Model S 45 min. Fastcharge

Now that Tesla has broken news that each add'l 70 mile range increase over base will cost $10K, I know I'm wondering where that leaves those of us who will periodically want to take our EVs for longer trips. I would hope to someday drive mine from NJ to Charlotte, N.C. - a distance of about 600 miles. I think a big factor in whether I'd get 160, 230 or 300 would be the availability of locations where this "Fastcharge" would be available. Does anyone know if there are plans for Fastcharge to become available at the usual interstate fuel and food stops? Is 45 min. recharge time for a 160 battery pack or for any of the three? Does BetterPlace plan to put these type of Fastcharge hardware at Interstate fuel stations? If you could reserve a charging spot in advance (from the 17 " info screen of course!) and recharge in 40 min. while having coffee or a meal, the 230 pack might do the job.

Bobfitz, no one knows the answers to your questions yet. It is a chicken or the egg situation. I think it is a matter of when, not if the things you suggest occur. I am considering investing/subsidizing a few fast charge stations. Perhaps other early adopters will do the same.

An app for smart phones or the Tesla navigation feature will be valuable to advise locations of fast charges, their condition, and capacities. I expect reservations will also be available for some.

I honestly believe that by the time there is a nationwide network of 45min charge stations for the Model S, we will have seen significant improvements in battery technology, such that a 400mi to 500mi range is possible. Once you hit a 500mi range, you won't need a 480V fast charge. For very long trips, you will drive for 10 hours (500mi), then charge overnight at your hotel, while you sleep.

Honestly, today, probably about 90% of all commuters can make due with the 160mi battery pack. That means they are behind the wheel from 0.5 to 2 hours each day (M-F). If a family makes a lot of long distance car trips, either they will have a second vehicle (for that), or a plug-in electric car is not a realistic choice for them right now.

That 400 miles comes sooner than you might expect. Panasonic is already testing 4Ah batteries, and 300 mile is achieved using 3.1Ah batteries. That is 400 miles right there.

That is nowhere close to what those batteries could be, even with 4Ah batteries it is still only about 320Wh/kg, and there are lab prototypes for batteries over 400Wh/kg. With them comes 500mile ranges. After that it starts to just get lighter and cheaper, maybe 600 miles for range is the peak, because that means 10 hour driving with 60mph average speed, with fast charging stations on a way you could drive all you want using just lunch break to charge and good night sleep to charge again.

Problem with 90% commuting calculation is that even that 90% of driving is made with short distances 90% of drivers still need much longer range occasionally, and public transportation just can't be used for every trip (actually in here they have managed to raise train ticket prices so high that driving a car is cheaper, and you sometimes get plane tickets cheaper than train for some trips. You just want to use car when public annoyances are so expensive).

As long as you can provide the necesary juice (around 90 kilowatts) you should be able to recharge at that speed for the 300 mile pack. The cells are being charged in parallel, so extra cells won't be an obstacle to the others getting sufficient juice, as I understand it.
The issue with mileage, as we all saw this week when the prices
were announced, is neither battery density nor their ability to fast charge - it's their cost that prevents 400 miles ranges from being a reality. And I strongly object to the notion that batteries need to be rechargeable any faster than one hour for pleasant long distance travelling. That's stopping for a meal every 4 or 5 hours,something practically everyone does anyway. I also notice that the Chevy Volt has a driving range barely more than 300 miles, at best.

In Norway we have > 2000 free charging stations with 220V 16A or 32A? Where I live, the local powercompany has made Quick charger with 550V 110A !!! Is the Model S made for this?


550V * 110A = 60.5kW

45min charging for 80% of pack. Pack size ~90kWh. (0.8 * 90)/0.75 = 96kW.

That's not powerful enough :-)

I have no idea about connector compatibility though.


the Tesla web site lists numbers that cannot be combined in one Model S car, e.g. "base price $50k" and "300 miles of range".
One more: The subject of battery pack size vs. acceleration has been discussed at large, but we just don't know if they all will meet 5.6s - or if only the largest or the lightest pack will be able to do this.
Similar thing is possible with the 45min quick charge. There were 480V mentioned as quick charging voltage. So the 96kW calculated above results in 200 Amps. If the fast charge port is limited to 100Amps, the 45 minutes would be correct only for the 160 mile pack.
Again, the numbers are not wrong, instead they cite best-case scenarios that cannot be combined.

