chargers the Roadster in about 6 hours and I guess the 300 mile pack in about 10 hours on the Model S depending on the size of the pack. Almost every home should be able to do a 30A outlet (dryer outlet) and maybe even a 50A without great expense.
I know two owners who have the Tesla HPC and can charge the 53kWh Roadster in 3.5 hours so it is possible and is done. If your point is that the charging infrastructure isn’t there then you’re right. It’ll take time to build that out but until that time, traveling long distances will take planning and patience. That may not be for everyone and those people should probably hold off on buying an EV but for 80+% of the population, I think EVs will be great, at least as a second car for a family.
Hi, D,
Yes, the issue of infrastructure is as much what I am trying to address with this story and others. The conversion to battery-based propulsion has landmines everywhere. (See my piece on the issue of replacing gasoline excise taxes.) We need 1) acknowledge these issues and 2) deal with them. And, to be blunt, if the roadblocks cannot be readily overcome, or require effort that might be easier handled elsewhere then a valid debate must occur. (Hydrogen v batteries anyone?)
Your point about a dryer-sized powerline gets to my point. Yes, by the way, almost every home CAN handle a 30A circuit…but can they handle two? How will my neighbor feel when they discover they can’t use the dryer at night because the battery car is charging? Let me tell you, my wife was enraged when I nearly ruined her New Year’s Day party trying to charge the (tester) Volt which kept blowing the circuit breaker for her crock pots. Good news is she’s now quite willing to let me spend the money to run a 220V line into the garage even though we don’t actually own a battery car!
Paul E.
Hi Paul,
I’m glad you’re able to get your garage wired. Make sure you get the highest rated line possible and run whatever wires you’ll need the first time since it’s trivial to upgrade certain components but if they have to dig a tunnel like they did for me (have breaker box 30ft from detached garage), then you want everything in place the first time. I’m sure some homes need to have their electrical system upgraded before handling higher power devices like an EV. I’m sure if you tell your electrician what your plans are and what you’re looking for, they can install the system you need.
I can’t see how charging an electric car would affect your neighbors but I guess it’s possible. I’m in a fairly old house but they were able to install 2 separate NEMA 14-50R outlets (each 50A) without a problem. That means I can charge two separate EVs at the same time if I needed to in the future. I’ve been charging for a month now without any trouble.
At this point I think people need to understand that EVs are not for everyone, especially if they take frequent long trips and it’s their only car. I’ve driven over 1000 miles in less than on month in my Roadster and it’s been a blast. I plug it in as soon as I get home and start the charging process. I actually dropped the charging from 40A to 32A since I didn’t need it to charge so quickly and thought it’s be less strain on the grid.
Now that you’ve established that the ‘The larger Model S, with its huge 300-mile battery, would, at best require about 14 hours to get back on the road – at best’ part of your article probably isn’t accurate, maybe you can put a correction at the end of the article with your new information and everything you’ve learned both from Tesla and from current Roadster owners. I’m not sure everyone reading this article is going to go through all of the comments. Thanks.
Paul,
thanks for your attention to the matter. I did register yesterday, before I made my first comment, but I guess there’s a bit of a bug in the system somewhere.
Chris H.
Have you collected data on what the typical home service amperage is among those who can afford a perhaps $100,000 300-mile Model S? I know a lot of Roadster owners and they all have either the 70A HPWC or a 50A outlet for the mobile connector, either of which can charge a Roadster from empty to full overnight. I have the HPWC and only charge at 32A because that’s more than enough for my driving and it’s a bit nicer to my electrical panel and the grid. Even at that modest power level, my typical charge is around 2 hours.
If your house can’t take a big charger, or the expense is prohibitive, then put in a smaller charger. As several have said before me, unless your driving habits are wildly inappropriate for an EV, you don’t need fast charging at home, you need it on the road.
Even with just the weakest 120V charging, you can pick up enough charge to do a 40-mile commute and get back to a full charge with just 9 hours of charging. The bigger pack gives you more room to put in the occasional 200-mile day and then work your way back up to a full charge over a few days.
Remember that when people first starting buying and driving gas cars, there were no gas stations. People bought gas in gallon cans in hardware stores.
As for charging your EV taking out your neighbor’s power, you should talk to some utility people. I was at a Washington State Utilities and Transportation Committee meeting last fall with all of the local utilities represented. None of them were worried about the adoption of EVs. They need to know where EVs cluster so they can proactively monitor and upgrade local transformers as needed, but the load of EVs at even the most optimistic production rates are not going to be a problem. They went through this when hot tubs became suddenly popular and they know how to deal with it.
FYI, I didn’t say I took out my neighbor’s power. I DID repeatedly pop a circuit that turned out to be shared between my outdoor plug and my dining room, where my wife had set up the crock pots.
Oh, and as to 120V charging, I have had about 10 different battery cars plugged in (usually WITHOUT anything sharing the circuit) in recent months. Whether I got 50 or 15 miles range on that 20A circuit depended on a variety of factors including the outside temp and whether I was willing to look like the Michelin man or expected a comfortable cabin. During the numerous deep freezes we’ve experienced in Michigan, this Winter, I have seen ranges plunge horrifically.
A key point to all I have been writing (and responding) is that we cannot simply tell the public “everything you know, want and need of an automobile goes away with the switch to batteries.” Certainly, creature comfort is something people won’t give up, en masse. Yes, seat and steering wheel heaters help, but ultimately, people want a cozy cockpit, and the trade-off on a 0-degree day is significant in terms of range.
Paul E.
So what you are saying is that Tesla has confirmed the numbers that I and several others have been trying to tell you for the past few days are correct. You’ve now tried to shift attention away to other issues but let’s concentrate on the original story.
