Zero Chevrolet Volt Batteries Replaced So Far Due To “General Capacity Degradation”


Chevrolet Volt

Chevrolet Volt

Gen 1 Chevy Volt Battery Pack

Gen 1 Chevy Volt Battery Pack

Recently, General Motors invited members of the press to its Brownstown Battery Assembly Plant for a tour and a sit down discussion with some execs.

As is often the case in these sorts of events with the wider press, not a whole lot was revealed that we didn’t already know, but there was a brief discussion on the first-generation Volt of interest.

According to Autoblog, the Brownstown factory is still tooled up to produce batteries for the original Volt:

“Despite the highly touted second-gen Chevy Volt going on sale last year, GM still has the capacity to build battery packs for the old, first-gen model. This is because the company is legally required to be able to provide replacement packs for warrantied vehicles (for up to 10 years)…”

That’s normal in the industry, but when asked if General Motors has replaced a gen 1 Volt battery pack, the response was surprising.

 “a grand total of zero Volt packs have been replaced because of “general capacity degradation”…”

We’ve known that the Volt pack is robust and that it has a lot of built in buffer, but never would we have imagined that not a single pack has suffered from “general capacity degradation.” And there are some seriously high-mileage Volts out there, so it seems the verdict is in…the Volt battery pack stands the test of time.

Source: AutoBlog

Categories: Chevrolet

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152 Comments on "Zero Chevrolet Volt Batteries Replaced So Far Due To “General Capacity Degradation”"

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I always thought that Pack Management System made more sense than just a Thermal Management System, but the acronym doesn’t work quite as well.

Perhaps the bigger picture is:


(hope that didn’t sound too moody)

I am not completely sure I really want to know, but what is LGC? 😉

LG Chem

… See? Your acronymaphobia was unwarranted.

Small correction it’s LGCMI

Technically LG cpi did the original volt design before Gm brought it in house and now LG cmi makes the cells only for the volt pack.

I can work with that acronym!

After 5 years in my Gen 1, 60k EV miles, still haven’t noticed a drop in range. I’m not measuring it with a device though….

My experience exactly, 5 years and 90,000 kms.
Somedays I wish they would expand the usable capacity a bit beyond the current 65%. Maybe they were a bit too conservative??

It would be cool if we can open it up to 90% after the warranty runs at 8 years. Heck, I would be willing to give up my warranty if I could hack the pack and get it to open up to 90%.
I would only use the extra miles one or two days a month at most so it wouldn’t change my gas usage much but it would be cool to stay gas free even more frequently.

Almost 4 years and 64,000 KMs and no difference. I use mainly battery, my lifetime is 0.76 L/100KMs.

Right, maybe after 10 years, they could give you and additional 10%.

when you open it up, you will realize that it actually degraded. you didn’t notice it because it didn’t go below 65.

At a starting usable value of 65% pack usability, it would be easy for the Volt’s computer to automatically raise the usable percentage of the battery pack as the battery capacity degrades. In this way, it would appear that GM batteries have amazing longevity.
Not to say this is bad. Exceeding customers expectations is always a good thing.

There has been a lot of discussion of whether this is in fact happening at GM Volt dot com over the years. It may be happening but I don’t think so. Weber made comments about when the AER starts to drop that made it sound like the Chevy mechanics would be able to program the Volt to dip deeper into the pack later in the Volts life, but that was years ago and I don’t remember exactly what he said.
One way or the other though, whether it is already happening or not, we will end up using more than 65% of the Gen I’s pack capacity before the Volts get recycled.
I think that the robust pack management system the Volt has means that the Volt pack will be aging out due to calendar life rather than miles, and that the people in Arizona will be the ones to see battery degradation first, just like the Leaf albeit a lot later.

According to my memory that’s exactly what it does. I seem to remember a GM spokesperson confirming that the software maintains range while the battery degrades

Same. On warmer days I’m actually ABOVE the range I had when I first got mine in 2012.

Limited charge window. 65% DOD, or using only ~10.5 kwh of a 16.5+kwh battery extends cycle life. That, and rumor has always been that Volt is programmed to consume more of its buffer in order to keep allowing the ~10.5 kwh draw.

My opinion of the quality of engineering of the Volt continues to rise over time. Zero battery packs experiencing premature aging isn’t merely an impressive engineering achievement; it’s awesome!

Too bad GM sat on the tech for so many years, making no substantial improvements for five years after first producing the Volt 1.0, and not putting Voltec into any other car except the Cadillac ELR. The ELR, as a commercial product, managed to snatch defeat from the jaws of victory, sabotaged by such things as an absurdly cramped back seat and absurdly high pricing.

GM made battery chemistry improvements throughout the life of Gen1. They were also developing Gen2 during that time, so I don’t think they just “sat” idle.

Correct. If anyone is to be accused of sitting idle it is Nissan who were slow to respond to their battery durability issues.

5 years down the road we now know GM EV engineering is ready for primetime, it has stood the test if time. They should have a hit with the Bolt.

Kdawg said:

“GM made battery chemistry improvements throughout the life of Gen1.”

Hmmm, well the battery maker made improvements in the chemistry. Not sure GM deserves and credit for that.

“They were also developing Gen2 during that time, so I don’t think they just ‘sat’ idle.”

