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Yeah.. I hope he is doing OK in this pandemic. I would dearly love to have him video the whole process of this recall on his Bolt, and then the final fix GM comes up with. He may be our best hope for really finding out what they have done to address this problem.
With all due respect to Prof. Kelly, whose knowledge and professionalism are clearly evident from every one of his videos, I doubt that battery chemistry and construction are his balliwick.
 

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With all due respect to Prof. Kelly, whose knowledge and professionalism are clearly evident from every one of his videos, I doubt that battery chemistry and construction are his balliwick.
I didn't suggest he analyze it. I said video/ document the procedure
 

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I didn't suggest he analyze it. I said video/ document the procedure
Sure, but if the procedure is something like "install new BMS software" or "replace battery pack" it's not really going to tell us all that much about exactly what GM did to solve the problem.
 

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I'm more interested in seeing what the Weber State Chevy Bolt EV's battery voltage spread looks like after he reassembled the battery correctly. If it looks more like the 2020 Bolt EV than a 2017 Bolt EV, that could indicate that the issue was with the assembly process.
 

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I'm more interested in seeing what the Weber State Chevy Bolt EV's battery voltage spread looks like after he reassembled the battery correctly. If it looks more like the 2020 Bolt EV than a 2017 Bolt EV, that could indicate that the issue was with the assembly process.
Hence a manufacturing defect and eligible for warranty repair / replacement? Hehe, referencing the 'Vette rim video here.
 

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Hence a manufacturing defect and eligible for warranty repair / replacement? Hehe, referencing the 'Vette rim video here.
Yeah, I didn't watch that video. By GM handling it the way they have, they've basically acknowledged that it was a manufacturing issue, and these batteries will be updated, repaired, or replaced, with or without warranty coverage. In my case, that last part is important.

The more I look at the discrepancies in voltages, the less I'm inclined to accept anything less than a 2020 replacement pack.
 

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Yeah, I didn't watch that video. By GM handling it the way they have, they've basically acknowledged that it was a manufacturing issue, and these batteries will be updated, repaired, or replaced, with or without warranty coverage. In my case, that last part is important.

The more I look at the discrepancies in voltages, the less I'm inclined to accept anything less than a 2020 replacement pack.
The TL;DR of the video was someone sharing how GM screwed over Corvette owners with broken rims by claiming that the rims were an inherent design flaw, and not a manufacturing defect, hence refusing to cover damages.

I completely agree with you on your thoughts regarding the current situation, though. I've been hoping for at least a new pack ever since the issue came to light (more of a gut-feel, please-do-right-by-us kind of thing), but as more evidence comes out, the case for this as the correct and ethical solution becomes stronger and stronger.

As you're aware, you in particular have a much larger platform than most of us on this forum because of your channel, and as such hope that you continue to advocate for us lowly peons who are vulnerable to getting screwed over by GM.
 

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The TL;DR of the video was someone sharing how GM screwed over Corvette owners with broken rims by claiming that the rims were an inherent design flaw, and not a manufacturing defect, hence refusing to cover damages.

I completely agree with you on your thoughts regarding the current situation, though. I've been hoping for at least a new pack ever since the issue came to light (more of a gut-feel, please-do-right-by-us kind of thing), but as more evidence comes out, the case for this as the correct and ethical solution becomes stronger and stronger.

As you're aware, you in particular have a much larger platform than most of us on this forum because of your channel, and as such hope that you continue to advocate for us lowly peons who are vulnerable to getting screwed over by GM.
Yes, I've already recorded another video where I broach the subject of voltage tracking in Torque Pro. I'll likely use that as a stepping off point for the discrepancies between packs subject to recall and packs not subject to recall. I'd really need to see more 2020 pack data, though. There's no reason for a >0.02 V discrepancy between cell groups, and that's already enough to trigger module replacement as far as Hyundai is concerned. There's also no reason that a chemistry update would result in such balanced cell voltages in the 2020 Chevrolet Bolt EV. That's the result of manufacturing, assembly, and a superior BMS (which, by the way, supports a more advanced charging curve).
 

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Yes, I've already recorded another video where I broach the subject of voltage tracking in Torque Pro. I'll likely use that as a stepping off point for the discrepancies between packs subject to recall and packs not subject to recall. I'd really need to see more 2020 pack data, though. There's no reason for a >0.02 V discrepancy between cell groups, and that's already enough to trigger module replacement as far as Hyundai is concerned. There's also no reason that a chemistry update would result in such balanced cell voltages in the 2020 Chevrolet Bolt EV. That's the result of manufacturing, assembly, and a superior BMS (which, by the way, supports a more advanced charging curve).
Cool beans. That other thread on cell voltages was definitely instructive. It shows a very reproducible phenomenon on the cell variations, with the same culprit cell clusters. Looking forward to seeing how this all unfolds.
 

