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I am strongly considering buying a Volt. I read on GM website. (Q) Battery Capacity over vehicle life. (A) Like all batteries, the amount of energy that the high voltage "propulsion" battery can store will decrease with time and miles driven. Depending on use, the battery may degrade as little as 10% to as much as 30% of capacity over the warranty period.

How concerned should I be about losing 30% in 6 years when I have reached 100,000 miles? Thus reducing a battery range of 40 miles to 28 miles.

Any insights on the subject of battery longevity would be appreciated.

Thank you.
 

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In my opinion, this is the biggest risk factor in buying the Volt or any EV with a lithium-ion battery. The oldest EV with a lithium-ion battery is probably a Tesla Roadster and that's not exactly a representative case since the battery technology there is quite different than for any of the other EVs going into production. Everything else about the Volt is pretty standard technology and will have similar risk profile for reliability as systems on any other car. I took the risk because I told myself I would never buy another car that didn't plug in and it was time for us to replace one of our cars. Of the two options available (Leaf, Volt), the Volt seemed the best choice. We'll see.
 

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The Volt battery is 16 kWh but only 10.5 kWh of that capacity is used for propulsion. You will see no loss in range as ample margin has been built in to accomidate gradual degradation in battery capacity over the guaranteed battery life .
 

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From my understanding, the degree of battery degradation will depend on how you use the car, including how much you drive on the battery power alone, and whether you live in a very hot climate.

100,000 miles in 6 years is 64.1 miles daily @ 5 days/week so if you want to be doing that on all electric you are going to have to charge more than once daily. E.g. if used for commuting, at both ends of the commute.

If you drive on gas a proportion of the time, you will have run the battery through fewer charge/discharge cycles and it probably will have less degradation simply because it hasn't been used as much (I'm not recommending intentionally driving on gas).

Currently, I understand, the battery is $3000 to replace. The price is dropping rapidly. But even in worst case scenario, if your battery is totally useless at the end of 100,000 miles it would be like replacing a transmission on a regular car.

And potentially in 6 years the price will be half or less that the current price, and modifications to the Li-ion chemistry may be providing substantially longer life for the batteries. Perhaps even the current battery will be able to be retrofit with battery chemistry updates. That is purely me being theoretical.

So if you live in a very hot climate like Arizona, always park your car out in the sun, do most of your driving on the battery power (not the range extending generator), I think that might contribute to your battery having more like the 30% degradation.

To me, I really don't get the concern here: as I have posted elsewhere online, the average american keeps their car for 5.5 years. So somebody who buys a premium segment car such as the Volt is pretty likely to want to upgrade to the latest and greatest in 5 or 10 years. Even if not, if I'm spending $40,000 on a car that is way better than any BMW or Lexus (IMHO... I see no real-life benefit of these expensive cars over my current ICE clunker.... really just a status symbol, quite meaningless to me), spending even $3,000 on a brand-new power source in 100,000 miles is not really a big deal. Sure it's a chunk of cash. But it's less than 10% of the car's new cost. And as I say, I suspect the price at that time might be far lower, and the replacement far better than even the current excellent battery tech.
 

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Battery life is definitely the biggest risk in an EV, and actually one of the reasons I bought a volt over a pure EV.
Since I have a range extender, if I start loosing range it becomes a financial tradeoff of replacement vs burning gas. In any other EV, it becomes a question of can I get where I needed (and used to be able) to go.

The Nissan leaf has a much weaker statement:
Lithium-Ion Battery Gradual Capacity Loss:

The Lithium-ion battery (EV battery), like all lithium-ion batteries, will experience gradual capacity loss with time and use. Loss of battery capacity due to or resulting from gradual capacity loss is NOT covered under the Nissan New Vehicle Limited Warranty. See your Owner’s Manual for important tips on how to maximize the life and capacity of the "Lithium-ion battery.” (See your Nissan dealer and read the actual limited warranty for complete details).


All batteries can and will degrade with time as well as miles. While they have done various accelerated testing on the batteries, no one knows exactly how it will last. We'll know in 15 years. But its an easily replaced module, for which the current GM replacement price seems to be 3K-4K for the parts.

Temperature and agressive charging are the real killers, a hot overchraged battery degrades fast. But the volt only uses the middle section of the charging cycle (which is the easiest on the battery) and Since GM has active Temperate Management I expect the batteries to do well for the long term.

