[silentsilverado]

Hey y'all,
I'm not a very technical person and don't have much experience with an EV aside from a family member with a 1st gen Volt. This Volt is 10 years old now and has reached the end of it's battery life and is essentially a gas powered car. Without getting into a big discussion about the Volt, this family member was told initially that the battery replacement cost would be reasonable by the time the battery needed replacement (told by an engineer who worked for GM as my family member works for GM and was around when they were showing the Volt off to the employees). Now, after 10 very happy years with the Volt the battery replacement cost is an estimated 10k. I'm aware enough about the EV tech to know that things have improved significantly since the Volt was first introduced but I would be lying if I said that I wasn't nervous about how the Silverado EV would hold up a decade down the road. Any thoughts about degradation on the Ultium platform or does anyone have any reason to be nervous about it?

 

[fhteagle]

10.5 year Volt owner here.

Volt has LiMnO2 chemistry, optimized for low temp performance and relatively high sustained C rates but not necessarily cycle longevity.

Ultium, IIRC, is NMCA chemistry, also fairly decent in the cold, doesn't need as high of C rate tolerance, should be somewhere around 2-3x the cycle life (and won't be cycled nearly as fully as the Volt in daily operation).

That being said, the high cost of Volt used/refurb packs and modules is mostly due to:

• small number of total sales of Volt, Ampera, ELR ( ~200000 ish units across 8 years of production, Ultium will probably be that many in a single year soon, and a single month within 5 years or so)
• semi-monolithic construction, such that replacing a module constitutes a destruct/reconstruct event
• very high diversion of the packs into stationary and DIY solar storage applications
• no third party retrofit option with newer / better cells, only testing and combining used cells, which Volt owners are not choosing to do in any kind of great numbers

Ultium should answer at least 3 of the 4 problems above. Not a guarantee that refurb or new Ultimum modules will be available cheaply of course, but the architecture enables module replacement far better than the Volt did.

 

[silentsilverado]

Hey, thanks for taking the time to answer! That all makes a lot of sense. It's a shame that the Volt didn't sell better, seemed to be a pretty good car. I'm definitely feeling better about the potential longevity of this truck now. I think that I keep trying to find the catch because this thing seems to pretty great on paper and I feel like I have to be missing something. I'm glad that they are taking their time and hopefully making this thing by bulletproof but I'm ready to see them start shipping them out. Thanks again!

 

[fhteagle]

I could have summarized my above post as: GM failed to capitalize on the Voltec platform for 100 different reasons, the Voltec platform absolutely did not fail GM.

Hopefully GM can be smarter with Ultium. They've literally bet the company on it.

 

[mightybobo]

Funny, I just picked up a 2014 Volt to hold me over until my truck is ready for purchase. It's at 102k miles and I'd say the battery is at about 85-90% efficiency still.

 

[HawaiiEV]

That’s not how battery failures work…

 

[fhteagle]

@mightybobo , I suggest you also sign up for the forums at GM Volt Forum . There are a lot of long time owners and great information there as well.

Not sure what you meant about 85-90% efficiency, nor how you are measuring that. As HawaiiEV said, charge efficiency is really not correlated to battery longevity in any meaningful way.

Cell balance at top and bottom of range, and total kWh delivered are your only real indications of state of health of a Gen 1 Volt traction battery.

In my case, at 10.5 years and 98k miles, my pack comes in at about 12mV imbalance top, 19mV at switchover to charge sustaining (engine on). I get about ~9kWh delivered vs the original 10.5 before the engine comes on by itself. The kWh delivered figure will vary somewhat by battery pack temperature and recall status of the vehicle (one of them bumped up the bottom buffer a bit).

 

[mightybobo]

@mightybobo , I suggest you also sign up for the forums at GM Volt Forum . There are a lot of long time owners and great information there as well.

Not sure what you meant about 85-90% efficiency, nor how you are measuring that. As HawaiiEV said, charge efficiency is really not correlated to battery longevity in any meaningful way.

Cell balance at top and bottom of range, and total kWh delivered are your only real indications of state of health of a Gen 1 Volt traction battery.

In my case, at 10.5 years and 98k miles, my pack comes in at about 12mV imbalance top, 19mV at switchover to charge sustaining (engine on). I get about ~9kWh delivered vs the original 10.5 before the engine comes on by itself. The kWh delivered figure will vary somewhat by battery pack temperature and recall status of the vehicle (one of them bumped up the bottom buffer a bit).

Lol, sorry gents, I'm still new to this junk. I just know I get closer to just over 30 miles of normal driving before the engine kicks in. Did some quick math compared to advertised mileage for original.

