Is it fair to say GM will eat a lot of money on battery warranty work?

This is what I would expect of GM. While I don't think the Volt is a good fit for most people, my biggest reason for avoiding it, and counseling people to avoid it, is GM itself. I think that Toyota makes an effort to build the best cars they can, with the idea that reliable cars bring customers back. I think GM does everything it can to maximize short-term profits, and the customer be damned, with the idea that the people in charge can collect their obscene salaries, and collect on their golden parachutes even when the company goes bankrupt because people don't trust their cars.

I don't hate the Volt, but I do think that GM is a dishonest and unscrupulous company, and I would not trust them as far as I could throw a Volt.

 

I hate to be that guy but Lyle's post at gm-volt is not a source. Do you have a quote from GM?

It may very well do exactly that, but I've not encountered an actual definitive quote. As a user, I prefer that approach myself. *shrug*

 

Your $110,000 Tesla Roadster has a 3 year battery warranty, Nissan requests users not use the full pack/won't commit to warranty capacity/cheaped out on TMS and GM is the bad guy? You're commitment to hating GM is impressive. I will give you credit for that. If they really do expand pack usage as it ages (so far, only "confirmed" by a Lyle post at gm-volt), that seems like a perfectly reasonable design choice to me, especially if it fits within their declared 10yr/150k mile target.

What is the Model S battery warranty going to be?

Are you suggesting that it's not quite as simple as LiMn2O4 vs LiFePO4? There's more subtlety than that? No way.

 

Well I just sent an email to Chevy asking them this question. Hopefully I will get more than an email back with snazzy photos and the spec sheet and an actual answer will appear.

 

Of course it is not that simple. But you can dress up a turd and it is still a turd.

Putting playing cards in the spokes does not a Bugatti make. It does make it louder though...

 

Mike, can you get the motor to come on in your Volt before hitting ~20% SoC? Seems like the person putting on a lot of miles would maybe want limit DoD to 30% or so -- maybe increasing the total cycle life by a factor of two.

Comparing Volt to Leaf and Tesla re: battery lifetime is somewhat unfair, because Volt drivers can (and probably most do) drain the battery completely on a daily basis, while Leaf/Tesla types are far less likely to deep cycle their packs due to risk of being stranded.

 

It depends on how the battery is engineered, i.e high power vs. high energy. NiMh battery in the regular Prius has very high power and it has been rock solid. High power battery pack generally weight more, which is why PiP pack has higher weight/kWh ratio than Volt or Leaf.

The battery chemistry in Volt and Leaf are outdated. PiP should be getting the next generation cells (NCA based) from Pansonic.

Several other companies have reportedly developed their own versions of lithium NCM batteries, including Panasonic, International Battery, and Molicel. Both the General Motors' Volt and Nissan's Leaf use dual-composition battery cathodes that combine manganese spinel (a safe though lower-energy-density material) with NCM compounds that boost the former’s performance.

Lithium NCM chemistry is increasingly seen as a preferred solution for battery systems for smaller city-focused EVs, urban delivery EVs, and plug-in hybrid vehicles over the next three to five years, according to Axeon.

The company’s latest cells are among the first of a new “class of lithium-ion chemistries based on mixed metal oxides,†Paterson explained. Other even more capable mixed metal oxide battery formulations, such as nickel cobalt aluminum and layered/layered spinel composite batteries, should arrive during the next several years, he said. The latter type features two chemical oxides in a sandwich structure on the same particle.​

Source

 

Not a volt owner, but here is some information about volt and batteries. You can use mountain mode to turn the engine on with a higher state of charge. This is not likely to increase battery life, gm has it in a reasonable state of charge when moving and years will take more of a toll. Around 40% SOC is the best level for generic lithium sitting, you could find out what the level of the volt battery is and just partially charge it to this level if the car is sitting for a long period of time.

Completely fair response to daniel, since the higher level charge will likely degrade batteries faster. The leaf and tesla do not need to be charged up to full and we have no data. If they are getting charged all the way up this will likely decrease their battery life and they have less of a warranty.

 

I think your 40% comes from the "old school" Lithium-Ion and Lithium-Polymer cells found in old laptops and phones. The phosphates and other oxide type cells don't have this 40% level. I do remember reading about a number in that range back in the day.

 

That is the generic number as I said. If you have a good number for volt, leaf, and tesla, I would love to here it. In any case the number is less than 90% from the car manufactures recomendations.

 

You can only put it in Mountain Mode, which triggers the ICE at 45%. Seems like that's the last thing a person driving lots of miles would want to do.

Maybe in the abstract but installed in a car you're driving, it's perfectly fair. GM made a design decision (smaller battery) that results in more charge cycles. The larger batteries in Leafs and Tesla products should, for a given drive cycle, lead to longer battery life. Nissan seems convinced(ish) that they can get by w/o full thermal management and exposing more of the pack. The wider band wouldn't affect me but someone driving 75miles/day may regret it some day.