Okay, perhaps I overstated the case. But altho they may have been working on Voltec 2.0, I don’t think it’s any coincidence that they delayed actually putting it into production until other auto makers got close to marketing next-generation PEVs.

Can you imagine Tesla sitting on improved tech for years and years? I, for one, cannot!




Of course GM is in the compliance business. They would sell 10 times the Voltif not, there would be an all electric Volt, many adaptations of the Voltec to other vehicles, etc.
Like all other ICE car makers, they wish the electric revolution will never bloom.

The they may change their mind pretty soon because of the autonomous car that REQUIRES an all-electric drive to be competitive.

Rex, there just aren’t that many people that want a GM electric car. If Tesla could build a car that is exactly the same as the Bolt, they could sell 100,000+ a year. With the Chevy bowtie on it, Chevy will be lucky to sell 35,000 the first year and 50,000 the year after.
Teslas cachet is unusual, that cachet does not extend to other electric cars. Or at least it won’t until gas prices get back up above $3 a gallon again.
Greens talk a good game but they aren’t willing to put their money where their mouth is.

A 40kwh (real world 150 mi) Chevy Spark should cost in the low $20k’s (no tax credit) and GM would still make their regular profit margin on the sale.

You’d see all the “greens” and frugals come out of the wood work with cash in hand to buy that car.

A Spark LS MSRP is $13,875, 40 kwh from LG Chem is $5,800 ($145 x 40 = $5,800) ….. tell me I’m wrong.

You’re not.

Engineering and development is expensive. You cannot just drop a bunch of cells in the back seat and call it done.

No. You drop a bunch of cells UNDER the back seat … and call it done.

The Spark EV has perfect 50/50 weight distribution, with little impact on passenger or cargo space. The pack is exactly where it should be.

Spoken like a true non-engineer.
An engineer

I think Ned is right, it isn’t that simple.
A pack costs a lot more than the cells alone. If you were able to add 21 kWh to the Spark EV it would have an MSRP of $28k, at least, if GM wanted to make even a 10% profit on it. And GM is not going to give the Spark EV away at cost.
The electric car market is limited by a lack of really good choices and the current expense of building a quality pack like Tesla and GM are building.
Tesla is getting the price down faster than GM but they aren’t that far apart now. Maybe the Bolt will be breakout electric car for the masses here in the States, but I am not holding my breath. GM has built crappy small cars for too long for them to sell a small car at a premium, electric drive or not.

Of course that $145 number is for the cell cost only. But even at $200 at the pack level per kWh it would still come in around $22,000 which is in affordable car range even without the tax incentives.

You aren’t wrong, but you aren’t using an accurate comparison or considering all costs either. The Spark EV is based on the fully loaded $15,440+ 2LT model, bringing the post-incentive price quite close. And the EV is more than just the standard ICE plus battery. The suspension, steering, traction control, (and so much more) required at least retuning, and quite often unique, upgraded components to compensate for the much greater power, torque and weight. None of this is free, nor is the engineering and testing hours required to so effectively integrate it all. I appreciate the point you are attempting to make, but you haven’t factually done so.

carcus said:

“A Spark LS MSRP is $13,875, 40 kwh from LG Chem is $5,800 ($145 x 40 = $5,800) ….. tell me I’m wrong.”

GM’s price for the Spark EV is irrelevant. It’s a compliance car, and thus sold with a price below cost. The price doesn’t reflect the cost of making a car and selling it at a profit.

You can’t just take that number and project it out. The cost of making a car is greatly dependent on the volume of production. Higher volumes means lower unit prices, so cars made in larger number cost the manufacturer less per unit.

There’s a Catch-22 for PEV manufacturers: They can’t sell PEVs at a low enough price to compete with comparable gasmobiles, partly because the unit price on PEVs is higher than on gasmobiles, because most PEVs are made in relatively small numbers. And the market for PEVs will remain small until they are priced to match comparable gasmobiles.

Of course, that’s typical of a new product during a disruptive tech revolution. And it’s a large part of why there is an “S-curve” of adoption during such revolutions, with accelerating growth of sales when prices for the new tech come down.

Zivvermann Good electrics would be sold in large numbers, whatever the brand name. The demand is potentially huge once people get to know all the advantages.

See here how they do to NOT sell good EVs.

Gross oversimplification at it’s best.

I look at the forest… 🙂

RexxSee said:

“See here how they do to NOT sell good EVs.

It’s no surprise that a die-hard conspiracy theorist like you, RexxSee, sees economic realities like those on that list as indications of a vast conspiracy to suppress compelling EVs, rather than a result of market forces motivating legacy auto makers to direct their efforts toward preserving their market share.

It’s not that the executives running legacy auto manufacturers are prejudiced against EVs, and want to suppress them… contrary to what the propaganda film “Who Killed the Electric Car?” repeatedly claimed or at least implied. It’s that legacy auto makers can and do make more money selling gasmobiles than they can and do selling plug-in EVs.

Not a conspiracy. Just basic economics.

Same result. No need to insult me. Same dangerous irresponsible poisoning of the global climate balance..

Still, the very definition of capitalism and competitive advantages imply routine every day conspiracies, exactly the same found in team sports, hunting all across the nature. Conspiracies, plots and schemes to win a war or a contract are the same present in our genes for millions of years. Negating that conspiracies exist is playing outrigger, and believing the Kool aid of the global corporate P.R. in action for governments and companies through the Media every day since over 80 years. Smooth pervasive propaganda.

