BoBattery failure - How good is the warranty going to be?

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willeert

Member
Joined
Jul 6, 2017
Messages
12
A few weeks ago we were coming home in our Bolt. The State of Charge meter was indicating 25% full. The vehicle gave us a low power remaining / propulsion power reduced warning and slowed the car. The SOC bars turned orange and black and started to disappear. Within 3 Km we were dead beside the road with the battery indicating 0% SOC.

After looking on this forum it was apparent that there was a Customer Satisfaction Program #18097 out on the Bolt to reprogram the hybrid powertrain control module 2. We took the car in and had this done. When we got the car back it was much different. Our SOC meter was reading lower and the guess-o-meter range was much reduced. I could not figure out where all the energy went to while the car was in the shop.

On our way home we stopped and charged the car fully with hilltop reserve off. We set off down the highway and started taking readings. The car averaged 2.37 Kwh per 5% of the SOC meter. Prior to going in the shop it had always averaged around 3 - 3.1 Kwh per 5%. This explained the loss of SOC and suggested range following the recall update. The car was telling us that the battery capacity was now 47.5 Kwh. If the new capacity is 60 Kwh then our battery is down 21% in capacity. We contacted our dealer, sent him the data and suggested that they should start looking at a warranty battery to restore our Bolts battery capacity to what one would expect for a car with 12,000 Km / 6700 miles on it. We heard nothing back from them.

We ran another test on our battery capacity a few days later. This test indicated each 5% is now worth 2.19 Kwh which calculates out to a total battery capacity of 43.9 Kwh. The battery continues to diminish in capacity and is now at 27% loss of capacity. I contacted the dealer again and gave them the new data. They have escalated the problem to GM Canada and are waiting to see what happens.

We live in Manitoba and this 1 of 2 Bolts in the province. I have a lot of faith in the dealer and feel they are doing what they can for me. I read that GM can diagnose battery problems via OnStar and have suggested to them that if this is possible that it be done. So far GM Canada seems (and it could be a bad perception) to be doing little to help the dealer out. I read of others getting replacement batteries and our Bolt is telling us our battery has lost capacity and is continuing to die.

So the question is - How does GM decide to replace a battery? How do they make up their minds a battery is failing and requires replacement? WE do not want to continue driving our car and watch the battery capacity reduce until we are dead by the side of raod again. We like our Bolt and enjoy driving it. This is a newer technology and one would expect a few problems. One would also expect that the Producer be very responsive in a timely fashion to the problems however.

Will
 
You can read more about the battery software updates here:

https://electricrevs.com/2018/05/10/gm-releases-new-round-of-updates-for-all-bolt-evs/

Read about the details of the underlying battery cell problem here:

https://electricrevs.com/2018/04/02/new-details-emerge-as-a-few-bolt-ev-packs-continue-to-fail/

If your battery went immediately from 25% full to orange low battery warning and reduced propulsion then you may have a weak cell which requires a pack replacement.

If you are technically savvy (or have a techie friend) you can find the details in the above article about how to see the individual cell group health using a cheap diagnostic tool and smartphone software.

Your GM dealer should be able to do this using their own diagnostic tools.
 
willeert said:
How does GM decide to replace a battery? How do they make up their minds a battery is failing and requires replacement?
The car's onboard software reports issue like this to GM directly - they've been contacting people with problematic batteries to arrange for replacement.

The updated battery software has been known to cause wonky range estimates, it may take a charge cycle or two for things to settle down. Meanwhile, it sounds like your dealer is following up for you - at this point you'll just have to wait and see what they come back with. But if your range continues to be suspect and you don't hear back from them in a timely fashion, then by all means escalate the issue!
 
This not a range issue - although the indicated range is reduced. The issue is battery capacity. I think what I am up against is the fact that I live in Manitoba. As I understand it GM has the policy of not selling Bolts in areas that do not give a rebate of some kind to purchase one. Manitoba gives no rebates. We were able (and happy to do so) to purchase a Bolt from a Chev dealer in Winnipeg who had obtained one for a purchaser that could not take the car. They are not a certified Bolt dealer as such. I suspect that there are special tools that permit diagnostic functions, such as determining battery capacity, to take place that my dealer may not have. This would explain the "pause" that I am encountering with my battery problem.

