Chevy Bolt EV Forum banner
1 - 20 of 29 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
I rec'd a notice from GM about a month ago that they were ready to replace the battery in my 2019 Bolt. After replacement, I called back to see what the warranty coverage is with the new battery. The dealer looked up my Bolt by VIN number and said that the mileage had been extended by 80K to about 94K but the warranty will run out at 8 years from the date of purchase. :-( I got an extension of mileage, but not of the time. It was my understanding that we would get 8 years and 80K from the date and mileage of the replacement. Have any of you seen anything official from Chevy that says we'll get extended on both mileage AND time? THNX
Loring
 

·
Registered
Joined
·
393 Posts
The GM website states this, the 8 years and 100K miles start at the time of installation of the new battery. Your dealer is not correct. Just keep your receipt from the battery swap and the record of the mileage at that time.

General Motors warrants new or refurbished advanced propulsion batteries installed under this recall against defects in material or workmanship for the warranty coverage period of 8 Years/100,000 Miles (whichever comes first). GM will repair or replace the part, in its sole discretion, at no charge if the part fails due to a defect in material or workmanship during the warranty coverage period (Note: Labor is also covered if installed by a GM EV Dealer). This limited parts warranty begins at the time of installation.
 

·
Registered
Joined
·
1,037 Posts
The GM website states this, the 8 years and 100K miles start at the time of installation of the new battery. Your dealer is not correct. Just keep your receipt from the battery swap and the record of the mileage at that time.

General Motors warrants new or refurbished advanced propulsion batteries installed under this recall against defects in material or workmanship for the warranty coverage period of 8 Years/100,000 Miles (whichever comes first). GM will repair or replace the part, in its sole discretion, at no charge if the part fails due to a defect in material or workmanship during the warranty coverage period (Note: Labor is also covered if installed by a GM EV Dealer). This limited parts warranty begins at the time of installation.
I don't see degradation covered in that snippet
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
I don't see degradation covered in that snippet
That is an interesting catch. Does this limited warranty supersede the original battery warranty or is it additive? By that I mean the parts of the original warranty that aren't repeated, I know the duration starts from install time/milage.
 

·
Registered
Joined
·
3,355 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #6 ·
cwerdna:
The snail mail letter from Chevrolet is/was very helpful!
Note that this version of the warranty adds a 100K warranty and the source is the National Highway Transportation Safety Administration. :). WOW!
THNX!
 

·
Registered
Joined
·
3,355 Posts
Well, the source is GM, who uploaded it to NHTSA's site. You should've received the snail mail.

GM has also referenced in numerous places like (search them for warranty):

And, it's all over the press if you search for stuff like bolt recall 8 year warranty.
 

·
Registered
Joined
·
1,616 Posts
That is an interesting catch. Does this limited warranty supersede the original battery warranty or is it additive? By that I mean the parts of the original warranty that aren't repeated, I know the duration starts from install time/milage.
Did GM ever cover degradation? I know they said early on that degradation "up to 40%" could occur during the warranty period but that's not exactly the same as saying they'll replace the battery if you have 41% degradation within 8 years/100k miles.

In any case, I would think it'd be deduced that whatever the original warranty covered would be covered here unless stated otherwise.

Mike
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
Did GM ever cover degradation? I know they said early on that degradation "up to 40%" could occur during the warranty period but that's not exactly the same as saying they'll replace the battery if you have 41% degradation within 8 years/100k miles.

In any case, I would think it'd be deduced that whatever the original warranty covered would be covered here unless stated otherwise.

Mike
By putting it in the warranty they have to remedy it. Since they stated a figure of how much degradation could occur normally anything above that figure would be considered a failing defect, within the warrantable time period of course. Now how they remedy it is up to them and it would only need to get it back within their already state acceptable range. So maybe they would just replace the lowest or perhaps lowest two modules to get the battery to show less than the 40% degradation. Or maybe they would replace the whole pack. I certainly can't say for sure, but since they state allowed figures they have set an expectation of what is normal versus abnormal.
 

·
Registered
2021Bolt
Joined
·
701 Posts
maybe they would just replace the lowest or perhaps lowest two modules to get the battery to show less than the 40% degradation. O
I will bet it will be very hard to pin down and prove something greater then 40% degradation with the GOM data.
Maybe GM might accept KW data from a app. But with resistance. It will probably have to be more then 47.6% (my GOM) to get any actions taken.
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
I will bet it will be very hard to pin down and prove something greater then 40% degradation with the GOM data.
Maybe GM might accept KW data from a app. But with resistance. It will probably have to be more then 47.6% (my GOM) to get any actions taken.
Well i'm certainly not saying GM would make it easy on anyone. However with an OBDII reader and the right codes you can see the exact capacity of the battery that is reported by their own software/hardware. Just out of curiosity I just went and checked my Bolt again, haven't looked at it in awhile. Mine currently shows a battery capacity of 53.8 kWh.
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
Every single EV manufacturer are very clear in stating that pack degradation is normal and is NOT a manufacturing defect. If the manufacturer does not explicitly include a degradation warranty, it does not exist and it is not implied.
Who said manufacturing defect? I know I said a battery that degrades above their stated figures would be considered a defect and you would be entitled to a remedy. That doesn't imply a manufacturing defect though, it just by their own stated performance figure that battery has failed thus can be deemed a defective battery. It doesn't mean the entire battery is defective, could be a single module. There have been many posts on here where members have had to get single modules replaced because they failed.