Not outrigger, ostridge.
I will add that the very expression “conspiracy theory was put in place as a camouflage by the same corporate forces who make the most of conspiracies.
You should read a little more Chomsky and BERNAYS, and watch a little less TV.

If you look closely, you will find that the blue writings will highlight and underline itself if you hover your mouse over it(Press F1 to know how to hover)… and it will lead you to another web page if you click on it!
Like magic!
/Sarcasm off

Now notice that the 50 ways to delay the EV Revolution are not my delirium paranoid inventions. They are a compilation by the main editor of a well known Green Car web site, with inputs by various commentators.
So your personal attack about conspiracy is just that : a personal attack.

I’m sorry for you if you think necessary to rely on such low tactics to prove your point, because you are at times very articulate in your comments.

Rex, I agree that demand could rise once more people realize the luxury feel of electric cars, but I don’t think that there are that many people who will forget about Chevy’s dismal history of building ratty small cars.
I think part of the reason Tesla is doing so well in the luxury market is simply that they are new and cool and the Spacex cool is rubbing off on Tesla.
But it still costs a lot of money to build a 200+ mile battery pack and the electric intent parts that a BEV requires. That fact is going to be the tall pole in the tent for a few more years.

RexxSee said:

“Of course GM is in the compliance business. They would sell 10 times the Volt…”

This isn’t merely factually incorrect; this appears to be what passes for “thinking” in the mind of a dedicated conspiracy theorist.

You have to ignore reality pretty firmly to call the Volt a “compliance car”. It’s one of the three top-selling PEVs in North America. Furthermore, GM advertised it heavily when it was new, and in the first 2-3 years, produced it in higher volumes than they could sell.

Now, I agree that GM should be castigated for not putting Voltec into different vehicles, or in fact into any other car except the Cadillac ELR, which indeed appeared to be designed to be a compliance car, made in small numbers and vastly overpriced.

But that doesn’t justify calling the Volt a “compliance car”.

Says the fanboi.

Nothing about the Volt is compliance.

1) It has an engine, thereby getting less credits. They also did not sacrifice performance or utility for more credits (like the i3 Rex)

2) It has a large battery buffer and TMS to prevent degradation. In other words, it was engineered for all climates and for the long haul.

3) It is sold nationwide.

4) Troll.

Wrong, and irrelevant to the quality and longevity of GM’s batteries and TMS. You could really benefit from toning down your hyperbole.

They could increase sales, if they put a wagon version out, for rear seat headroom.

And, apparently teach the dealers to deduct Federal and State Tax Credits for Lease buyers. BMW and Nissan do.

No wonder they’re only selling 2000 a month.

Absolutely false. GM substantially upgraded the battery pack twice during the production of Gen 1 Volt, along with many other tweaks and cosmetic changes.

“Absurdly high pricing”. You keep being corrected on this point, yet you still make it – that’s mental masturbation. I paid just $4000 more for my ELR than I did for my VOLT, and got more car, and more AER range. As far as available space, Sport Coupes always have had less than Ideal rear seats. In this car’s defence the 2 seats can be used in a pinch without greatly compromised head room, and they are the same high quality as the front seats. But the tallest people should sit up front. The thing that really killed the ELR was Cadillac’s soft-sell advertising, which in general I’ve never liked. But what do you expect with that idiot DeNyschen in charge, an EV-Hater from years back. There is absolutely no good reason to have discontinued the 2016 ELR from production after 4 months, since all parts have to remain in production for the very long warranties of the GEN 1 volt. I’m not exactly wishing for astronomical gas prices, but the USA’s extremely low-cost gasoline has greatly dampened interest in this car. Cadillac also should have ‘hard-sold’ it qualtity features, as well as its sophisticated suspension, which, even though I… Read more »

The right wing media, the paid Exxon Trolls killed it. They’ve been pumping out anti-green propaganda for DECADES.

Bill Howland said:

“[quote]Absurdly high pricing[unquote].

“You keep being corrected on this point, yet you still make it – that’s mental masturbation.”

You disagreeing isn’t at all the same as you actually correcting me, Bill. As for the second part of your unprovoked personal attack: Try looking in a mirror, dude. Many of your comments show a noticeable departure from reality, and this is certainly one of them.

“I paid just $4000 more for my ELR than I did for my VOLT, and got more car, and more AER range.”

And you certainly didn’t pay the ridiculously high price at which the ELR was initially offered, now did you? You bought it only after Cadillac dropped the price substantially. And if you paid the low, low price you claim, then I would guess you got a remaindered car during a year-end sale; one that the dealer would have had to re-sell back to Cadillac at a loss if they couldn’t have sold it to you or someone like you.

Am I wrong?

I’m going back to the one-sentence responses, unless there’s some intelligence in the thought, since you can’t come up with one instance where I’ve “departed from reality”.

Price was more harmful the design was nice.

My ELR doesn’t have a cramped back seat or an absurdly high price.

The back seat is similar to any other 2+2 layout. Which is what I wanted.

The price was $30k off MSRP which is also what I wanted.

Yeah Loboc, its a nice car, and its apparent all the clowns have thick heads because one never can get the point through to them.

As far as the ‘absurd pricing’ goes, I could buy 3 ELRS for the price of 1 X, have much less trouble, and have change left over.

So all comments being made by the clowns are truly devoid of reality.