It seems from the feedback I am getting here that if a battery pack is determined to be failing it gets replaced. The Bolt is telling me - based on Kwh used per 5% SOC that the battery pack capacity is far from design capacity and it is failing.

I am electronically handy and have reviewed the links that JeffN posted (Thanks Jeff). I can buy the equipment and do self diagnostics on the battery pack. I do not think that this is the route that a customer should have to take however. Even if I self diagnose the battery sooner or later the car will have to go into the dealer and they will have to do the diagnostics for themselves.

Oh well - Hopefully GM Canada will take my problem seriously and do something. At this time I feel like so far they are not understanding my woes. I am certainly not in a position to give up with this problem. We still enjoying the car but we bought it because of the range given by the battery capacity. We live in the country and our nearest town is a 120 Km round trip. At -25C with the winter reduction in range the car would give range anxiety making it town and back as it is now. 1 in 1000 failures and 1 of 2 Bolts in Manitoba....

Will
 
I continue not hear back from Chevrolet about my Bolt's lack of battery capacity problem. Although I resent having to do it I have set myself up to get battery data from the OBD2 connection. I had to load a very invasive Bluetooth emulator program into my PC and purchase TorquePro. I also needed Astro file manager to be able to transfer the PID csv file into TorquePro and set it up. All done. I ordered a Bluetooth OBD attachment and after it arrives I will know the state of my battery groups. One would have hoped GM Canada had more interest and customer support for someone who bought a vehicle from them. Disappointing.

Will
 
I heard back from my dealer 2 days ago and we had a phone discussion yesterday. I am pleased we are moving forward. We discussed the Bolts symptoms and why I believe that the battery needs diagnosing. They stated the first step of diagnosis is to bring the vehicle in and leave it overnight. They will give me a loaner rental vehicle. I live about 2+ hours away so will get the Bolt in to them next week. I suggested that others had this problem diagnosed using OnStar however that is not an option in this case.

I have the Torque Pro program reading data from the Bolt OBD2 port. I had to buy an android device in order to pair the Bluetooth OBD 2 adapter with Torque Pro. Bluetooth emulators do not hace this capability.

The battery is fully charged at this time. I can see that cell 29 has a voltage of 3.86 V while most o the rest of the pack is at 4.13 to 4.15 V. Six other cells are in the 4.12V range. I attempted to attach the excel file of the data to this posting but the file extension not recognized???? Also couldn't get a .pdf to work... More stuff I don't understand. If anyone can point me to the correct method of attaching files I am happy to show the data.

Everything I read indicates that my Bolt battery has failed. Hopefully, after going through the reset procedure, GM will realize that also.

I am glad and do feel more positive towards GM now that they are responding to my concerns. The Bolt is a nice car and GM does not make the battery packs.

Will
 
The Bolt went into the dealer and had the "battery capacity reset" procedure done. It stayed overnight while this happened. After the procedure the service manager and I took a set of readings on the car using the torque - pro to get the data from the OBD2 port. On my way home it was noticeable that the battery capacity had been reset - it was much lower. My battery capacity, based on KwHr used per 5% of the State of Charge meter now calculates out to 38.57 KwHr! Not good.

Gm has reached out to me and we have had a few phone conversations. I have sent them my emails to the dealer and also some data sets on the car. I am pleased that GM is reaching out as part of reaching resolution on this problem.

The dealer has requested that the car come back in and they will perform actual battery tests now. They wish to "drain" the battery, recharge it and then take a set of their own readings. This also a good thing I suppose. It is easy to be critical of organizations however it seems to me that GM has finally realized there is a problem with this car and that it needs to be repaired. I am booking the car in for the required testing next week and hopefully that will get us a decision on what the solution to the battery capacity loss is.

Good things are that my Chevrolet dealer has become a Bolt dealer now. This means they should have all required expertise and equipment to work on this car. It is also good that they are taking seriously my loss of battery capacity problem. I am glad that GM has reached out to me.