Sorry if I offended the electricians

 

[EV_Steve]

I have leased/owned two Volts over the course of 11 years. My current Volt is a '15 that I purchased new after leasing a '12. In the winter, the guess-o-meter indicates that I have about 30 miles of usable battery capacity, and mid-40s during the summer months. The best actual range that I ever obtained was 55 miles. (The car is still "a baby" with only 60,000 miles on the clock.)

I recall that an owner with an early Volt sold his car after accumulating around 480,000 miles and according to an inspection that was completed but the subsequent owner, the battery was still performing at 80% capacity. Now my guess is that in this case, most of the mileage was accumulated under ICE power as the original owner had a lengthy commute.

Voltec was an outstanding powertrain architecture that many had hoped would be integrated into additional vehicle architectures such as an SUV. GM was likely selling each unit at a loss and reallocated resources into EV development and the proliferation of high profit ICE trucks. In the end, it's all about Shareholder Enthusiasm. Consistently selling a vehicle at a loss or a wash does not make happy shareholders. Meanwhile, plug-in hybrid technology has found its way to nearly every other global auto manufacturer with varying degrees of success.

My '15 Volt is absolutely the best GM vehicle that I have every owned over 43 years. A perfect fit for my local driving patterns. I'd like to say the same regarding our first generation Bolt EV, but we are still waiting on that battery module replacement from GM/Lucky Goldstar and thus, are limited to 80% of designed usable capacity.

 

[Holeydonut]

Lol, sorry gents, I'm still new to this junk. I just know I get closer to just over 30 miles of normal driving before the engine kicks in. Did some quick math compared to advertised mileage for original.

Sorry if I offended the electricians

No you're right... there are many forms of battery failure. While catastrophic thermal events are most newsworthy, the vast majority of warranty replacements are due to the "state of health" (SOH) degrading over time.

California's rules require certain vehicles with battery/electric drive systems to have 10 years or 150,000 miles; and the SOH has to be above 80% as well. Furthermore, the SOH must be measurable without tools to the extent the owner would be made aware of this degradation without needing some advanced/external diagnostics to identify an issue. The observed reduction in battery-operated range is a strong indicator, but there should also some alert the vehicle gives the driver if its on on-board diagnostics believe the battery has fallen below 80% SOH. I don't know which state you're in, but it's worth reading up on it.

The other SNAFU is usually that the vehicle has to remain registered in that single state for the duration of the extended battery warranty. So a common tactic is to just re-sell them in other states... which lets the automaker drop the expensive individual-state-mandated warranty liability on that stock.

There's also a "Myvoltcapacity" app that can tell you what the vehicle is recording as its SOH.

 

[fhteagle]

I haven't found MyVoltCapacity app to be very useful. The cycle count got reset at a recall flash / reprogram event, so that's useless. The gross kWh rating that mine reports is also somewhat suspect.

 

[Holeydonut]

I haven't found MyVoltCapacity app to be very useful. The cycle count got reset at a recall flash / reprogram event, so that's useless. The gross kWh rating that mine reports is also somewhat suspect.

Looks like @mightybobo 's method of calculating SOH based on observed electric driving range is the best approach then

 

[HawaiiEV]

I would say if you have a late model hybrid or EV of some variety 10 years old and 100k miles, battery failure is very much a possibility. It only takes one weak cell to start messing up the whole pack. I went through it with a Camry Hybrid and my brothers ford focus electric was a total loss. Of course we both signed up for more, myself with the prime/Y and my brother with MME. Here’s hoping things have improved, I see modern solar batteries fail for all sorts of random reasons well before the end of the warranty. The idea that EVs are somehow maintenance free is a dangerous one, no doubt they are improving and so will third party support, but failure can be catastrophic and total the car in a way an engine or transmission wouldn’t for a typical ICE.

 

[Holeydonut]

I would say if you have a late model hybrid or EV of some variety 10 years old and 100k miles, battery failure is very much a possibility. It only takes one weak cell to start messing up the whole pack. I went through it with a Camry Hybrid and my brothers ford focus electric was a total loss. Of course we both signed up for more, myself with the prime/Y and my brother with MME. Here’s hoping things have improved, I see modern solar batteries fail for all sorts of random reasons well before the end of the warranty. The idea that EVs are somehow maintenance free is a dangerous one, no doubt they are improving and so will third party support, but failure can be catastrophic and total the car in a way an engine or transmission wouldn’t for a typical ICE.

The State of California agrees with you, that's why they made the extended warranty requirement on vehicle batteries cover 10 years / 150,000 miles. To California policymakers, this is a reasonable full lifecycle of a vehicle. Sure, some people have a car that could last 20 years, but for the sake of policy, they arrived at 10 years. The IRS treats light-duty vehicles as a 5 year operable asset for depreciation purposes, so 10 years errs on a longer asset life.