I think Volt is one of the best engineered car ever, now with 5th seat in new Volt and improved range is the best combination possible. Unfortunately message to public has not been delivered.

It’s a compact car, there is no real “5th seat”. I’d rather be stuffed in the trunk.

Fine, you sit in it! :p

If only GM would let gen 1 owners, when fheir battery came to the end of its useful life, could put a gen 2 battery in the car for longer range (45-50 miles instead of my paltry 35).

I’ve been getting 65-70 mile range everyday in warm weather in my Gen 2…for months.

I also wonder if they would open up the usable capacity after its off warranty – say from 65% to 90%….

Well, it is 18.4kwh. BMW’s i3 is, what, 22kwh right? This is conservative, bow tie GM not fluffing their numbers.

They deserve tremendous credit, fan boy or not.

I figure more energy, thoight, and testing wemt into the Voltec Drive Train, than the Volt Car itself!

At 6’3″, the back seats of the Volt AND the ELR, are like Torture Chambers!

I have not checked out the new Malibu Hybrid for fit, but I think it could be much better fit! Now, if they could take just 50% of the 60 kWh of the Bolt EV Battery, for a 30 kWh pack, and fit that, along with 100 kW DC CCS Charging, and 9.6-10.0 kW AC Charging into the Malibu, I would think the resulting ~75-85 Mile AER EREV could really elevate the evidence they are realy in the game!

PHEV’s/EREV’s and BEV’s need to be found in every vehicle size and segment by 2025, and all BEV’s, except for the few extreme cases where high range PHEV’s still make sense, by 2035!

A 6’3″ person sitting behind a driver who is at least 6′ is probably a torture chamber for anyone sitting in ANY compact car…or even mid sized car.

Well, believe it or not, the 1991 Four Door Chevy Sprint (GEO Metro) that I bought new, was More Head and Leg Room capable, than the Volt! And, I set the Front Seat for myself; for pedals, steerimg, and mirror comfort, and the climbed into the back seat to check it! While it was snug, it was not rediculous in Head, Leg, or Knee Room!

I check ALL 4-Door cars the same way! I used to travel to Tall Club International Events, where I was usually the shortest guy, since minimum height for men was 6’2″, and for women was 5’10”! I still know tall friends and neighbors, so should the need arrise that 4 of us are in my car, I don’t want to cripple anyone!

I suggest a Bolt EV for your height.

Or a Fusion Energi

Maybe! Except that I already put my $1,000 down on the Model 3! Even then, I might need to head to California and do a physical fit/sit test next spring when the Beta Test cars are running, to verify the actual fit results!

If Tesla stays true to form, they will have production-intent models touring the US for test drives only for reservation holders. You’ll be able to check out the 3 without a trip to Cali, unless you really want to.

I put a deposit on a Model 3, day one as well. But I’m still on the fence between a Bolt EV and a M3. Luckily I should be able to keep driving my Volt until I can actually order an M3. Who knows how long that will be, but if it’s 2019, I probably won’t wait any longer. Or if I hear a bunch of horror stories from the first buyers, I’ll prob. get my $1000 back.

I wonder what Sumo Club International is going to require for GM cars. 🙂

I hear they are partnering with ‘Short Man Browns’ clothing store for travelling buddies!

Or maybe get a Buick LaCrosse

“According to statistics from the Centers for Disease Control (CDC), only 5 percent of  American adult men are taller than six feet two. Shaquille O’Neal towers seven feet one inch, wears size-23 shoes, and had listed his weight at 325 pounds during his playing days. That’s a lot of retired NBA center to shove behind the wheel of a Buick LaCrosse for a pair (one is shown below) of commercials.”

Robert, Robert, Robert, knock it off with the seating arrangement in the Chevy Volt Extended Range Electric Vehicle.

US News and World Reports gives the MY 2011 Chevy Volt the honor of being the number one Used Upscale Midsized car out of 62 competitors!

(Note- Argue if you want US News designation of Upscale Midsized Car. If you hold fast that Volt is a compact it still knocks the socks out of 62 other ‘Upscale Midsized’ competitors!)

Take a second and be awed as to this accomplishment!

Link Goes To Us News-

Again Robert, your snide remarks about the Chevy Volt’s back seat really fall on deaf ears!

Here is my associate at 6 feet, ten inches tall and 346 pounds sitting in the back seat, door closed, me driving!

Link Goes To Twitter-Photos / Nuff Said-


Thomas J. Thias



Forget replacement packs, there are still no confirmed cases of any kind of significant battery degradation in any of the Gen 1 Volts. Erick Belmer’s sparkie is still going strong with over 100k EV miles/300k overall miles with no hint of degradation. Compare that to a Leaf. 😉

Amazing to think GM initially projected that ALL Volts would need their HV batteries replaced during the warranty period. Turns out none of them have been replaced due to degradation so far.

“GM is expecting each and every Volt will need a new battery pack while it is under warranty”

I wonder if that was part of the cost equation for the original Volt? I also wonder if that was one reason GM has been hesitant to push the technology until they have seen proof that it is reliable. I know they’ve had all sorts of problems with their mild-hybrid systems.

The $5k haircut the ’14’s got….that didn’t come out of thin air. GM probably realized that their initial warranty claim costs for the Volt were waaaaaaaaaay overstated, which probably let the bean counters approve the price chop.