However if you are saying since GM doesn't say the words battery degradation warranty thus they don't have one, you would be incorrect there. If a manufacturer states an acceptable level of degradation in their battery warranty then they are going to be held to that. Of course only within the warranty period of course.

Electric car battery warranties compared
Comparing Battery Life of Top Electric Car Brands | EnergySage
Tesla now covers degradation in Model S/X warranty — but leaves software loophole

Those are just a few of the links that came up with a simple search.
 

·
Registered
2021Bolt
Joined
·
701 Posts
software/hardware. Just out of curiosity I just went and checked my Bolt again, haven't looked at it in awhile. Mine currently shows a battery capacity of 53.8 kWh.

At first I though the mx link was busted as could not see the led’s in sunlight. But I just forgot to set up the Bluetooth. I keep the dongle in the center console under the arm rest. Was thinking it overheated. But it’s good
Have not checked mine in 2 months so you inspired me to check

The 2021Bolt show like 63.4KwHr.
And like 189.4amp hrs as I recall.
I use the MyVoltcontrol app.

At first I thought the MX link overheated and was not working but I just could not see the led’s in sunlight
 

·
Super Moderator
2020 Chevrolet Bolt
Joined
·
3,537 Posts
Enough with the misinformation. There is an Ah PID that GM uses. 40% degradation is the standard, which is worse than some other automakers. Some posters (prior to the recall) have had their batteries replaced under warranty based on that standard.
 

·
Registered
Joined
·
4,564 Posts
There is an Ah PID that GM uses. 40% degradation is the standard, which is worse than some other automakers. Some posters (prior to the recall) have had their batteries replaced under warranty based on that standard.
From the examples I've seen, replacements haven't been done due to degradation. It's been due to a cell or two having an imbalance/failure, which shows up as a relatively sudden loss of capacity. Degradation is a steady, mostly linear, decline over time (and cycles), affecting all cells uniformly. Either way, the warranty covers up to 40% loss of capacity.
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
Have not checked mine in 2 months so you inspired me to check

The 2021Bolt show like 63.4KwHr.
And like 189.4amp hrs as I recall.
I use the MyVoltcontrol app.

At first I thought the MX link overheated and was not working but I just could not see the led’s in sunlight

Been about the same amount of time since I last checked, kinda stopped caring to watch it since I knew we were getting new batteries. I'm sure once I get that new battery i'll start checking and logging regularly just to watch.
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
From the examples I've seen, replacements haven't been done due to degradation. It's been due to a cell or two having an imbalance/failure, which shows up as a relatively sudden loss of capacity. Degradation is a steady, mostly linear, decline over time (and cycles), affecting all cells uniformly. Either way, the warranty covers up to 40% loss of capacity.

Sudden imbalance, failure or really anything in the battery that causes loss of capacity is a form of degradation. Degradation does not mean it has to be steady and linear. The word degradation is quite often used to describe how li-ion batteries will slowly over time lose part of their initial capacity and typically the experience is gradual. Instead of spelling out the process and reasons why this occurs as it is entirely too technical for typical consumers. However that is just one form of degradation. Degradation can absolutely be used to describe a sudden loss of capacity.

Now I understand the point you are making, in that you are not aware of anyone who has had replacements due to the typically slow and gradual loss of capacity li-ion batteries are going to experience, and I would agree with that assessment. I am not aware of any cases where it has been from the expected slow gradual loss of capacity.

Barra herself made a similar statement a few years ago, GM even had to clarify what they meant because she made a pretty blanket statement that taken on face value was incorrect.
UPDATE: Mary Barra Says GM Has Never Replaced A Volt Or Bolt Battery
 

·
Registered
Joined
·
4,564 Posts
Degradation can absolutely be used to describe a sudden loss of capacity.
I just think it could be very misleading for those without a thorough understanding. If you start yelling about your battery having 50% degradation in a 2 year old car, the layman will assume that this is just something that happens to all batteries because they've been told that all EV batteries suffer from degradation, which is true. So to be clear, I think we should talk about "normal" decline of capacity as degradation and sudden decline due to defects as a loss of capacity, or sudden degradation due to defect/imbalance, or something to indicate that it is not something normal and expected.
 

·
Registered
2017 Bolt Premier
Joined
·
1,368 Posts
I just think it could be very misleading for those without a thorough understanding. If you start yelling about your battery having 50% degradation in a 2 year old car, the layman will assume that this is just something that happens to all batteries because they've been told that all EV batteries suffer from degradation, which is true. So to be clear, I think we should talk about "normal" decline of capacity as degradation and sudden decline due to defects as a loss of capacity, or sudden degradation due to defect/imbalance, or something to indicate that it is not something normal and expected.

I don't completely disagree, I mean I did say I agree with the point you intended. I only said anything because the use of the word degradation doesn't just mean the gradual loss type. Some EV manufacturers don't even use that word, some just say loss of capacity or remaining capacity. It is really a catch all saying we warranty your battery to have this much capacity for our stated warranty period.

I also understand that colloquially with batteries the assumption is degradation means slow loss because that is by far the most typical pattern observed.

The other reason I said something is since it deals with the warranty and legal obligations, the use of the words and their definitions really matter. In this case the cause, be it typical slow loss or sudden loss, degradation applies to both in that GM would be responsible to fix it.
 
1 - 20 of 29 Posts
Top