Should we see an improved battery soon? If not, is it overdue?

Should we see an improved battery soon? If not, is it overdue?

The Model S has been in production for over 1 year. It's battery system was designed at least 2 years ago. Nothing new in terms of performance or capacity has been released since then. It's unlikely that there have been no improvements to the current battery system, the Panasonic 18650 cell or that another superior cell is not available at the same or a lower price. I've read that battery prices and technology improve around 8% per year. While I don't doubt that this is among the many things Tesla is working on, it hasn't even been hinted at. Shouldn't we be seeing something before too long? If not, why not?

I know there are many EE's out there as well as others that are knowledgeable about this topic, would appreciate your thoughts. TIA.

Blueshift | 2013年9月11日

> I've read that battery prices and technology improve around 8% per year

I've only seen that mentioned in Tesla literature (around 2008 I believe). Does anyone have an external reference? Seems overly optimistic to me.

I don't think my cell phone battery life has been improving that quickly. :-)

negarholger | 2013年9月11日

The 8% is averaged - improvements will only happen in steps. Elon said to expect the next step in 3-4 years - that would be the Gen3 time frame.
The last step was from Roadster 2.1 Ah cell to MS 3.1 Ah cell - about 40% over 5 year agrees with the 8% per year estimate.

jat | 2013年9月11日

The 8% is also price/capacity -- so Tesla is probably paying less for the cells, but as long as they have more demand than they can fill they have no incentive to pass those savings along (and instead they have been raising prices).

Dramsey | 2013年9月11日

I'd be surprised if we see anything new for the Mod S in terms of battery any time soon. After all, Tesla's quoting the exact same capacities for the Mod X and that's, what, 18 months out?

Docrob | 2013年9月11日

Something that was never due can not be overdue. Battery upgrades were always specifically advised by Tesla NOT to rely on. They said buy the battery you need because they would not guaranteee upgrades. I fully expect them to be available at some point but certainly not every 2nd year. Perhaps at most every 5-8 years, probably more like 10. This allows you to replace an ageing battery not just with like but with better.

Brian H | 2013年9月11日

The first couple of years ('08-'10), I caclulated it was more like 17%/yr., for Panasonic's cells.

oildeathspiral | 2013年9月12日


Good point that it's an average. On your second point, and it kind of goes to what Docrob said, I recall Elon talking about a remake of the Model S in regards to styling etc. after a few years but nothing specifically about batteries.

Maybe any improvements being realized by Tesla are in the form of lower prices and therefore increased margins or fewer cells with the same net capacity which would also lower the car's weight, improving performance and range.

The reason for the original post is because I always want to see continuing improvement in EVs in general and Tesla's lead over everyone in particular. Guess I'll have to wait longer.

oildeathspiral | 2013年9月12日

Brian H

Where did you get the data for your calcs? Any suggestions on where I could keep up with improvements? Thanks.

Out4aDuck | 2013年9月12日

It's really tough to get new battery technology into production. In addition to cost and energy density, batteries have dozens of other attributes which must be considered. Unfortunately when you improve one attribute, it's usually at the expense of other attributes. It seems that every week you see a press release about some significant new battery technology. But only rarely does it find its way to the consumer market. An example is the Panasonic 4.0 Ah cells. Correct me if I'm wrong - although they were announced a couple of years ago, I'm not aware of any consumer applications.

I'm assuming that for the Model E to meet its range and price targets, a revolutionary improvement in battery technology will have to be made. I just don't see that happening in the next five years.

mrrjm | 2013年9月12日

Has anyone thought about this...Go to a tesla service center and do a battery swap when they are available. And it's done in 90 seconds.

Pungoteague_Dave | 2013年9月13日

mrrjm, don't fall for the battery swap myth. Not gonna happen. Volkerize for more of my analysis on why, but TM just replaced my battery at 7,600 miles, standard work order is 3 hours, actually takes 5, requires replacing and bleeding gallons of ethylene glycol, multiple manual hand-hook ups that can't be automated, at least on the cars delivered so far, removing panels that attach to the battery, replacing and torquing and hand checking single-use bolts, etc. Further, the economic model is nuts compared to supercharging, would require big indoor facilities and staffing a la Jiffy Lube - it exists as a concept for marketing and battery credits, nothing more.

bonaire | 2013年9月13日

P_D - why did your battery get replaced?

celtrog | 2013年9月13日

There is new battery technology right around the corner....
solid sulfur battery with 4x the capacity of lithium ion...
a 1200 mile Tesla could be on the horizon and with the death of the ICE......
not as far fetched as one might think! check it out...

ThorensP | 2013年9月13日

Cool article. I didn't see anything about charging speed. Do you know how fast the lithium sulfur batteries charge compared to LI?

Andrzej1 | 2013年9月13日


At present, Oxis lithium-sulphur batteries take about 7 hours for a full recharge, although they say they will get this down to 4 hours in the next year. Achieving fast charging is a long term goal. Another problem at present is limited charge cycles which would not allow EV manufacturers to offer a 8 year battery warranty. Nonetheless Oxis plans on beginning commercial production next year. See here,

For an overview of lithium-sulphur battery developments in the last few years see here,

It sure would be nice if DoE's $120 million grant program was able to meet its goal of making batteries five times more powerful and 80% cheaper within five years. This would require an average 38% annual improvement in battery energy-density which would be truly remarkable given that annual improvements have generally been at 20% or less.

jat | 2013年9月13日

@PD - yep, battery swaps are totally fake, that's why they demo'd it being automated in front of a live audience. You can argue any number of economic reasons why they aren't going to be widespread, but saying they can't be done in less than hours is silly. After all, they are installed by robots in the factory, so why wouldn't you think those same robots can do it elsewhere?