You made comments such as:
“For the record, Rollinson and other Tesla officials are not commenting, but sources confirm TheDetroitBureau.com’s math. And there are even more problematic numbers.”
and:
“The larger Model S, with its huge 300-mile battery, would, at best require about 14 hours to get back on the road – at best.”
…which are patently not true.
You’ve tried to shift attention onto other issues such as weight. Firstly, the 300 mile Model S has the same number of battery cells as the 230 mile version – it’s a different chemistry – and thus the weight difference over 8000 cells is at most a few kilos. Secondly, weight has a far smaller effect on range than aerodynamics at highway speeds.
Even your comments about DC fast charge are not accurate, for example I know there is a public DC charger at Vacaville, CA. Furthermore, as the coming J1772 DC standard supports up to 120kW charging, if Tesla decided to use this then the car could charge in under an hour at such a station.
The premise of the story has been thoroughly discredited. The honest thing to do would be to rewrite it.
The honest thing to do is let these comments get posted and raise serious discussion.
Secondly, the story is “discredited” only if you assume the most aggressively positive presumptions:
*Tesla achieves a 30% improvement in energy density:
*The maker can actually reduce the energy usage of the 300-mile-range vehicle BELOW the 300 wH/mile consumption of what Rawlinson said, this month, they have barely struggled to deliver out of a vehicle with a smaller, much lighter battery;
*That buyers all, or to a very significant degree can AND WILL put in place what is, by American standards, a massive energy pipe, delivering service of 75A at 220V to their garage chargers;
And there are other issues. We have not seen anything to confirm the first two stretch goals, and Tesla notably declined to provide ANY corporate data revealing what number of users actually do have the capability of delivering power at the max needed to make use of the 75A charger’s capabilities. Simply reducing that to what is now the most common high-power service, ie a dryer or a top-end electric range/over combo, brings the figure down to 30A, or thereabout. Suddenly, if that’s what you’re delivering, even with the potential of the 75A charger you are talking charging times much, much closer, even longer, than my report.
If a revision need be made, it is this:
Under the most ideal circumstances, using the extreme charging capabilities that Tesla is offering, charging times conceivably can be reduced to as little as perhaps 5 hours or so — the exact time eventually to be determined, in part, by what engineers will ultimately need in the size of the battery to get 300 miles range.
The California start-up has declined to provide information on how many of its first-generation buyers, the several thousand early adopters who have dropped $100,000 for the 2-seat Roadster, have actually set up their garages to maximize their charging in line with the capabilities of the Roadster’s 75A onboard charger. Nor will Tesla make projections of how many are likely to do so when the Model S comes to market. There are numerous skeptics who doubt that the numbers will be significant for those installing such a large “pipe,” which can add significant costs, and may not even be possible to install in older homes, condos or apartments.
Simply trimming the amount of power to that of a high-demand electric dryer or a large electric range and oven — typically the largest circuit in a modern home — would stretch out charging times to times of 10 hours, perhaps substantially more.
So, it is anything but certain that most users will find it cost-effective, even possible, to go the truly fast-charge route, however it must be stressed that the capability does exist and may come into wider use over time.
That, my friend, puts things into a perspective I am willing to accept. Your points are taken, they are reflected. As are mine, which have not been shown to be incorrect except under the most idealistic situations — which no one is providing me data to validate, except in the abstract, as a best-case application.
And, at this point, I have spent far, far too much time going over and over the same points. I will be glad to comment on new issues. I will encourage and appreciate your additional posts. But I’m going to continue debating ad infinitum. The above is the situation as I see it.
Paul E.
Also, it’s not anyone’s guess how quickly fast chargers will be added. The US is about to install 310 of them here: http://www.greencarcongress.com/2010/12/report-us-to-test-japans-chademo-quick-charging-system-for-evs.html#more
BP are going to install a further 45: http://www.greencarcongress.com/2010/10/bp-to-install-45-ecotality-blink-dc-fast-charging-stations.html
Nissan is also installing them at dealers.
These are just the stories I can find with a 30 second search…
D, How many service stations are there? How many pumps. During any period you define: prime hours at the “pump,” a 24-hour cycle, middle of the night, etc., how many vehicles will these and 10 times as many quick chargers actually accommodate? I drive the Tesla Model S from Detroit to Chicago (or LA to SF or NYC to BOS), will I be likely to find one, even then? Will it be free or, if not, how long will I need to wait? Do I really need to spell out the legitimate questions.
I get the key use of home charging, but let us be honest, if/as we migrate to longer-range batteries, if/as the number of battery vehicles goes more mainstream, and if/as we expect those vehicles to serve a more conventional, mainstream use by consumers, rather than forcing American motorists to redefine their lives around battery power, what will the real infrastructure need be? An earlier post noted the ACTUAL charging time of a drained Tesla Model S. How many chargers will we need at the Truckstops of America if even a moderate amount of longer-range battery cars hope to drive in and get out in reasonable time?
If we assume that a typical user will need in excess of 20 minutes, (never mind the 45, 50, 60 or more that some battery vehicles may still require at 440V), BP will be able to handle, on an absolute best-case scenario, 135 vehicles an hour, perhaps 3,000 a day. That’s if the all comfortably lined up and were happy to wait as necessary, etc., and evenly spaced out 24 hours a day.
What will be the cost of using that high-voltage charger? Nice of Nissan to subsidize dealer chargers…for now. Will they do so longer-term? See another comment here about getting the economics in place so that utilities (or whomever) will be able to make the necessary profit to invest in the infrastructure.
These are all the points I could type up in 30 seconds. (Okay, more like 90…but I hope you get my point.)
Paul E.
As I stated previously, 200 Amp and 400 Amp domestic service is not at all uncommon.
That said, my 100 Amp service is perfectly adequate for running a Tesla HPC and I never have any of the problems that you suggest are roadblocks to the deployment of EV’s.