I'm pretty sure batteries in 300mile version can be charged as fast if not faster than 160 mile version, it just requires different electronics to handle them.

As you said you can't tell if the max acceleration is with 300 mile version, but you can't say if it is in 160 mile version either, less batteries = less available power to draw from pack. 230 mile and 300 mile battery packs should weight the same, so if one of them gets the max acceleration, so does the other. It is the question of weight vs power.

However if we assume 90kWh battery for 300 mile version and cut that to half 45kWh and use Panasonic 3.1Ah batteries weight between battery packs doesn't change that much. Weight in that would be about 184kg then 230 mile version and 300 mile versions weight (batteries alone) about 276 kg. That's 92 kg, and only about 5% of the entire car weight (assuming 4000lbs/1814kg curb weight). I'm pretty confident that even if the fastest pack would be the 160 mile version they all hit that 5.6s barrier.

For that same calculation for 160 mile version (half the capacity) max power would be 48kW. In that case that would be enough, but it still remains mystery if the connection is compatible with Model S charging port.

I would guess that any accel or recharge time figures mentioned
without specifying battery pack size would apply to all versions.
I don't know how the recharging power is applied, whether individually to each cell, or to a string. Regardless, adding another bunch of cells (or strings) won't mean anything if there is enough power to maintain power levels at the point of recharge. The cells/strings would all be charging in parallel and as long as that parallelism is maintained, you can recharge a battery 100 times larger at the same speed. If parallelism is at the cell level, then the speed will equal the speed at which a single cell can be recharged, a guide when future cell technologies become available. I don't know the reason why all battery packs (apparently) don't allow recharges at the cell level (probably cost, would be my guess). The Chevy Volt takes practically forever to recharge their small 16kWhr battery, of which (at most) only 9 kWhrs are required to fully recharge. If the 45 minutes refers to the 300 mile pack, then the Tesla can recharge at a per mile/per hour rate that is almost 30 times faster than the fastest Volt rate. Makes little sense to me. Certainly LG and GM aren't that dumb. Well, I know LG isn't that dumb. And you can't call the Volt cheap, either, considering what you get.

Usually battery max recharge speed is close to its max discharge speed, and power density is higher than energy density, so I think 45 minutes to 80% charge is not even close to how fast those batteries really could recharge given enough power (after all you draw out of them more than 200kW). I think that 45min limit is determined by onboard charger capabilities, not the batteries.

Another limit is the AC system capacity. With 90% charging efficiency, the AC would have to deal with 9.6kW of heat from PEM, ESS, and AC compressor. Not sure if this is guaranteed in warm conditions, or at any temperature at all.

Will spare batteries for quick battery exchanges be available? I'd like to set up secure charging/changing areas at my desination points for my commuting needs.

Without heavy-weight robotics you can't "quick swap batteries" for Model S. That thing weights something like 500kg at least.

Maybe he's working out? ;)

Timo is right about batteries not being the delimiting factor. Todays AGM batteries can take a 2000AMP charge if you can find something that big to charge it up with. In fact, when AGMs first into vehicles the alternators were blowing out and burning up because the battery would draw the maximum possible AMP charge and of course the alternator would try to keep up, right up it's death. Electric upgrades were put in place so the alternators didn't try to output more than they safely can.

As for 45min charge times, its all about the AMPs. You need to pull about 400AMPs, or more. A 400amp breaker will have a draw charge of about 320amps, which should charge a 300mile pack in about 45mins. So to safely setup a 400amp circuit at home (which has probably never been done), you'll probably need a 480Volt setup to deliver that power reliably.

That means you'l need a new box, wires 1/2 as thick as your arm, the charger from Tesla and a really good electrician to put it in properly. I can't imagine getting this done at home for less than $10k. I'd hope there is a "dial in" switch so I can select the amps (from 40-400) so that i'm not always putting max stress on my car and shortening my battery life.

Timo, How do you figure changing this battery would be difficult? I Change 6000 lb forklift batteries with handjacks with no issues. The whole car with battery weighs just over 4,000.

A staff member at the Tesla store estimated a Model S battery swap could be executed in about 10 minutes at a properly equipped swap station. Like so many things they tell me, I have no idea how much is speculative vs. scientific basis though.

It is possible, but not without some sort of mechanical lift, and because it is underneath of the car and very large (dimensions, not just weight) you need to lift the car before removing the battery, and lift the battery too while lifting the car.