Realistically, it will be years before we know. In the wild, the outlier Tesla drivers have, what?, 30k miles on their roadsters?

 

Did you buy or lease your Volt? Anyone here actually purchased a Volt?

 

We have a number for the Volt because of its chemistry it is around the 20% mark. Similarly the A123 LiFePO4 cells in the Tesla have a similar 20% mark. I haven't followed the Leaf at all so I have no clue what they use. But I would be surprised if they ventured away from industry standard lithium so it is probably close to 20% as well.

 

Ah now I get your objection, that's not what I meant. 40% is the generic number for longest shelf life for the battery, they keep better if they are not hot, nor full, nor empty.

20% seems like the number that seems like a good lower bound for charge/discharge range while keeping good shelf life.

 

The Tesla's 3-year warranty is against defects. There is no warranty for range. However, with a range of 245 miles, the only way I'm ever going to be stranded is if the car breaks down. Tesla thinks the battery pack will be at 80% capacity in about 7 years. That's a range of 196 miles. After another 7 years it will likely be at around 150 miles, which is still farther than I'll ever drive in a day except for road trips where I wouldn't take the Roadster anyway.

So battery longevity is not an issue for me.

And I always charge in Standard mode, which only charges to 90%, since I never need the full capacity. And I've never even gotten down to 50%. The huge size of the pack means I'm using a small fraction of a cycle every time I charge.

Even in 14 years when my range is 150 miles, I'll still be charging in Standard mode, since 120 miles will still be more than I'll ever use in a day.

Your comments about Nissan are irrelevant to my car. But they do reflect some people's concerns. I have a friend who decided to cancel his Leaf order because of concerns over battery life. With only 100 miles range, or 85 real-life highway miles, I'd probably judge the range to be unsatisfactory in 6 or 8 years.

The huge battery was one of the reasons I decided to go ahead and buy the Tesla. A big battery means using a smaller portion of its range each day, which extends battery life, and means less stress on the pack when delivering max power, which also extends its life. And active thermal management also extends its life. Driving the small number of miles I do, that 7-year time-to-80% could end up being ten years.

AFAIK, Tesla has not announced the battery warranty for the Model S. Evan will be more up-to-date on this than I am since he is a reservation-holder. My interest in the Model S is mostly academic at this time. I could trade my Roadster for a Model S when I get too old and arthritic to get in and out of the Roadster. It does take a bit of contortion. But for now, I'm not in the market for one. I think I read some speculation that there would be a warranty on battery degradation, but I think that's only speculation. The people at Tesla know that they are in a market with increasing competition, and while Roadster buyers may be risk takers, Model S buyers are less likely to be.

 

there has never been a single solitary word printed about any cycle rating of the Leaf battery pack.

there have been some reports by Nissan test labs stating "viable battery capacity after 3000+ cycles"

viability in EVs is considered to be 80%+ the original capacity.

other than that; there are no capacity warranties on batteries...any kind of batteries. only warranties on defects.

that is a big reason why Nissan has not stated we should have X capacity after Y years. they will replace cells that die prematurely during the warranty period and the fact that individual cells can be changed is a "no-brainer" in controlling the possible warranty costs.

 

Yes.

 

I'll agreed with this. The hybrid warranty is really just the emission control system warranty that all cars are required to have. It'll be bad PR, but as long as there is no defects and it passes emissions, a manufacturer can likely weasel out of replacing a pack with reduced capacity.

 

Let me give you an example. In most models of fuel injected American cars (not singling out GM here!), running the gas tank at or near empty repeatedly will burn up the fuel pump. Cars should be designed such that running low on gas means that all you need is to add more, yet it can trigger a $750 repair bill. So, running your Volt down to 20% SoC every trip, just because you can do it, doesn't mean you should do it? Isn't the extra $0.25 or $0.50 of gas to reduce the wear and tear good insurance over the long term? Wouldn't $500 of battery pack insurance covering 1000 trips be something that many Volt owners would pay for?

Also, is Mountain Mode something that can be engaged on the fly?

EDIT: I think, in the absence of battery pack replacement, buying a lease return Volt will be a risky proposition, as a lease holder will not be inclined to think about pack health for the long term.

 

They "think" it will be at 80%? Awesome. And yet they won't guarantee it, will they? 80% capacity isn't your issue anyway. After 3 years, you're on your own.

I deleted lots of text rationalizing how you'll be A-OK regardless. Meanwhile, GM commits to a 30% capacity loss limit in their warranty and you still bash them over unconfirmed reports (from a 3rd party blog fer crissakes) about how they manage their battery.