People also thought building a nationwide supercharger network that could get 200mi charge in under 30 minutes was fantasy and could never happen economically either.

Andrzej1 | 2013年9月16日


“Any suggestions on where I could keep up with improvements?”

If you live in the Detroit area you may want to consider attending the Electric & Hybrid Vehicle Technology Expo/The Battery Show running Sept. 17-19 at the Suburban Collection Showplace. Some of the leading edge battery players such as Argonne National Laboratories and California Lithium Battery will be displaying here. For a full list of exhibitors see here, .

In lithium-ion technology, CalBattery at present has one of the highest reported energy densities at 525 Wh/kg. See here, .

Registration is here, .

oildeathspiral | 2013年9月17日

Thanks Andrzej1

Have family in the Detroit area but live in CA so while the show you suggested is out I will be attending the altcarexpo in Santa Monica. Been going since the Volt was only on the drawing board-now I own one. It's also great to see how much stronger the auto makers are compared to when I went in 2008, '09 and '10. Exhibits are much more elaborate, many, many more cars to drive but more importantly they now have plenty of capital and incentive (Tesla) to expand and improve their EV offerings.

Any opinion on the technology behind these Tesla patents?

SUN 2 DRV | 2013年9月17日

FWIW At the most recent analyst briefing, Elon was asked what battery improvements Tesla was working in the near term. Elon said there's no changes coming immediately at the cell level, but that they are working on optimizing things at the pack level.

I wonder if those are just manufacturing improvements or whether that effort might show up as actual capacity or performance improvements? I suppose one could even consider implementing a hybrid battery as an effort at the pack level.....

Brian H | 2013年9月17日

Elon has sworn never to put a putt-putt in any of his cars.

petochok | 2013年9月17日

I think joehuber means hybrid battery, not hybrid drivetrain.

AmpedRealtor | 2013年9月17日

@ joehuber - Upgrading the Model S to longer range one year into production would probably tick off a lot of owners, especially if that range improvement came at no additional cost on the high end (i.e., today's 60 becomes an 85, today's 85 becomes a 110, etc). Also, there is no competition even at today's range levels, so it's somewhat premature to discuss "what's next" when the competition is still catching up to "what is". Also, Gen III is targeted to have a 200 mile range. I really don't think a higher capacity battery is in the cards. Tesla is pushing its resources into shipping Model X, which has the same battery capacities as Model S, and Gen III which will also not have longer range.

While I would love a 500 mile or larger battery, I just think it's wishful thinking given what Tesla has in the vehicle pipeline.

celtrog | 2013年9月17日

As technology improves IMHO Tesla will not hesitate for a second to use it...
Anything otherwise would be counter to its entire being as a company and Elon's history..

As it has been said: The best predictor of future performance is past performance.....

When has Elon NOT used the best technology available?

Someday we will wistfully recall that quaint Tesla MOdel S that could ONLY go 300 miles and how we ever put up with that...

Not too long from now

AmpedRealtor | 2013年9月17日

Let's look at the Roadster history, hasn't that been in production for a while and has its battery changed or have upgrades been offered? The only time Tesla has improved and expanded the battery was with a new platform, i.e., Model S. So if we are to look at their history, the same will hold true here.

bent | 2013年9月17日

AmpedRealtor wrote:
"Let's look at the Roadster history, hasn't that been in production for a while and has its battery changed or have upgrades been offered? The only time Tesla has improved and expanded the battery was with a new platform, i.e., Model S. So if we are to look at their history, the same will hold true here."

The Roadster is a "dead" product line though, and was only ever intended for a small production run. In essence it's a concept car that saw limited production. You can't really expect a lot in the way of running updates for such a model once it's no longer being built.

I think the earliest we are ever going to see a different battery pack for the Roadster is 2016 when the early builds may start needing a replacement pack, they're really not needed before that anyway. The Model S though, still being in production and likely to remain so for a good many years yet, may well see a new pack long before that: Even if existing cars may not need replacements new cars can benefit from a new pack.

Brian H | 2013年9月17日

Agree with AR; TM/EM go with proven best-of-breed, not newest.

Andrzej1 | 2013年9月18日


You're welcome oildeathspiral.

As for the patents themselves, I think it unlikely that this type of hybrid battery will enjoy any long-term economic success if it is ever introduced commercially. It is premised on the idea that a rechargeable metal-air battery would have a limited number of cycles and so would only be engaged in the event of one taking an extended trip. However rechargeable metal-air batteries are far from commercialization and when they do come to market I would expect them to have good power density and a sufficient number of charge cycles for EV manufacturers to offer an 8 year battery warranty making this whole patent obsolete. Moreover as I mentioned above, lithium-sulphur has been on quite a ride lately with a flurry of papers being released over the the last 12 months. Oxis is planning on releasing a commercial version next year and I expect a viable replacement for lithium-ion technology in vehicle applications 5 years from now.

The 40% gain in range with this hybrid battery system cited by the analyst in the article you reference will be achieved by both Envia and CalBattery using lithium-ion technology. Look to GM to introduce an Envia based EV in the coming years. They recently announced the goal of a commercial introduction of an EV with a 200 mile range for a $30k price tag. Elon tweeted earlier this evening that he is happy to hear this and hopes others follow.