Clearly we will need to upgrade some of the electricity infrastructure, but given the potential growth in profits of a switch from gas to electricity I’m sure the power companies will find a way of funding the expansion.
One final point, you are quick to dismiss the views of long term EV drivers and to use quaint stories about your experience with a (tester) Volt. Why don’t you actually undertake a long term trial and then write from experience rather than conjecture?
Kevin, “Not uncommon” is a potentially misleading term. I’d like to see your hard data as to actual percentages. My understanding is that 400 is rare, even in the mega-mansions that fluourished over the previous business cycle peak. Yes, 200 is more common, but usually requires a conscious effort to install it. It may be more frequently available, at construction, in larger modern homes but is not routinely available on anything of more than a decade or so ago, according to my understanding.
I upgraded twice in an older but fairly high-end home before getting to 200 and that level of service is NOT common in my community.
Easy enough? More or less. Required my replacing the line in from the pole, a by-the-foot charge that ran into the thousands even though my lot is not especially large. Then I had to completely replace the box. Now, running a line to the detached garage — something NOT uncommon, either, in older communities — would add significantly more.
I had a long discussion with a major maker’s senior exec (off the record so not ID’d here) this afternoon. The person has authorized EV efforts but mentioned themself their concern about getting charging infrastructure out there, especially in urban areas. When I mentioned higher-amperage charging (never mind 440V), the response was, effectively, “not gonna happen,” according to their data.
Do you really expect even high-end condos to be running numerous 75A lines into their garages for EV charging?
BTW, your 100A can handle a 75A Tesla charger? I assume, then, that you make sure to absolutely shut down everything, even the refrigerator and certainly the A/C, the plasma screens, etc.? I already assume you’re only using fluorescents and LEDs.
(I have been steadily migrating to more efficient technology, so you understand where I come from.)
I have been working with battery cars for 20 years, not just a tester Volt, FYI. I would love to arrange a long-term test and am talking to several makers. Even without having a permanent or long-term vehicle I AM investing in the high-amp 220 line to my garage, as I alluded to in earlier notes.
I have probably spent more time than any non-specialist media driving, testing, working on, researching and generally coming to know EVs and related technologies. That I question the challenges involved in the infrastructure seems to generate as much frantic concern as it does serious discussion and debate (though I appreciate the reasoning of many who have picked up on my, ahem, gauntlet here and in other outlets, ie Autoblog). In the conversation, today, my source echoed my key point: unless we seriously and event aggressively bring into the open the challenges of migrating to new powertrain technologies we risk having those issues bite us in the butt. The true opponents will eventually use them against the technology and clear answers, not hope and faith, will be the only way to respond.
I bring this up because of your third graf. Yes, thank you got acknowledging the need for building up the infrastructure, but I am NOT sure the power companies “will find a way of funding the expansion.” That will happen only if and because: 1) they can clearly make a profit, and a good one, not fractional percentage margins; 2) the path to electrification is solidly defined, rather than something vague and built on the if-come, supported more by hope than anything else.
Selling electricity at massively reduced rates in the middle of the night may have some advantages but, long-term, I guarantee you this won’t be enough.
I was disappointed not to generate this level of discussion when I posted another recent story raising questions about the issue of fuel excise taxes. So, let me toss this out to get people thinking and debating. Here are two links:
http://www.thedetroitbureau.com/2011/01/green-cars-%E2%80%93-red-ink/
http://www.thedetroitbureau.com/2010/12/are-you-ready-to-pay-by-the-mile/
Before I get (potentially assaulted), I will stress that these pieces are intended to raise a critical question. There are plenty of issues to debate in my research and logic…no doubt, the switch will occur over significant periods of time…but the fundamental points of the discussions are essential.
The debate is deep and the answers, despite reasons for hope and faith, are anything but clear. I recall how we went through a similar episode with hydrogen power. I am a cautious, even skeptical, proponent of electric propulsion. But there are plenty of reasons to want answers before joining the church.
Paul A. Eisenstein
Publisher, TheDetroitBureau.com
Paul,
Since we’ve shown that the subtitle of this article and the support statement about 14 hour best case charging are totally wrong, could you please fix those statement?
If you want to write about the other issues you have brought up, that would make for an interesting article, but the current piece is just wrong.
See one of my other comments, Tom. The piece is only “wrong” under a best-case scenario. When Tesla (and other makers) show that a serious number of Model S owners and those who might purchase BEVs from other makers eventually offering long range batteries not only can potentially, but actually do, use the high-power, high-speed chargers at their most powerful settings, then a revision might be justified. But, as I warned I wouldn’t do, I am just repeating points from my other notes of this evening. Please see them for a longer response. And, again, I will sign off unless some very clear information to change my position, stated here, is demonstrated.
Paul E.
Paul: I think it’s safe to say the piece about ’14 hours at best’ has been proven wrong so I don’t see why you won’t correct it. If anything, it’s 2 hours at best (DC fast charging) and 5 hours under an ideal home charging setup.
Panasonic is coming out with cells that have 55% more energy density that the cells used in the Roadster. They are already delivering cells with about 40% more density. For your second point, would this not allow the Model S to go 300 miles with your 300 Wh/mile usage?
Your language always seems to be loaded “Under the most ideal circumstances, using the extreme charging capabilities that Tesla is offering, charging times conceivably can be reduced to as little as perhaps 5 hours or so.” Why is a 70A charger extreme? Out of the 3 Roadster owners I know personally, all of them have the 70A HPC installed. I’m the only one with the slow, 50A charger. That’s not scientific I know but it’s not rare.
I can’t imagine many Model S customers will actually try and charge their car over a 110V outlet. I’m sure someone will when necessary but anyone buying a $50,000 plus car will likely spend the $500 to $1500 to have a 240V outlet installed in their garage.