I’ve seen a couple posts reference “X” number of EV miles vs total miles. In the Volt, they’re all EV mules whether the ICE is running or not. The engine is nothing more than a generator in the Volt, and never drives the wheels. All miles are derived from the battery packs and electric motors.

Good point.

That is not the case at hichway speeds when the battery is depleted.

What is meant by the term is that the motive power has come from the wall socket, not a gasoline pump – exactly the same as a pure BEV.

As for the engine being just a GENSET as it exactly is in the I3 REX, there are 2 big economies not found in that vehicle:

1). During steady-state highway driving, the mechanical output of the engine is substantially directly used – avoiding the “Generation- rectification – inversion- and motoring’ losses.

2). During the winter time the engine cycles – usually just enough so that a significant portion of the otherwise totally wasted heat generation is utilized in the cabin, saving valuable electricity.

This applies for both the Volt and ELR.

Garth said: “I’ve seen a couple posts reference ‘X’ number of EV miles vs total miles. In the Volt, they’re all EV mules whether the ICE is running or not.” The term “EV miles”, when talking about a PHEV like the Volt, is a term of convenience. It means miles powered by stored electricity from the battery pack, as opposed to miles powered by gasoline. It is entirely proper to account for “EV miles” and “gas-powered” miles separately in a PHEV. In fact, that’s the only way to do so which makes sense. Unfortunately, far too often the two are lumped together, and so Volt drivers often claim a “MPG rating” much higher than anything reflecting reality. Some of us call this “fake MPG” as opposed to “real MPG”. Garth continued: “The engine is nothing more than a generator in the Volt, and never drives the wheels. All miles are derived from the battery packs and electric motors.” That’s not strictly true. The gas motor is mechanically connected to the car’s generator, and there is clutch between the generator and the drivetrain. Sometimes, when the battery pack is low and the car is called upon to deliver strong acceleration, that… Read more »

You leave a large buffer on each end and don’t let them get hot…. they”ll last forever.

Is this the moral of the story here?

Ask Nissan. 😉

+117,000 (cumulative Volt/Ampera sales)

Yes, good engineering, wins again.

That’s not the same as saying that no battery pack capacity degradation has occurred. The Volt’s battery pack manager is likely reducing the buffer size rather than the useable capacity as the inevitable degradation occurs. The electrochemical reactions that occur at each battery cell’s electrodes can’t be 100% reversible because there are always destructive side reactions that occur resulting in degradation. Of course, buffer reduction can’t go on forever as degradation increases, but apparently the buffer size is large enough and the degradation minor enough that a Volt’s battery pack has a good chance of outlasting the car.

If it outlasts the cars by a lot, perhaps we will start to see GM home solar batteries based on old Voltec packs like Nissan and BMW are doing with their respective old car packs.

Art, I think it may be several years before we know how long the Volt packs are going to last. And that is a good thing. I haven’t had my Volt that long, just 38 months, but I am right at my usual 44 miles on the guessometer this morning, same as I had in month 1.
I leased my Volt because I wasn’t confident that the pack would last and I wasn’t sure what the true pack replacement price was going to be. Looking back, that was kind of shortsighted.
Interesting thing is that even though my residual value on the lease was $25,400, US Bank just sold me my leased Volt for $14,500. Since I know the Volt it is worth it to me. I am pretty happy with the deal, I will probably not sell this car for years and I strongly doubt that I will need to replace the pack.
The one question left is, could the Volts battery be calendar limited rather than mileage limited.

In view of the fantastic warranty the cars have, Bob Lutz had the design of the battery made for 10 years / 150,000 miles.

It is quite apparent to me even those huge numbers are conservative.

And a base 2011 Volt, $40,000 MSRP, is easy to find for $10,000 just 5 years later.
Amazing how great the deals are for used Volts.

i have a 2012 volt and have not noticed any degradation in battery capacity. i haven’t actually measured for such, but i have not noticed any reduction in range that would prompt me to want to investigate.

True every charge and discharge cycle causes slight battery degradation. However in an interview with with Andrew Farah years ago, he was VERY specific that the Volt does NOT adjust its operating buffer to compensate for capacity degradation. I failed to find the article but I clearly remember there was no confusion or ambiguity in what he said

I understand that the bulk of the degradation occurs at the top end and the bottom end of the charge. If only 65% of the range is use how much degradation is actually occurring?
Does anybody know whether the Volt is designed to alter the buffer over time as Art Isbell is suggesting?

“As the battery ages and energy storage capacity of the lithium-ion cells degrades, control units will widen the percent state of charge band to continue to deliver the range goal.”

Chevrolet Volt Will Utilize 10.4 KWH of Battery to Achieve EV Range

David said: “Does anybody know whether the Volt is designed to alter the buffer over time as Art Isbell is suggesting?” There may be some confusion of terms here; perhaps GM engineers are using terms differently than they’re used by us laymen. There are some things which must be correct: 1. Li-ion batteries degrade over time, as they’re cycled. Doesn’t matter what kind of li-ion batteries GM is using, that will be true. 2. Since battery packs degrade, the available charging capacity of the pack, the total kWh, will shrink. Since the Volt’s battery pack appears to not degrade over time, simple logic suggests this must be achieved by reserving a certain portion of the original capacity, so that it’s unavailable when the battery pack is new. That is, there must be a significant kWh difference between total battery capacity and usable capacity. Simple logic also suggests that this reserve, or “buffer”, must be gradually released over time to compensate for the inevitable loss. It’s unlikely that GM is able to use magic to prevent battery pack degradation. 😉 If someone in a position to know says otherwise… well, I wouldn’t accuse anyone of lying without seeing a direct quote.… Read more »

Good Engineering? Are you sure. Look carefully…”a grand total of zero Volt packs have been replaced because of “general capacity degradation”.” That means there are battery replacements but tag with different reasons. Otherwise the factory won’t continue to build replacement battery packs for the first-gen model!!!