Irritations are that we live 2 hours away from the dealer. Each overnight visit means a minimum of 8 hours in the car over 2 days. This is part of living where we do. I also wish that there was a one stop procedure for diagnosing battery problems. These repeated trips to drop the car off and pick it up again are taking a lot of my time. Hopefully as GM gains expertise with these vehicles procedures will become more organized.

Will
 
Thanks for the updates.
I’m 90% sure you will get a whole new battery pack.

I live in California and got my Bolt in Feb. 2017.
(I think it was a December 2016 built car.)

Mine was driving fine. No loss of range or warning messages.

Chevy customer care called me out of the blue telling me my car needed a whole new battery. It took 12 days for the new battery to arrive and they installed it on the 13th day. I had a free loaner car (100% gas) for 13 days. I thought my car was fine but they did not want me driving it even though this is Silicon Valley and there are charge plugs on almost every street.
 
So my Bolt went back to the dealer for actual battery capacity testing. It had to stay overnight. They gave me a loaner rental car.

Next day - The dealer service manager communicated that the battery testing was completed and that cell 29 voltage indicated a problem. He said they were communicating with GM and would let me know. The car stayed overnight again.

Next day - The dealer communicated that GM had approved a new battery for my Bolt. It is due at the dealers mid next week and will be installed at that time. Yay!! Resolution.

So given that my car is one of two Bolts in Manitoba and that the dealer is unfamiliar with them I think they did OK. Once they realized that the problem was not a range problem but a loss of battery capacity problem they did a lot better. I am pleased how quickly they seem able to get a new battery. Now to get my car back and see if it is fixed.....

I am a lot happier.

Will
 
The Bolts new battery has arrived at the dealer. They have sent me lots of images. Very interesting for me. It is a brand new battery with the new style of cooling connections. GM customer care has been contacting us periodically to ensure we are informed and comfortable with what is going on. In conversation with my wife they offered to cover the gas and insurance cost of the rental vehicle the dealer provided.

I don't know what more one could expect from a car company and dealer than what is happening with us. Given that the failure occurred and that GM does not make the battery pack they have been very good.

Our car may be ready to be picked up tomorrow. It is good driving the Chevrolet we have been given but we do like the Bolt better.

I will post some of the images if I can but the files are too big for this site. I will have resize them to post.

Will
 
I've just had almost the exact same thing happen to my Bolt as Will. I've had my Bolt since May of 2017 and it has almost 28,000 miles on it now. It's capacity had fallen from 60kWh to around 58kWh, based on the energy used indicator and the SOC, which seemed pretty much as expected.

I then went to the dealer yesterday and had the software updated to address the recall, and I realized today my battery's capacity had fallen to 43kWh. I've attached a picture of the dash to illustrate this. Of course I found this out on my long commute from the Toronto area to Buffalo and was thinking I won't even be able to drive to work and back once it gets a little colder.

Hopefully GM will give me the same good treatment, I plan to call the dealer on Monday and go from there!
 
PhilK said:
I then went to the dealer yesterday and had the software updated to address the recall, and I realized today my battery's capacity had fallen to 43kWh.
The update resets some parameters that are used to track battery charge and usage, and this can have a noticeable effect on the reported figures - especially if the battery wasn't full when the update was done. It should go back to normal after a few charge cycles, so you may want to hold off a bit before crying wolf to the dealer.
 
I brought my 2017 Chevy Bolt into the dealer in December 2018 for recall 18097.

I am not as conversant as other members of this forum with the precise terminology, but in essence, when I got the car back the range after full charging was only 160 miles rather than around the 238 rating for the Bolt.

A technician at the dealer told me that the range had not actually been reduced but that the battery has to "relearn" my driving and that after 10 driving cycles, it should be restored.

I don't drive that far and after one year only have about 3400 miles on the Bolt so I fear it might take forever for me to get a true reading of my range.

After a month of driving around, the range after full charge is even lower, around 156.