Aside from the very serious elementary math errors, you are still wildly misrepresenting how electric cars are charged. More than one person has explained this already; maybe you just need to live with one for yourself a while to understand:
Nobody will ever wait for the full duration of a complete charge unless they already used the whole battery pack AND they are going to use the full battery pack again right away. There is no reason to wait under any other circumstance.
24A or 32A charging (dryer-sized) is all that is needed at home–that’s what I use for my 245-mile Roadster. (I, like many, didn’t install the 75A amp charger. I would never use it at home!). They only need faster charging if they go 300 miles two days in a row (in which case 75A is more than enough even if you are only home 8 hours at night); or if they are on the road going over ~400 miles (75A is fine until then too) in one day. DC Fast Charge will be plenty fast for up to 600 easy miles per day (charge while eating); 900 miles for the dedicated (have another break somewhere).
Yes, this means that (like any car) there are a (very) few people the car won’t work for. No surprise there. But “Effectively unusable” is completely incorrect.
Chad,
I made a quick error, earlier, on the size of the 300 mile battery and quickly acknowledged and corrected it. The number of other errors in this chain has been significant, and many are errors of omissions or perceptions by those trying to convince me of something they want to believe by faith alone. My words have even been turned upside-down, my being accused of calling 14-hour charging a best-case scenario.
Everyone keeps trying to convince me (and, apparently, themselves) of what they think I am writing and what reality is. And when folks like yourself, deliver comments to support my point, they ignore the irony.
(Oh, and D, when one says, “14 hours at best,” that means, the best you can expect under that circumstance, not that this is the best thing to do. I can get from 0 to 60 in one of my cars in 8.7 seconds, AT BEST. Had I opted for the big V8 it would’ve been 5.4. Don’t try to trip me up by twisting semantics when my point is obvious and clear.)
Yep, thank you for pointing out that 24A or 32A charging is all you need. And thanks for being the first in this thread to point out that a 75A circuit at a home isn’t necessarily the answer.
Now, let me agree with YOU…for folks who are largely running around town, who generally come home at night and “fill up” by recharging the moderate amount of energy they used during a typical day, this is great. You can live with a battery, you can handle home charging.
For someone who opts for the 300-mile battery, but who typically will use it just around town, recharging at night after maybe 40, 80, even 100 miles, using a 24 A or 32A charger will be easily accommodated.
But those willing to pay what will be a HUGE penalty for the 300-mile battery will do so for a number of reasons, including:
1) They just have serious range anxiety and don’t feel comfortable unless they have the equivalent of a gas tank’s range;
2) They aren’t going to charge up every night at home and will handle charging more like folks handle refilling a gas tank. This could be because of habit, or perhaps because they live in a situation, ie a condo, apartment, etc., where they don’t have ready access to a charger each night but will hope to get to a 440V station, or such when away from home;
3) They actually plan to use a significant portion of the battery. This could be the one time a year when they go visit grandma in San Francisco, or like friends with a daughter in gymnastics, need to get to the regional meets every couple months, or so on.
The key point is that if you are selling a 300-mile battery people SHOULD…and do have a RIGHT to know what they can expect. So, it’s all well and good for everyone on this thread to be telling potential buyers, “Hey, if you go with the 75A charger, and you can ALWAYS charge back home, you’ll be able to get that thing recharged, even when fully drained, in 5 -6 hours.”
But would you be happy if your car salesman completely failed to tell you about the issues of going with the big charger? Like failing to mention how much current it draws, or the price, etc. Clearly, Chad, you made the decision to go with a smaller charger for reasons beyond not liking the color of the charger! And so, if you were to go to grandma’s and make it back on one charge, but have the battery drained, you are going to be plugged in for somewhere in the range of the 14 – 15 hours I’ve been reporting, maybe more.
Now, here is a WORSE (not necessarily worst) case scenario: You use your 300-miles to go from Seattle to Tacoma, or whatever distance that would leave it limping. You check into your hotel, which advertises having a charger, and you find it’s a 15A/220V set-up. Instead of 5-6 hours, you’re spending a day at the hotel waiting. (Yes, I know, you’ll get enough for 80 miles of sightseeing the next morning, but at some point you will need a full charge at home.
(BTW, a media colleague from Jalopnik, which picked up my original story decided to do some research himself. I believe their story is posted…noting the extent to which they had to hunt to find a public charging facility that actually worked around NYC. ((There WERE plenty available.)) Please pick up that debate by starting a thread on Jalopnik. I am only relaying this matter.)
So, while most everyone who has been adding to this thread continues to try to get me to somehow close my eyes, click my heels and envision a perfect world where everyone has a 75A 220V charger, in which there are 440V stations everywhere on the highway, where people actually never use 300 miles and ALWAYS charge at night, the collective group has been angrily accusing ME of lying by not simply accepting that the more perfect scenarios they envision are the ones that should be portrayed.
Folks, if I have a 300-mile battery, I am going to use it to go to Chicago, as I currently do in my gas car, regularly. I will use it on my other runs, which often mean going to Lansing or Grand Rapids from Detroit, which will clock anywhere from 170 to 250+ miles round trip. I likely will NOT install a 75A circuit in my garage, but a 25A or 30A. (No one, by the way, has even addressed building codes in this thread. One of the auto execs mentioned, last night that not all communities would allow 75A, but that’s another story.) I won’t always charge overnight; though I usually do when I have a battery car I have, on occasion not plugged in. And so, like Chad, if I really run the battery down, I am going to be waiting a significant amount of time. How often? Maybe only once every week or two…but I acknowledge that WHEN USING THIS BATTERY TO ITS FULL CAPABILITIES, that is what I can expect to experience.
Best case? I get a 440V charger installed at the nearby BP and the line isn’t long. But that is a best case. Under more normal circumstances, fully utilizing the battery I purchased would require charging times in the range I repeatedly point to.
Let’s be honest.