But based on your comments, this could still be "dangerous." So what steps do you recommend for BEV and PHEV and Hybrid owners take to perform maintenance on their vehicle batteries and "drivetrain" to make things safer? The manufacturers don't really recommend much beyond replacing wear parts and sometimes tell owners avoid charging and maintaining charge at 100%.

Tesla Powerwalls have a lifecycle SOH threshold of 70% before it triggers a warranty issue. But again, there is nothing that a homeowner is supposed to do for maintenance.

So if this lack of attention is "dangerous" - it's not clear to me what someone can do to address the danger (besides just not owning the product).

 

[HawaiiEV]

There’s nothing you can do besides save money for a rainy day. The danger is when someone buys a used EV or hybrid at 10 years and assumes it’s like buying an ICE Camry with 150k miles on it. It’s not. I can appreciate the law makers arrived at 10 years, that’s a decent compromise and probably realistic for middle class car buyers in California buying EVs. Again I worry for people who buy used vehicles out of warranty thinking they are comparable to used ICE of similar vintage. Every vehicle I’ve ever owned, which as been many, has made at least 20 years without a major failure, except for the Camry hybrid. Just because your powerwall has a warranty doesn’t mean it can’t fail, and if it fails on the big island of Hawaii it can take months to get service and a replacement. The same will be true for EV pack failures in warranty.


The battery pack is more then half the cars value, there’s a reason the manufacturers drag their feet on replacement. The resources to make the packs are in short supply, they make their money selling a whole car.

 

[Holeydonut]

There’s nothing you can do besides save money for a rainy day. The danger is when someone buys a used EV or hybrid at 10 years and assumes it’s like buying an ICE Camry with 150k miles on it. It’s not. I can appreciate the law makers arrived at 10 years, that’s a decent compromise and probably realistic for middle class car buyers in California buying EVs. Again I worry for people who buy used vehicles out of warranty thinking they are comparable to used ICE of similar vintage. Every vehicle I’ve ever owned, which as been many, has made at least 20 years without a major failure, except for the Camry hybrid. Just because your powerwall has a warranty doesn’t mean it can’t fail, and if it fails on the big island of Hawaii it can take months to get service and a replacement. The same will be true for EV pack failures in warranty.


The battery pack is more then half the cars value, there’s a reason the manufacturers drag their feet on replacement. The resources to make the packs are in short supply, they make their money selling a whole car.

Lol ok, when I see "dangerous" I'm thinking the Darkwing Duck definition where someone's about to have a bad time and get hurt. You're just talking about potential financial harm.

I agree ... these early-adoption BEV and PHEV vehicles will be much harder to keep on the road than a Ford Econoline or F150. So, people buying these aged electric vehicles will benefit from having access to facilities / resources to repair a battery pack. Or, these owners should be ready to eat a big surprise cost that effectively wipes the car out if the battery warranty is exhausted.

About the Powerwalls... it's not just a Hawaii supply chain thing. Nobody gets service from Tesla on their Powerwalls because to your point Tesla would rather sell to new customers rather than honor warranty commitments. Edit (I won't crosspost other forums), one customer cited 7 months to get a replacement Powerwall in Southern California.

But on the plus side, there aren't that many instances of the Tesla Powerwall physically failing (although the units are mostly in their infancy). Issues are usually due to the solar-inverter failing or something buggy with Tesla's software update.

These things are only expected to have a 10 year life anyway... and there's no real way to get them used. Time to start saving for that rainy day lol.

 

[HawaiiEV]

We have drastically different levels of empathy and I imagine experience with the general public when it comes to understanding these concepts.

 

[Holeydonut]

We have drastically different levels of empathy and I imagine experience with the general public when it comes to understanding these concepts.

Considering I said I agree with you - I can't tell what you're trying to say.

 

[HawaiiEV]

Yes and going into a recession when someone finds out a battery replacement costs more then they paid for the vehicle people will “have a bad time and get hurt”

 

[Holeydonut]

Yes and going into a recession when someone finds out a battery replacement costs more then they paid for the vehicle people will “have a bad time and get hurt”

So you're saying @fhteagle, @mightybobo, and @EV_Steve don't know what they signed up for? They talk about enjoying their high mileage vehicles and you're here explaining how "dangerous" the mindset is.

Anyway, the only thing I see on this forum that is "dangerous" is that dude doxxing his wife's name, address, and 16 digit credit card number in the GMC Sierra EV Sub-forum. And the mods there don't give enough care to delete the PDFs with the PII. There's no point in protecting people from dangers man. Just let them enjoy their high mileage Volts.