If in 10 years I'm only getting 28m in the summer, and everything else is doing well, I'll have the option to replace the battery, just burn a bit of gas if needed (I should be retired by then) or sell it as a used car that still runs well.
 

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How concerned should I be about losing 30% in 6 years when I have reached 100,000 miles? Thus reducing a battery range of 40 miles to 28 miles.
Zero. GM warranties the RANGE for 8 years and 100,000 miles. It is also going to warranty the battery in CA for 10 years 150,000 miles and it doesn't appear that it is going to charge a premium for this.

You might see a range of 28 miles after ten years but at some point the car is approaching EOL.
 

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Zero. GM warranties the RANGE for 8 years and 100,000 miles. It is also going to warranty the battery in CA for 10 years 150,000 miles and it doesn't appear that it is going to charge a premium for this.

You might see a range of 28 miles after ten years but at some point the car is approaching EOL.
Not sure about that. The way I read it is a warranty on capacity but that is not precisely defined as range.
Since range can change as a function of driver, I can imagine (hope) there being some more standard test than the owners mileage. And it would have to adjust for temp changes since the temp swings can be more 10%.
 

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>> Currently, I understand, the battery is $3000 to replace.

Is this verified by GM at a dealership? I think it's currently only a "rumor" that a full T-pack replacement is $3K. I think the rumor is based on the expected future-cost at the end of the 6-8 year life of the initial OEM battery rather than a "today" cost of replacement.

Maybe Trevor or someone from GM could confirm? This keeps coming up and is markedly low compared to the costs spoken of only a year ago of $10K. Right now, all packs replaced are done so under warranty, so nobody (that we know) is writing a check for one yet. But it would be an interesting question to get answered and reviewed here.

Someone here got quoted by a dealer at $4100 for a pack replacment after a stone went through their TMS radiator and coolant leaked out leading to a battery that got "hot" (so said the dealer). Did that get resolved under warranty?
 
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Found this article really interesting. It Deals with the recycling of the High Voltage Battery years from now, after its usefulness in the Volt. Might just result in a bidding war ! Utilities nationwide will buy these battery packs up and warehouse them-using the 50-70% usability left, for off peak grid electricity storage !

Other uses for home, business and other Distributed Energy points are in review as well.

"Earlier this year, General Motors signed a definitive agreement with ABB Group to identify joint research and development projects that would reuse Chevrolet Volt battery systems, which will have up to 70 percent of life remaining after their automotive use is exhausted."

Does the above quote from the linked article below indicate a 10, 15 to 20 year usable life potential?

Link:

http://media.gm.com/content/media/us/en/gm/news.detail.html/content/Pages/news/cn/en/2011/Jul/0722


------------------------------------------------------------------------------------------
The Amazing Chevy Volt EREV-Facts Guy

Wating for rollout of Dow Powerhouse Solar Shingles and paying down new high efficency furnace. Wating for 1st Cyber Grey Allocation/ Spring 2012!!

gm-volt.com/forum/showthread.php?9525-The-Volt-White-Paper

Reloaded: December 8th 2011
 

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I remember an interview on Autoline Detroit several years ago after the Volt was first announced. The GM spokeswoman saiid it was their intention to design the Volt in such a manner that it will provide the 40 mile range even at the end of battery life.
 

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I think the battery degrades 15% - 30%. After the 8 years you'll have a range greater than the new plug-in prius or plug-in accord batteries. For me, its a non-issue.

MrEnergyCzar
 

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All batteries can and will degrade with time as well as miles. While they have done various accelerated testing on the batteries, no one knows exactly how it will last. We'll know in 15 years. But its an easily replaced module, for which the current GM replacement price seems to be 3K-4K for the parts.
Easily replaced is a relative term. The battery is big and heavy, and is removed by lowering it with the vehicle hoisted. There are numerous electrical and coolant connections in a tight space. Replacing a battery would be similar to replacing an engine - several hours of labor time, at a dealership average labor rate north of $100/hour.