And, folks, that really is the limit of what I have to say. I don’t intend to battle you on perceived semantics, etc. I corrected the math error on the size of the battery, and even Tesla has not acknowledged the critical point I made that the added weight with the 300 will actually lower efficiency, requiring still more battery. I have acknowledged that a large charger can, ideally, cut times. And I appreciate Chad’s adding to the conversation by personally noting the entire world won’t be using those 75A chargers.
Now, when there’s more to report, new developments in battery tech, details of the Tesla SUV they selectively leaked only to Edmunds.com, etc., let’s reconvene this meeting.
Thank you all. Now, I have five or so stories to post today.
Paul E.
Paul,
you said:
“The piece is only “wrong” under a best-case scenario.”
That is simply not true. The “best-case scenario” is the J1772 DC high power charger (600V @ 200W = 120kW) that is currently under proposal. This would be capable of fully charging a 100kWh pack (with 10% padding, i.e. 90kWh) in less than one hour. This would obviously have to be a public, or commercial, charging station. And before you respond that this charging option is not currently available, let me remind you that neither is the Model S. In 18 months time (or thereabouts) when the first Model S is delivered, the new J1772 DC standard should be just around the corner.
In the meantime, there’s the ECOtality Blink DC Fast Charger (60kW max), which should be able to handle the job in about 2 hrs (again, it would be a public, or commercial, charging station):
http://green.autoblog.com/2010/10/14/ecotality-unveils-new-blink-dc-fast-charge-station-will-install/
It should probably be noted at this point that if you are planning to drive 600 miles in one day, that your second charge is not likely to be at home anyway, it’s going to be at a public/commercial charge point.
Then we get to the home options. At this time the Tesla HPWC (220V @ 70A = 15.4kW) is probably the best option (or the Clipper Creek CS-100) and would take about 6 hrs. Just a note: where I live the standard residential electrical service is 200A, and it has been for over a decade. Upgrades to 400A are optional at time of construction.
After that we get down to the lower power mobile charging systems, which will take longer, but the bottom line is that a 14 hr charge time for the 300 mile (90kWh) pack is not even remotely “the best-case scenario”, and if you are an honest reporter, you will admit it.
Chris H.
You’re turning my words upside-down, Chris. And, D, I am not going after Tesla, in particular.
The best-case scenario is having a high-power charger AND the home infrastructure to support it. In that case, IF Tesla (OR another maker) delivers a reasonably-sized battery for 300 miles, in the range of perhaps 90 – 110 kWh, charging times at home might be as low as 5 – 6 hours. Big ifs. I am on field assignment and dealing with a couple makers strong into battery power and have been asking if their data support the likelihood that a high-amperage system, like Tesla’s top charger is or could be supported widely. In frustration, everyone I asked said no. They don’t expect that to be anywhere near common, one reason their own planning is not aiming at long-range batteries anytime soon.
So, again, as to not be confused: under the most ideal circumstances, charging times of 5 -6 hours MAY be possible, and SOME buyers WILL have the technology and infrastructure in place. SOME others will be willing to spend to upgrade. MANY others, likely the majority of homeowners today, would not have the service in place. Even if they DID have 200A (at 110V), which is high for the average American home, that would need be shared around dryers, A/C, etc., and to use it with the largest Tesla charger would either require careful planning to power down other systems for those 5-6 hours or making a FURTHER upgrade in service.
Thus, for most homeowners without doing an expensive upgrade, a lower-powered circuit, in line with dryer lines or large range/ovens, are as much as you’ll get. Thus, at about 30 – 40% of what the big Tesla charger requires, charging times push into the 10, 15, even 20-hour range.
The reality is that for most folks, this is what they’d experience, not the best-case scenario of 5 – 6 hours.
As for the issue of targeting Tesla, I am simply referring to them because they have put themselves out front on a lot of issues, including long-range batteries. The maker has routinely tried to position best-case as the norm, rather than recognizing the broad range of issues. One of them is the challenge of taking a bold concept and executing it, whether a 2-speed gearbox or a 300-mile battery. They DO deserve kudos for their efforts, let me CLEARLY stress, but being transparent about failures, challenges and market realities would also be appreciated.
So, if you’re honest, Chris, you’ll correct your error and mis-perception. Attacking my integrity when you have simply misread my comments is inappropriate.
Paul E.
One other quick point: Your article seems to go after Tesla and the Model S when in your comments, it seems clear you mainly have issue with the state of the charging infrastructure. I personally would love to have a 300 mile pack, even if it took 10 hours to recharge from empty. This means I could go 120-150 miles on a trip and still have enough charge to make it home without having to recharge. Much better than the 40 miles on a Leaf.
Do we need a better charging infrastructure? Sure but we have to start somewhere and the more range on an EV the better. I’ve had my car for a short time but have already driven over 1,000 miles and my average charge time is about 90 min since I usually only drive 50 miles a day at most but have gone on one 160 mile trip.
Paul,
My statements regarding 200 Amp and 400 Amp service are based on empirical data gathered on the ground by electrical contractors. I will try to find more formalised data if it exists.
My 100A service could handle a 75 Amp Tesla charger just fine (mine is actually 70 Amp today). I always charge at night because the electricity is ‘cleanest’ and I rarely use the full charging rate because I sleep for more than 3.5 hours. However, If I found that I drove the Model S 300 miles everyday and wanted to charge it in 8 hours at home, then I think this is perfectly possible without any changes to my local power supply.
Obviously, if everyone in my neighbourhood wanted to fully charge a 300 mile Model S at the same time then the power company MAY need to upgrade some systems. I don’t see this as a major problem given the vast amount of cash that is currently being spent on gas… the electricity companies will find a way of making the investment.