Unless you can specify the quantity & reasons for any replacements, you post is irrelevant in regards to the engineering aspect of the long life of the cells.

You’re confusing all defects to “capacity degradation”. Sure, there could be defects in manufacturing the cells and the pack and the car. Article is about capacity degradation after the car’s built according to spec and has been running for a while.

As for cell defects, there was a story that only 2 out of a million Volt cells are bad due to manufacturing defect.

2 in a million?!


You’re essentially applying the false logic you accuse the initial claim of. I had a 2012 and had the battery replaced … because the service department got coolant inside it. Nothing to do with the battery engineering.

My co-worker had his battery replaced due to wife t-boning a tree. Replacements are needed for issues unrelated to quality.

The 2017 Chevy Volt is a fun sporty car to drive and by a good margin the best bang-for-your-buck EV available today.

…But the Volt remains relatively unknown to the general public. Most GM dealerships continue to exclude the Volt from the front showroom line-up and will *reluctantly* dig one up (most often with a non-charged battery) from the back lot only after first trying to steer you into a tradional ICE model.

There are a handful of exception dealerships but not many.

Volt’s been out only 5 years, so there’s still time for warranty claims. But based on 2015 SparkEV, which is pretty much Volt cells and cooling, there won’t be much (or any) warranty claims.

I’ve used DCFC on SparkEV probably hundreds of times in 1.5 years, and it’s lost about 1kWh capacity, or 5%. SparkEV is warrantied to 8 years, so it could be 0.95 ^ 8 = 66%. It’s warrantied for 65%, so it’s not likely to degrade for warranty claim. This assumes the exponential decay will hold, but initial degradation is probably far worse, which means even less likely for warranty claim.

Volt doesn’t have DCFC, nor does it get “abused” like SparkEV, such as charging to almost 100% and discharging to almost 0; SparkEV uses almost full battery capacity, whereas Volt is “babied” to use 80% (or less). I’ll be surprised if any Volt battery warranty is claimed.

More interesting would be battery capacity degradation pattern observed by many people over years. That will tell us how long the battery could last.

You sure the warranty is only 8 years? Thought California required 10/100.

I think that applies to hybrids. All electric are not under the same emissions rules since they zero emission.

If you’re eligible then it needs to be 10 years – 150K miles. The 2011 MY weren’t and came with an 8 year 100K warranty. The VIN tells you whether the car is compliant with the higher emissions regulations.

While my dealer did a good job promoting and selling the Volt I was amused to find that they sent me out the door with a full tank of gas and a nearly empty battery. The full tank of gas was apparently a policy at that dealer. Oh well, some things take time to change. BTW, after 8 months still have most of that initial full tank.

You better use that gas before you get to the Fuel Maintenance Mode…

General capacity degradation means average capacity expressed in % of original capacity right?

Sill GM could replace single cells/parts of packs to fix smaller in scope issues.

But it validates “new” thinking that battery packs can be “maintained” and thus can last longer period of times.

People who started Tesla had hardest time convincing battery supplier that big battery packs can actually work, while not causing fires in cars during “normal” car operation.

So the progress is huge.


I think GM has replaced a small number of battery packs due to things other than degradation. Not sure but I think it just replaced the pack.

Pretty sure they replace the pack. Simpler, safer and the manufacturer will want to see the whole pack to figure out what went wrong.

Tesla lends the owner a pack, ships the old pack somewhere they can fix it, fixes it, and then swaps the battery pack out again.

Battery packs are too expensive not to fix individual cell/module failures.

przemo_li asked:

“General capacity degradation means average capacity expressed in % of original capacity right?”

Not quite.

If when you say “average capacity” you’re talking about the average of the cells in the pack… then no. Li-ion packs are limited to charging cells to the highest voltage any individual cell can tolerate, not the average. So the limit would actually be the one cell in the pack with the worst degradation, unless that cell is somehow cut out of its connection with the rest of the pack.

This is one reason why li-ion battery packs must have a BMS (Battery Management System), whereas other types of battery packs don’t. A BMS ensures balanced charging and discharging, to prevent any cell from being either overcharged or drained flat, which would cause it to lose capacity faster than other cells.

This bodes well for one day having thermally controlled 150kwhr packs that are limited to 100kwhr, with full 300+ mile recharge in 20 minutes lasting more than a million miles before getting repurposed.

And, of course, dangerous acceleration.

Yippie. I want all the dangerous acceleration they can give me ?

I bet there’s a lot of disappointed bats who were counting on battery failures since GM turned the battery cases into bat homes…#BatLivesMatter #GiveUsFastCharging

As we learned from low sales and awful Volt resale values, few care about reliable battery tech…Lease and fast charge all you want…Turn it and get latest and greatest model, maybe GM will finally add a garage door opener into the Gen2 at your lease turn in!