That being said, a senior Volt engineering executive told me at the Woodward Cruise event dinner that in Michigan, without the hot blacktop summer soaks, the expected battery life is 16 years. This is not meant to be any claim. But GM does have the largest battery testing lab in the world, and the last I knew, the very first prototype LG Chem battery is still being cycled, with multiple charge / discharge cycles per day. Temperature excursions are also done repeatedly as part of the accelerated life testing, which was begun years before start of production. There are many well-known and commonly used reliability techniques that use accelerated life test data to accurately predict B-90 life (the point at which 90% of the units will survive).

As mentioned, the Volt (unlike the Leaf) has an active thermal management system, with liquid battery cooling (including chilling from the A/C when necessary) for long battery life, and heating of the coolant when necessary for battery / vehicle performance in cold weather. Also, the Volt does not need to go deep into the battery state of charge toward the end of its EV range; the ICE simply turns on. This is not true of the Nissan Leaf. They limit performance when the battery gets hot. Leaf drivers who habitually drive to near zero range will be stressing their batteries. Their saving grace may be that their owners don't put a whole lot of miles on their Leafs (unlike me, who has 21,162 miles on my Volt since April (8,118 EV miles). Nissan tells you that if you have a Leaf and want to make a long trip (or drive it when it is very cold), you should either rent a car or have a second car to drive under these conditions.
 

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The Volt battery is 16 kWh but only 10.5 kWh of that capacity is used for propulsion. You will see no loss in range as ample margin has been built in to accomidate gradual degradation in battery capacity over the guaranteed battery life .
You are suggesting that the charging system will extend it's use of the pack as it ages but I have not seen anything from GM that says this is so. Lyle mentioned it in a post once. That's the closest thing I've seen to a reference.
 

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Well, it would be that the total 16kWh will diminish but the 10.4kWh "allowance" should still be there. Allowing for 40 miles in 70*F summer even when the total capacity is diminishing. The total capacity may dip to ~14kWh if a full SOC recharge from "dead" (3.0V per cell) were to be done. If the capacity limiter logic (low voltage and high voltage sum-total) works as it should, there may not be a decrease in mileage available even though total capacity is slowly dropping.

I have to wonder how much heavy regen braking and acceleration (city/taxi style) would differ in pack aging over stead-state highway driving.

Leaf owners who can use much more of their available SOC should see it more apparently. And they'll need to access more of that SOC range after a few years.
 

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Easily replaced is a relative term. The battery is big and heavy, and is removed by lowering it with the vehicle hoisted. There are numerous electrical and coolant connections in a tight space. Replacing a battery would be similar to replacing an engine - several hours of labor time, at a dealership average labor rate north of $100/hour.
I don't think that's entirely true. The battery is much easier to replace than an engine. I think they can do it in an hour or so.
 

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You are suggesting that the charging system will extend it's use of the pack as it ages but I have not seen anything from GM that says this is so. Lyle mentioned it in a post once. That's the closest thing I've seen to a reference.
I've seen this too and I believe it is the case. The software is monitoring how much effective capacity gets extracted in a full charge cycle, so it's not surprising that they would take advantage of opening up the SOC window to help ensure capacity available remains consistent throughout the vehicle's life.
 

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I believe the buffer that's built into the battery is progressively tapped into as the life goes on, so that the available kwh is about the same until the end of the 8 years. So at the end you'll still have the same range, but the battery will be draining almost completely instead of maintaining a smaller SOC as before.
 

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I don't think that's entirely true. The battery is much easier to replace than an engine. I think they can do it in an hour or so.
Yeah, engine R&R in a normal vehicle is a massive undertaking involving removing all those electrical connections, fuel lines, disconnecting the motor mounts, disconnecting the transmission, etc etc etc. Not the same
 

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I had dinner sitting next to Andrew Farah. He is the chief engineer for the Volt. One of my many questions was about the useful battery life. He answered with the question of "where". He explained that there is a difference depending on whether you use your Volt in Detroit or Phoenix. These batteries don't like heat. In Detroit's climate he said that we can expect a minimum of 15 years, 12 in Phoenix. He also added that all is not lost as GM is working on a box that can be set in your yard with circuitry to allow your old Volt battery to be used as emergency power for your home. He said that it would run your house for at least 48 hrs. The battery wolud be enclosed in the box and you would wire it just like they do for standby generators. I have always felt that a gas or diesel standby generator was useless because if you don't have electricity, neither does the gas stations. You won't be able to refill your fuel supply. A natural gas generator makes sense if your home has the stuff. An old Volt battery would work very well.
 
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