Thanks, Kevin,
I am not as sanguine as you about what people have, nor whether a 100A service could handle a 75A charger comfortably for more than short blips at 2 AM…more importantly, your neighborhood utility will want to be making a lot more than the 4-cent super-off-peak electric rate people go on about before they invest billions in that infrastructure.
I live in Detroit where whole neighborhoods routinely lose power, often for days on end, because of the infrastructure. And we’re not unique. This blind passion people keep expressing about a major infrastructure upgrade is not reflective of the real world. I REALLY want to see this. I need to report on what is REALLY happening, and qualify any if/come projections.
Folks in this thread seem desperate to have me report based on their best-case projections (not even best-case today). I often did that in writing about the proposed switch to hydrogen and, early on, about electric propulsion. We need cautious, skeptical (as differentiated from patently critical) reporting, which is what I am trying to provide.
If folks don’t like the tone on this thread they should look at my overall battery car body of work before making some of the harsh accusations I have seen.
I appreciate the reasoned tone, Kevin, of your note and look forward to more data, should you come up with it.
Paul E.
Paul,
I’m simply reporting my reality today. I have a 100 Amp supply; I can charge my Roadster in 3.5 hours at 70 Amp; I could charge at 75 Amp if the vehicle supported it; I usually charge at 20-30 Amp because I’m rarely ’empty’ and that’s more than enough to recharge the car while I sleep.
Many of the people posting here are engineers with intimate, long term knowledge of the Roadster and batteries in general. They have tried to explain why your original premise regarding the Model S charge time is incorrect. If you truly believe that they are wrong then I think we’ve hit an impasse.
I’m not sure that I agree with your cautious and skeptical approach to solving the problems that the world faces today. Personally, I think that much more will be achieved by being bold and courageous, the sort of thing that humanity can be very good at.
I’m not advocating cautious and skeptical solutions. I’m saying we need be cautious and skeptical when told of “solutions.” Simply moving ahead in a bid to be bold and courageous will dig you in a hole, send you down a blind alley, or turn off those who wasted time and effort for no reason. Caution and skepticism raise the appropriate questions. Get the right answers and you can then move boldly and courageously. Do it the other way around and we’re right back where we were when we invaded Iraq, “knowing” the answers and not asking the question.
Paul E.
Paul: No one is asking you to report just the best case scenario, just a more balanced report. No one is trying to turn your words upside down: I’ll quote your article “The larger Model S, with its huge 300-mile battery, would, at best require about 14 hours to get back on the road – at best.”
When I read that, and the ‘at best’ part comes right after you’re talking about level II chargers, it’s pretty clear you mean 14 hours is the best you can do or at least that’s what everyone else posting here interpreted. You even write ‘at best’ twice in the same sentence to drive home the point. A level II charger can go up to 75A so that’s not a totally accurate statement as people have pointed out multiple times.
Why do you think they’re going to be some hugh weight penalty on the 300 mile pack? The 230 and 300 mile packs will have the same number of cells just different chemistries (also pointed out multiple times). Don’t you think Tesla will simply make the 300 mile pack as big as it needs to be to go 300 miles in range mode?
Again, it’s the language and tone of the article that many people have issue with. Take the headline for instance “Maker’s planned 300-mile battery pack may be effectively unusable – unless you have plenty of time to wait.” This would only really be a valid point if you’re referring to a small segment of car buyers who need to travel more than 250 miles in a day on a regular basis which is probably less than 10 percent of the population since a car with a 40 mile range covers over 60% of Americans. A 300 mile pack would be far from unusable.
You could easily rewrite this article to point out the lack of a great EV charging structure and that notifies potential EV buyers that they will need to plan ahead and charging may take a number of hours depending on what they can find.
Tesla has always been very honest about charging times and has been wonderful to work with. Anyone buying a car this expensive will not charge with a 110V outlet unless they need to in emergencies. Tesla is very upfront about the charging options and clearly steered me towards the high powered mobile connector that goes up to 40A.
What have people been trying to get you to believe on faith alone? Neither one of us has driven the Model S or had one at home I’m guessing so given that, people have clearly laid out their experiences with the Roadster (the closest car to compare to the 300 mile pack you’re worried about) and you don’t seem to believe them. I’m glad you’re pointing out issues with the charging infrastructure and making people think about wether or not an EV will suite their driving style but think the tone of your article could have been a little more balanced, that’s all.
D:
At this point, your issues are understood and I’ll agree to disagree but keep your points in mind. I hope you have, in turn, come to understand some of my concerns. See my response to Kevin’s latest note.
Paul E.
Thanks Paul for the discussion. Just curious but which parts of the discussion do you not agree with? I would appreciate you at least adding an addendum to your article with the parts you do agree and with what you’ve learned (at least with the points the Roadster owners have mentioned followed by your data and why you don’t agree). Many people will read your article and not the comments so there are a few points you’ve agreed were not accurate that should be corrected or amended. Thanks.
I still don’t understand the ‘effectively unusable’ comment in the title and was wondering if you could back that statement up with some facts. This will have more range than the Roadster and the Roadster if far from unusable.
Hi, D,
There IS an addendum…this thread.
Paul
Hi Paul,
“At this point, your issues are understood and I’ll agree to disagree but keep your points in mind.”
Paul, this is not a question like “which would you recommend, the steak or the fish?”. There isn’t room for an opinion – it’s just governed by very basic numbers.
You’ve made some pretty concrete – and demonstrably incorrect – statements that are the whole premise of the story. You’ve said yourself that “And that math is basic, not calculus” which on the whole is true (the tapering off of the charge near full excepted).
The charge time X can be closely approximated by dividing the pack capacity Y by the charge power Z. I don’t know about you, but we were taught that kind of math when we were 7 or 8.
Insisting that the charge time is “at best” 14 hours, when everyone here is telling you it is about 6, is at best sticking your head in the sand and at worst deliberately sensationalist. You are complaining that we are using a best case scenario (we aren’t), but you invited that with your own language in the story.