Honestly, I think a lot of the lower resale value right now goes into potential uncertainty in the technology.

It wouldn’t surprise me if resale values actually tick up a bit in coming years, once the technology is more accepted, durability is established, and gas prices (maybe?) increase.


Gas prices would have a direct effect however the as tech improves it lowers resale…Volt in particular has a habit of increasing range every other year and we know GM has a very long time before the MY18 will get released…Let’s say they improve the range by 5 miles, it will have a negative affect on MY16/MY17’s resale…

Yes. So long as PEV buyers expect electric range to increase substantially in the near future, the resale value of those PEVs will suffer. Not exactly the Osborne Effect, but something similar.

Tesla is smart to increase the capacity of their cars’ battery packs only incrementally, so buyers don’t see much difference in range between this year’s Model S vs. last year’s.

Thumb up for Volt engineers

Agreed, now if only the packaging engineers could put the voltec masterpiece into something compelling platform…

All great.
Still it’s much more a very defensive choice of limiting a 17 kWh battery with a 10.7 or so kWh of working energy and limiting fast charging of the pack than anything about high tech BMS and cooling BS sort of explanation.
That approach would work good on anything. Even Leaf battery would have gone a lot further with that.
But who would have like to use just 15 kWh of 24 kWh right of the boxes?
“If it’s too strong, it won’t break!”

You realize that you can generate up to 60+Kw of regen going down a steep hill right?

yep, all that regen goes back into the battery. Accounting for losses, you’re still looking at 50+kw of power.

Check this reddit post:

While I don’t agree with why Chevy left out fast charging capability, it certainly is capable of it. they left it out not because they wanted to baby the battery pack, but they did it because the car has a very capable range extender.

I do and having a good regen power available is very valuable and it’s too poor on other (Leaf).
I wish I could have more on mine.
But having 50 kw of regen power for a few second isn’t the same has having fast charging capability of 20 minutes or more.
Beside, the fact that there is much more left capacity in the Volt battery might be one factor permitting more regen power.
It easier filling an empty pool then trying to top it.

10.4kWh out of 16kWh (17kWh is only the 2015 models). So 2011/2012 only had 16kWh.

65% isn’t all that terrible. You can do the same with the LEAF and see how much better it would perform or NOT.

Regardless of how much GM babied it, unless you can show that “any other” battery can do the same with same amount of babying, you are just being a sour grapes…

Also, DCFC for 20 minutes makes no difference if cooling system can take care of it. LEAF doesn’t even have an active cooling system. That is the problem.

Then it might be sour grape for many.
The way Nissan manage the temperature of the battery is by controlling the charging power apply to it with the BMS.
This is another way of doing it, reducing power reduce heating and the need of cooling with whatever means air or liquid.
Of course it’s no help for a fully charged battery left in an oven like environment.
Anybody know the rate of replacement of the Leaf battery?

Djoni asked: “But who would have like to use just 15 kWh of 24 kWh right of the boxes?” Depends on what your aim is. There are still some years left in even the oldest Volts’ warranty, right? It was 8 years? So still 2-1/2 years to go. If, after another 2-1/2 years, it’s still the case that no (or almost no) Volt battery packs are showing degradation in usable capacity due to age, then would be the time to say GM was being overly cautious. In the meantime… I’ll bet it wouldn’t be hard to find a lot of Leaf owners who wished that Nissan had engineered their car’s battery pack to show no loss in usable capacity for at least 5 years! So, the question is this: Which of the following is more important? 1. That the PEV driver be able to take advantage of as much range as he can get out of the battery pack at all times, including when the car is brand new. 2. That the PEV driver be able to rely on his car having as much electric range when he’s had it a few years as it had when it was new.… Read more »

It’s great news…

…however, I still feel some anguish at how GM still is not (openly) putting this tech in all of their mid-sized and large vehicles.

And it pains me to see GM let VIA languish rather than take them over and get the job done. A pickup with no transmission (direct EV drive only)…talk about reliability and super awesome torque for real-world work! And if they did dual motor for 4×4 versions…damn!

I guess we’ll have to wait for Tesla to show people what an electric pickup can do…eventually…

I own a 2017 Volt. It fits my needs nearly perfectly. A couple of things about the GM system. The Volt has a liquid cooled battery pack. This is comparable to an air cooled vs. liquid cooled engine. The liquid cooling advantage is there is a consistent thermal environment for the engine that is not as dependent on the ambient temperature. No hot spots or higher temperatures ranges across the ambient range during operation. One thing a lot of people don’t realize is that GM has ddecades of experience with electric drive and generator systems. Starting with the advent of the submarine systems in the ’30s. GM supplied power systems for them along with marine APU systems in other ships. They also were one of the main leaders in design and technology of early reliable diesel electric locomotives. Basically the same system as the subs of WWII. Those systems were not feasible for a personal vehicle system until technology caught up enough to begin to make it possible. On the locomotives the dynamic braking system is basically the same thing as the regenerative braking on the Volt but instead of converting the electricity into heat through thermistors to be dissipated… Read more »

I think GM is gaming the reliability statistics by not shipping Volts to geographic regions that promote rapid battery degredation. I live in the metro Cleveland, Ohio area, and I just checked, which shows only eight Volts for sale at dealers within 100 miles of my zip code. Four of the eight cars are more than 50 miles away. I have seen only a handful of Volts of any model year on the road in this area in the last few years.