It is also connected to frame from several points, is waterproof, has cooling plumbings and high-voltage cables connected etc. Not easily done procedure and not for home tinkerers.

True about it not being easy for tinkerers. Everywhere I've seen Tesla folks talk about battery changes they've said it can be done in under 5min. This is the first time I've heard a 10min estimate. They never really explained the circumstances surrounding that lightning fast swap though.

I assume it is with robotics like what they use in Project Better Place. You drive the car in position where battery changing robot can access the underneath of the car, unscrew the 10-20 bolts attaching the battery to frame, remove the battery and place another in its place in seconds and then screw those bolts back (and in between detach/attach cables and cooling).

For humans, especially for single human, that operation would probably take longer than it takes to charge the battery fully or equipment to do that would cost more than a (really) fast charger.

Looks like Nissan came up with a charger that can give you a full charge in 10min. It looks like it won't be available for 7-10years, but maybe we'll be able to ride this train too, ya?

A full charge for a Leaf doesn't amount to much. Even so, you still trade power for time; i.e., you need heavy-duty charge points and cables to deliver that many kwh that fast.

"And I strongly object to the notion that batteries need to be rechargeable any faster than one hour for pleasant long distance travelling. That's stopping for a meal every 4 or 5 hours,something practically everyone does anyway. I also notice that the Chevy Volt has a driving range barely more than 300 miles, at best."

First, I strongly object to using the Volt (or any other Chevrolet) for comparison to Tesla. We are supposedly discussing what could potentially be the overall best cars ever created, soon as they get the range thing dealt with...not ordinary cars for the masses like Chevys.

Second, I strongly object to people who believe it their place to decide what others "NEED". Whether it be income, car size, house size, boats, swimming pools or electric cars. Busy people with active lives don't HAVE an hour to twiddle their thumbs. We're used to pumping the gas in 4 minutes, and we're back on the go. We have somewhere to be. For electric cars to supplant traditional ones, THEY need to get with the program. We don't. What if we don't HAVE an hour, maybe only a half hour or we're late for the presentation, lose our job and have to sell the Tesla? What if we have a modern life with other things to do but sit around and wait for the stupid CAR to recharge?

I'm in favor of individual freedom of choice. What if it's our personal CHOICE to seek ways to extend the driving range to 800 or 1000 miles, or to speed up the recharge time to ten minutes? What if we choose not to "stop for a meal every 4 hours" as you like to do, and we eat on the go in the car or choose not to eat? Who are you or anyone else to "strongly object" to that? It's a rhetorical question; the answer is nobody.

Sorry for a first post to be of a little strong nature but I strongly object to being nannied. Tell me the short recharge time scientifically cannot be done, that it's physically impossible; just don't try to tell me I don't "NEED" it. I alone will always be the one to decide what my family needs--as any person of means to be seriously considering high-end luxury cars will attest.

That said, I absolutely concur that the Tesla S is one of the most beautiful sedans on the road, right up there with Maserati Quattroporte, Fisker Karma and my 2006 Infiniti M45, the flagship of Japan which the Tesla extremely closely resembles in shape. Incredibly, the S with the rear seats folded down has the exact same cargo space as my Mitsubishi Lancer Sportwagon, at over 60 cu. ft., which is HUGE. A massive advantage over the space in the Infiniti or any of the Mercedes sedans I've owned. The Tesla S will be my next car, IF AND ONLY IF they get this serious driving range/recharging problem solved. We live in coastal Florida, and if we have to pack up and flee to Georgia from a hurricane, we deserve the same driving range and refueling time that people are getting in their old rusty Chevys.

(apologies if this appears more than once, the software isn't posting it to the forum so I had to re-submit)

@hyjyljyj: Okay, with current technology, it can't be done. Considerations: Laws of physics, material costs, safety, long term battery life.

I'm not going to say that you NEED anything. However I will say that you don't DESERVE anything. I'm not being antagonistic. But you're coming off as self-entitled either because you feel that way or you just made a bad choice in words.

hyjyljyj, you leave me wondering where you took the time to type that lengthy post... Ramon123 was talking about pleasant long distance traveling. You are talking about racing through your life. Seems unpleasant to me, and I wouldn't call that traveling, but that's subjective of course.

And that should explain to all you Europeans as to why us Americans are so fascinated with the number of cupholders in our cars

Self-important elitist pomposity to the extreme. Name-dropping his cars, implying how important he is. Doesn't deserve this car.


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