Furthermore, you know full well that the vast majority of lay-readers will stop at the headline, a few more will read the subtitle and still fewer will read the whole story. Only the fanatics like us will get this far down the comments. Most people will walk away with an incorrect impression of how long it takes to charge this car.
You may have some valid points in these comments about the resilience of US electricity grids and whether local transformers will have to be upgraded at some point, but (much as I’m sure Elon Musk would like otherwise) we are not going to see whole neighbourhoods with 300 mile Model Ss taking a full charges all night, every night. That scenario can be dealt with anyway, *but it has nothing to do with your story here* and is not going to become an issue for a good many years yet.
I’m sorry if you thought you had a scoop and we peed all over it. That’s the price for not checking the facts before you hit submit. You say you are pro-EV but you are not doing yourself any favours amongst the EV community by publishing a story based on incorrect facts and then refusing to acknowledge that when the community calls you out.
I understand but as people have pointed out, a few of your numbers are incorrect or are misleading. Most people don’t read the comments anyway and will stop at your article so an actual addendum or correction at the end of the article if you won’t change parts of the actual article (such as your 14 hour comment) is warranted. It would show that you’ve learned something from these comments and are willing to make a correction when warranted. No one is asking you to fluff up the article to make EVs sound like they are the solution for everyone but multiple people have pointed out why 14 hours is no where near the best you can do with recharging which I think you said you agree is correct. If you agree, then it should be corrected or amended in the article.
I’m still curious about what points people have made you don’t agree with?
If you goal was to get people to read the article with a sub-title like that then it’s worked but I still think ‘effectively unusable’ is misleading at best. At worst, it would be very inconvenient for long road trips and may not be the best car for that kind of person. At best, the 300 mile pack opens up the range for EVs even further. You’ve managed to make it sound like an EV with the biggest range is worse than the 100 mile range on the Leaf.
I guess you see nothing wrong with the facts in the article and I don’t think there is anything that I or more experienced EV owners can say or data we can offer that will make any difference. If you’re truly an EV advocate, I’m glad you’re pointing about the deficiencies in the charging grid and the potential problems of taking a large battery pack on a long trip but wish you’d change the ton of the article and fix the mistakes. You’re not doing EVs any good with such an article. Thanks.
Dave
Sorry, should read ‘change the tone of the article’. Anyway, thanks for the discussion.
Paul,
I think you’d have a lot more credibility if you wrote an addendum to your original story and didn’t rely on people trawling through this lengthy thread.
We are all trying to get the facts heard and I believe some serious questions have been raised regarding your claim that the 300 mile battery on the Model S is effectively unusable.
You DO raise some valid points that need thought and discussion. Why not break those out into other articles that we can debate? You have the attention of a large number of EV drivers and engineers with many years experience… why not learn from them and admit to your mistakes?
Kevin,
After 32 years as one of the most widely published, quoted and respected journalists, I think I have plenty of credibility, thank you. I have also validated my points in the story with enough sources that I feel nothing more than the discussion raised in the thread is necessary. If need be, I will revisit matters yet again in future posts. Frankly, any addendum would be as critical of questionable assertions as “corrections” of anything I have written.
This is where it will stand.
Thanks,
Paul E.
Can you list your sources telling you the 300 mile pack will take at least 14 hours to recharge at best? I don’t see how something as factually incorrect as this doesn’t need a “correction.” As a journalist of so many years, wouldn’t you want to correct an error in your reporting?
I’m sorry Paul, but a mistake is a mistake even if you’ve been a journalist for 32 years.
Sorry, Kevin, I don’t feel I erred. Any more than I expect you will be posting your error in any of your outlets, acknowledging that people will very likely not have the ultra-high-capacity chargers and, under most circumstances will be unlikely to be able to charge the Tesla Model S 300-mile model in anywhere near the 5-6 hour timeframe you like to claim. Most will be at 10, 15 hours and even longer.
End of debate. You’re welcome to continue posting, of course, but I have laid out my position and feel I am correct…and have been more than willing to allow questions to be raised and posted.
Thanks,
Paul A. Eisenstein
Publisher, TheDetroitBureau.com
Paul: Most people buying a $50,000 – maybe $80,000 EV are going to bother to at least install a 240V 30A to 50A circuit in their garage (something any electrician can do for not a lot of money). A 244 mile Roadster can recharge from empty on a 30A outlet in 10 hours and a 50A in 6.5 hours.
How does the math work out that it will be 10, 15 hours or even longer then? Again, installing a NEMA 14-50R outlet in your garage is not something out of the ordinary, especially for someone buying a luxury EV. You still haven’t shown to us how your ’14 hours at best’ comment holds up. Yes, if you assume everyone who buys a $50K+ car will charge on a 110V outlet, you got us and we must be deluding ourselves.
Really, I don’t think you understand the driving patterns of most EV drivers. Most people don’t drive 150+ miles in a day so even charging on a 30A circuit (after driving 150 miles on a 300 mile pack) would charge full in maybe 7 hours. Easily done overnight.
Again, if your main point was that a fast DC charging infrastructure isn’t built out yet and that taking long road-trips in an EV will require some planning and patience then yes, you have a valid point. But your article comes across as very bias and not totally accurate.
Under ‘most circumstances’, people will be charging at home and not on the road. If you’re talking about long road-trips as I stated, then you have more of a point but 95% of all the driving I’ve ever done has been less than 100 miles in a day. Easily within the reach of a 300 mile pack and plenty of time to recharge at home.
Please detail how you come to your 10-15 hour recharge times for most people. Are you assuming that people will recharge from empty every single day on a 110V outlet?