I am waiting with high expectations for the Bolt, and hope it will actually be available in reasonable numbers in tnis area. I am wondering how zero degree Ohio winter days will affect Bolt’s battery capacity. Zero degrees means battery heaters may be needed, there is cabin heat demand, and there is reduction of capacity due low battery temperature.

“I think GM is gaming the reliability statistics by not shipping Volts to geographic regions that promote rapid battery degredation. (sic)”

Wait, what? The most battery issues with the Leaf were in Arizona. There’s many people who have Volts in Arizona and have reported zero degradation.

There’s also people that have Volts in very cold parts of Alaska and Canada, and they work fine too.

GM is not “gaming” distribution. However, they do have a problem with dealer acceptance, likely due in part to the low maintenance of the Volt.

What plug-in cars do you own?

I don’t own any car at all. Not allowed to drive anymore, sadly. The most I can say is that I was able to drive a friend’s first generation (circa 2000) Honda Insight a few times, back when I was still able to drive. That Insight is a stick-shift “combined hybrid” HEV with a powertrain which operates like a (non-plug-in) Prius. Kinda kewl to feel/hear the gas engine instantly start when the stopolight turns green and you shift it from neutral into gear!

I find it sad, and somewhat irritating, to see a few antisocial commenters here express the opinion that I have no right to express opinions about EVs simply because I can no longer drive. Kinda like saying you can’t be a baseball fan if you can’t play the game anymore. Ummmm… no. Doesn’t work that way.

I’ve been hoping to see gasmobiles become obsolete since I was a teenager, and I’m very, very glad to finally see movement in that direction!

Up the rEVolution!

safe to assume the site covered the news some weeks back of about the researcher who discovered a way to make a Li-ion battery experience zero or near-zero capacity loss after 500,000 *full* charge and discharge cycles? IMO the one of the most important steps towards mass adoption.

also, I tweeted it but I’ll ask here as well — any chance you guys might add a discussion forum?

lastly… there’s no way to register so that information doesn’t have to be entered for each individual comment is there? oh and so I could have an avatar too.

You can add an avatar by visiting:

Make sure whatever e-mail address you use to register with there, you enter here as your e-mail address. Otherwise it won’t show up.

Sadly, there doesn’t seem to be any way to avoid having to keep re-entering your screen name and e-mail address here, when you want to post a comment.

I appreciate the info, thank you =)

Do you have the link to the 500,000 cycle no capacity loss research/article?

Thanks for the link. We already have batteries that last “forever”. LTO can do 15-20,000 cycles. That’s 40-50+ years of daily full charges. And they aren’t research lab curiouslities — Toshiba’s SCiB cells have been commercially available for a while (not retail, though).

Mass adoption needs batteries that are even cheaper and lighter. Cycle life has pretty much ceased to be an issue.

I’m at 48,000 miles and 242 mpg lifetime. No degradation here.

My new commute requires me to use 0.11 gallons so I wish there was another kWh available but overall it’s not worth it to change for that.

Some Cleveland / Volt experience. Almost 20K miles after about 31 months. So low mileage. No degradation – it has been hot the past few days and the Volt indicates 52 mile range which is the most it has ever reported. The range does drop to as low as 28 miles/charge in the depths of winter. So Volts are better in moderately warm climates. Tried it going on a couple small cross-country trips of 600 and 1000 miles. Car charging on the road is a bit wacky as most chargers appear to have been subsidized by federal tax dollars and are not well maintained. (About 40% did not work). I guess I understand why some folks key-scratch the sides of EVs out of angry about the federal subsidies. And yes, there are very few Volts about Cleveland. More in California, but still less common than all those generic Tesla boat-cars that are also subsidized? All-in-all, and interesting experiment in government managed technology insertion. It is a good car for me but some guilt about the subsidies. Do we feel guilty about deductions for mortgage interest? I’ve gotto run, I’m off to go key-scratch my vinyl siding.

Comparing a Volt hybrid with the battery electric Nissan Leaf is not a fair comparison. The Leaf battery is subject to much more demanding charge/discharge cycles compared to the battery in the Volt.

There is some validity to your comparison. But the Volt still as similar charge and discharge cycles to a Leaf when using “Normal” mode. This mode discharges the battery the same as a Leaf which will require a recharge, too. In “Hold” mode or when the battery is low the generator will put electricity to the motors through the batteries. The battery still has a reserve because either way the battery provides extra power as a supplement to the engine when going up hills or under higher acceleration. You also have to remember that the Volt has a regeneration system during braking or coasting. This can put anywhere from 0.5Kw to 45Kw or more into the battery. The higher the Kw the higher the current. This will generate a lot of heat in the battery during this cycle. The Volt has a liquid cooled battery system to keep the heat down and to alleviate any hot spots in the batteries, much like a liquid cooling system in an engine. Maybe the Volt has a better battery management system than the Leaf. But, heat is hard on batteries whether it is the charge and discharge cycles or the ambient temperature. I… Read more »

EREV duty cycles are more strenuous than EV. Much higher % DOD and specific currents.

Umm… No. Just no. While I own and LOVE my Volt, I know of multiple people who have had cells replaced in their gen 1 and gen 2 vehicles. Maybe that’s it, “cells” aren’t “[whole] packs”…