So I think that the statement that my car has to "relearn" my driving is complete B.S.

I have complained to GM and was told, in essence, to pound sand.

For technical reasons, the Lemon Law in NY is not available to me so my only alternative is to sue GM.

Does anyone have any suggestions?

Thanks
 
clustgarten said:
I brought my 2017 Chevy Bolt into the dealer in December 2018 for recall 18097.

I am not as conversant as other members of this forum with the precise terminology, but in essence, when I got the car back the range after full charging was only 160 miles rather than around the 238 rating for the Bolt.

A technician at the dealer told me that the range had not actually been reduced but that the battery has to "relearn" my driving and that after 10 driving cycles, it should be restored.

I don't drive that far and after one year only have about 3400 miles on the Bolt so I fear it might take forever for me to get a true reading of my range.

After a month of driving around, the range after full charge is even lower, around 156.

So I think that the statement that my car has to "relearn" my driving is complete B.S.

The "estimated range" is just that - an estimate, taking into account your driving habits and other factors. It is NOT a 'pure' measure of the capacity of your battery.

Yes, the software DOES have to "relearn" after the update for the "estimate" to be more accurate. Now, that doesn't mean everything is great, OR that anything is wrong.

If you have the charging pref of vehicle set to use "hilltop reserve", your range estimate will be lower (because you are only charging the battery to about 90% and not "completely full").

Range is also influenced by temperature - if you drive 160 miles in the exact same way and using the same route, you will get more range at 75 degrees than at 35 degrees - so winter does figure into a lower range estimate.

If this magic number of "range estimate" is important to you, I would take the car out for a drive on a beautiful day, and : (1) leave with a 'full' battery (even "full hilltop reserve"), and (2) use a route so that you drive you through beautiful countrysides at about 45-55 mph, and (3) do a drive that is about 80% of the estimated range when you leave (for safety sake). Then, when you get back let the vehicle completely recharge overnight. That should go a long way to re-calibrate your range estimate.

Good luck!
 
Thanks so much for the suggestion.

So you don't think I have a beef with GM. I should just do the long drive you suggested and see what happens?

Chet
 
I don't think that you have enough information (data) to know if you have a beef with GM or not.

The range estimate is just an estimate. Does your gas mobile tell you how many miles you can drive on 5/8ths of a tank of gas?

When they did 'whatever', they either unplugged power from everything, OR as part of the update they 'crushed' the old info, and it looks like the computers 'forgot' about range - so the car has to relearn.

If you go on a long drive, and the estimate doesn't change - then I'd be a *little* worried. I would, in fact, plan several trips to take into account "what if" : "what if" the battery goes too low and I am too far from home?, for example. So I would fill up the battery. If it shows (say) 150-mile range, I would plan a trip that got me near home after about (say) 120 miles. After I got back from that drive I'd look at how much battery is remaining, and go for a drive that was 3 miles for each bar (minus one) remaining (i.e., if 4 bars remain, 3x5=15 miles. If 8 bars remain, 7x3=21 miles.) That way you are close to home if/when you get really low on electricity. Personally, I wouldn't want to get much below 10% battery remaining if I were much more than 5 miles from home. That should get you close enough to "not much battery left" for the car to realize how far you can go on 'a tank'.

You do know that there are "5% capacity" bars on the side of the display, that show capacity of the battery (in 5% increments) - right?

maxresdefault.jpg




The above image shows that the "guess" of range is at 75, with a min (estimate) of 61 and a max (estimate) of 92. The green portion to the left shows that the battery is half full (ten bars, 10x5% = 50%) .

The below image shows that you are getting low on range (bars are now orange) and that about 15% of the battery charge remains (3 bars).



DSC_6227-marked.0.jpg
 
Thanks so much for the explanation but I am still puzzled.

There are two scenarios, it seems to me. One is that the battery was damaged as a result of the recall and it really has only the range shown.

The other is that there has to be a "relearning" process.

According to the technician at the dealer I spoke to, I would have to go through 10 drive cycles for the battery to complete its relearning process. Although I am a technologically oriented person, the concept that the car has to "relearn" makes no sense to me. I only had it a year when I brought it for a recall and it had only 3000 miles on it. What did it "learn" during that time?