Paul,
I see you’ve made some changes but you’ve also introduced some other mistakes:
“Opting for a Level II 220-volt charger will typically trim the charge time down by at least half. Depending on the amperage of the charging system, that can bring charging times down significantly. Ford’s 7.5-amp Level II charger for the upcoming Focus Electric is expected to trim times down to just 3.5 hours, about half the time required to recharge Leaf using its lower-amperage system.”
Ford’s charger may be 7.5 kW but it sure as hell isn’t 7.5 A.
The problem that I and clearly many others have is with this:
“The larger Model S, with its huge 300-mile battery, would, at best require about 14 hours to get back on the road – at best. A lower-amperage charger would keep the sedan tethered for a day or more. That is, unless an owner were ready to head out on only a partial charge. But, at that point, what would justify paying the huge price premium for the extra kilowatt-hours?”
We’ve shown unequivocally that your use of the phrase “at best” in this paragraph is wrong. You’ve resorted to arguments about people having to upgrade their domestic electricity service, which may or may not be true on a case by case basis, but it doesn’t take away from the fact that 14 hours is not the “at best” scenario that someone buying a Model S can expect. In fact, it’s not even the second best because, as the others have pointed out, with a cheap NEMA 14-50 one can still comfortably charge the car in around 9 hours.
You are getting feedback from multiple experienced Roadster drivers. I’d take that as a good thing. All we are asking for is the flawed 14 hour premise to be corrected.
Sorry, D, but 1) I’ve made no changes to the story, and induced no errors, nor “corrections.” Secondly, I stand by the 14 hours. Barring a massive shift to higher-amperage chargers a best-case, 70A scenario is an exception, not a rule. Tesla has declined to provide me with information indicating what percentage have the high-amp chargers, nor will they indicate what percentage have such chargers and actually can or do use them at such high power. What I am being advised is that the current crop of public chargers aren’t … and those coming likely won’t … be anywhere near 70A. Even some who have contributed to this and other threads on TDB indicate they do not charge Roadsters at that power level…or did not opt for such chargers. The Roadster battery is, of course, smaller than the battery for the hugely heavier Model S. And Tesla’s “official” PR statement to me does not support the power consumption of the smaller battery (300 wH/mile) in a 160-mile version of the car, never mind what will be needed with the even heavier 300 mile model … which continues to suggest a larger battery will be needed than you and others continue to try to state. The data I work with comes from Mr. Rawlinson, and is backed by other sources, so I believe I am solidly on target.
At best, under the most ideal conditions, charging from home, using the highest-power charger at its max setting, after having (in most situations) massively upgraded the power capabilities of the average home, you may see a small to modest number of owners being able to charge in 5, 6, maybe 7 hours, but that also is only in the home. At any even modestly lower setting using the high-end charger, charging times will run 10, 14, even longer. A person using any of the many other chargers now on the market will likely see 14, 15 hours even longer. Charging in public will be a day-long affair, barring the use of a 440V 3-phase. For the vast, vast customer base, only under absolutely ideal circumstances at home will the numbers you propose be a reality.
Significantly, I have received no request to revise the copy from Tesla. That suggests they are also aware that when migrating from the limited, high-dollar customer of the Roadster crowd, who generally could and would go at 70A, they will likely not see folks go anywhere near 70A capability with a much more mainstream Model S. For them, again, except for under ideal conditions, likely limited to a very few, my numbers could even be optimistic. Indeed, the reason I wrote the story was having precisely this scenario expressed by several different Tesla folks.
Sorry, D, et al. No change. This thread allows readers to make up their own mind.
At this point I consider the discussion complete. I will not be commenting further, as we’re just going in circles.
Paul E.
So you do admit that 14 hours isn’t an “at best” scenario then?
As was pointed out, installing a 50A outlet in your garage is not some ‘high-end charger’ but basically having an electrician install a dryer outlet in your garage. Almost any modern home would not need to be ‘massively upgraded’ for such a system. At least a 50A outlet is something I’m guessing 90%+ of EV buyings opting for a $50,000+ car would choose. If spending $1000 is too much to upgrade their house for a $50,000+ EV, then maybe it’s not the car for them. Very simple.
The vast exception is DC fast charger at probably 90 mins to 2 hours. A very uncommon option would be a 70A charger at probably 6 hours (assuming your 106kWh pack size which is probably 15kWh too big). A more common option would be a 30 or 50A outlet which would charge the car in yes your 10-14 hours but something that’s common is not ‘at best’.
I would think actual experiences of actual Roadster owners would count for something to you. This shows easily that you are misleading people with your charge times and always implying that you’re charging from empty which you almost never are.
Exactly, almost none of the Roadster owners with the 70A chargers actually charge at 70A. Most of them charge at 32-40A which was also previously stated. This means it really isn’t needed for most Roadster owners. A bigger battery pack is actually a good thing which you seem to miss. Going from a 160 to 300 mile pack basically doubles the range you can drive without having to recharge. Something I would think would be a good thing. You don’t use the 300 mile range every day so even if you’re not able to do a complete charge on a 50A outlet, you can still add about 200 miles in range in 6 hours. Do you not believe these numbers? You’re also using numbers off of chargers that exist now, not in mid 2012.
Why don’t you at least qualify your 14 hour statement? It’s very open ended and misleading. Using a 30A outlet, yes it could take maybe 14 hours but that’s assuming you’re always charging from near empty. Your use of ‘at best’ twice in the same sentence gives away your intentions in the article along with your ‘effectively useless’ comment in the title. You say you stand by your 14 hour comment but don’t indicate what the charging scenario is or what amp charger you’re assuming.
It’s sad to me a journalist of your many years feels the need to write such a biased article and then refuses to make corrections as necessary. You never answered the question as to why a 300 mile EV is ‘effectively unusable’. Roadster owners have been driving the 244 mile pack for years and have found it more than adequate. It’s safe to say that no amount of evidence will change your mind so I guess this is a closed issue in your mind. Thanks.