The technician told me that a drive cycle would be one where 60 Kwh (out of 74) are used. Assuming 2 miles per Kwh, that means 120 miles. So I would have to drive 120 miles on 10 occasions. That will never happen.

You are suggesting that I take one long trip of 120 miles (if the range is 150 miles). After doing that, what will show me which scenario applies?

By the way, I did not know about the green bars representing 5% of capacity. There is a lot about the Bolt I have had to learn and am still learning. When I drove it home from the dealership for the first time a year ago, I knew very little (but probably more than the salesman who sold it to me).

My attitude was and still is that GM is at fault, irrespective of which scenario applies. The car should have been returned to me in the same condition (or better) than when I dropped it off, which was that it had a maximum range of 238 miles and that the instrumentation would tell me what the range is. I don't think it is correct to compare the situation to a gas powered car since one can gas up anywhere anytime and it only takes 15 minutes. With an EV, you need to have an accurate view of your range since there are so few charging stations.

Thanks again
 
clustgarten said:
There are two scenarios, it seems to me. One is that the battery was damaged as a result of the recall and it really has only the range shown.

The other is that there has to be a "relearning" process.

...

My attitude was and still is that GM is at fault, irrespective of which scenario applies.
In a perfect world, perhaps. In this world, you're just going to have to accept that the battery management software update screws up the range estimate for the next few charge cycles. I learned from these forums that the symptoms are worse if you have the work done with a battery that's only partially charged, so I made sure to charge the battery to 100% before dropping the car off. When I got the car back my range estimate was only off by a minor amount.

If I recall correctly, the issue seems to be something along the lines that the software update resets the "distance traveled" since the last full charge to zero, but not the "energy used". So the algorithm believes that it's taken a bunch of energy to travel almost no distance, which then fouls up the range estimate.

You can rail about it as much as you want, but if this is the issue that's affecting you then the only solution is to just drive the car and recharge it as you go. In the meantime, watch the battery level rather than the range estimate.
 
clustgarten said:
The other is that there has to be a "relearning" process.

According to the technician at the dealer I spoke to, I would have to go through 10 drive cycles for the battery to complete its relearning process. Although I am a technologically oriented person, the concept that the car has to "relearn" makes no sense to me. I only had it a year when I brought it for a recall and it had only 3000 miles on it. What did it "learn" during that time?
Having to relearn doesn't sound out of the ordinary to me.

Batteries don't have any sort of output that says "this is my % state of charge". They have +, - and maybe temperature. You can definitely get the voltage, but that's doesn't by itself cleanly map to a % SoC.

Often, you hear about it being a good idea to drain a battery completely and recharge to full to re-calibrate a display/indicator (e.g. % SoC indicator/value). Example: https://forums.lenovo.com/t5/ThinkVantage-Technologies/How-to-perform-a-battery-gauge-reset/ta-p/679889.

A quick Google search turned up https://training.ti.com/sites/default/files/BatteryMonitoringBasics.ppt (OCV = Open Circuit Voltage) and https://batteryuniversity.com/learn/article/battery_calibration.

When Leafs have shady people resetting the vehicle without replacing the pack (reset is only supposed to be done when the pack is replaced), it can take weeks or months for the Leaf's capacity indicator to return to its actual capacity. Takes time for the car to re-learn the pack.

http://daveinolywa.blogspot.com/2014/11/buyers-beware-this-is-must-read.html
http://daveinolywa.blogspot.com/2014/12/update-saga-of-vin-222-resolved.html - that 9 capacity bar (out of 12) car showed up with 12 due to the reset but eventually within ~4 months became an 8 bar car. Battery was replaced via the 5 year/60K capacity warranty (have to be at 8 bars or less before expiration).
http://www.mynissanleaf.com/viewtopic.php?p=489739#p489739 - read posts by AntronX

Sorry, I'm not an EE, chemist nor battery engineer, so I'll have to defer to people w/more knowledge.
 
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