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The more I look at the discrepancies in voltages, the less I'm inclined to accept anything less than a 2020 replacement pack.
I want you to get a new battery too, because I want the best for you, but selfishly I would also be happy if you didn't, because I'm very curious to see continued data on how these batteries perform as time and miles go by.

If the decision came down to me, I'd give you the new battery, but I wouldn't be entirely disappointed if you didn't. I would be entirely disappointed if you no longer shared your experience though.
 

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I want you to get a new battery too, because I want the best for you, but selfishly I would also be happy if you didn't, because I'm very curious to see continued data on how these batteries perform as time and miles go by.

If the decision came down to me, I'd give you the new battery, but I wouldn't be entirely disappointed if you didn't. I would be entirely disappointed if you no longer shared your experience though.
Yes, I thought about that as well. The continued life cycle of the battery is something I wanted to follow, which is why I wouldn't be upset if the solution was a replacement BMS and rebalancing of the cells.
 

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Yes, I've already recorded another video where I broach the subject of voltage tracking in Torque Pro. I'll likely use that as a stepping off point for the discrepancies between packs subject to recall and packs not subject to recall. I'd really need to see more 2020 pack data, though. There's no reason for a >0.02 V discrepancy between cell groups, and that's already enough to trigger module replacement as far as Hyundai is concerned. There's also no reason that a chemistry update would result in such balanced cell voltages in the 2020 Chevrolet Bolt EV. That's the result of manufacturing, assembly, and a superior BMS (which, by the way, supports a more advanced charging curve).
Not trying to be argumentative but I'm throwing in my 1 cent (2 cents is reserved for peoplel who know more than me). :)

My battery charger/balancer for RC car batteries has a setting for variance. It'll let you set it but it won't go below a certain value. You have to pick a spread you think you can maintain based on the accuracy of the measurements, what you expect the batteries can do, etc. Else the BMS/balancing will run too long, time out, and maybe stress the batteries unnecessarily. It's my guess that they felt like tightening up the variance is a double edged sword and going to (let's say) .01V would break more than it fixes. Why most of us find the same cells higher/lower is a mystery. Could even have to do with the board design, heat, and the ability to accurately measure voltage on certain sections of the board.

Also, I think the Kona and Niro use lithium polymer batteries which, at least in my experience with RC cars, are a lot more touchy than the non-polymer lithium ion batteries. It might be that .02V is fine for the particular cells they are using. I mean, we have a lot of 2017's with a lot of miles on them... and they exhibit the same cell variance as new and very little degradation.

Mike
 

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Not trying to be argumentative but I'm throwing in my 1 cent (2 cents is reserved for peoplel who know more than me). :)

My battery charger/balancer for RC car batteries has a setting for variance. It'll let you set it but it won't go below a certain value. You have to pick a spread you think you can maintain based on the accuracy of the measurements, what you expect the batteries can do, etc. Else the BMS/balancing will run too long, time out, and maybe stress the batteries unnecessarily. It's my guess that they felt like tightening up the variance is a double edged sword and going to (let's say) .01V would break more than it fixes. Why most of us find the same cells higher/lower is a mystery. Could even have to do with the board design, heat, and the ability to accurately measure voltage on certain sections of the board.

Also, I think the Kona and Niro use lithium polymer batteries which, at least in my experience with RC cars, are a lot more touchy than the non-polymer lithium ion batteries. It might be that .02V is fine for the particular cells they are using. I mean, we have a lot of 2017's with a lot of miles on them... and they exhibit the same cell variance as new and very little degradation.

Mike
My understanding is that the Hyundai Kona Electric uses the same NCM 622 chemistry as the Chevy Bolt EV. In fact, because they also bought the battery from LG as an off-the-shelf solution, it appears that the two batteries are very similar except for the specific design/format specifications set by GM and Hyundai.

Now you could be right about the allowable variance, but I'd expect that the variance would be tighter for an automotive grade BMS. The Orion BMS quoted at 0.25% accuracy with a ~1.5 mV resolution. Regardless, Hyundai has already started replacing any battery modules with >0.02 V variance, so I would expect GM to do something similar. Possibly rebalance them if they can, or simply replace them and rebalance the pack. Given the 2020 Bolt EV batteries that we've seen so far, it's certainly within GM's capability to balance the cells to a much lower variance.
 

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My understanding is that the Hyundai Kona Electric uses the same NCM 622 chemistry as the Chevy Bolt EV. In fact, because they also bought the battery from LG as an off-the-shelf solution, it appears that the two batteries are very similar except for the specific design/format specifications set by GM and Hyundai.
My understanding was that you can use the same (622) chemistry whether it's a standard li-ion battery or a li-po battery. Only difference is whether or not it uses a polymer electrolyte which some claim is even safer than the non-polymer but I haven't had good luck on the charging front personally with li-pos on RC vehicles and craft. Could be the charger, me, or lack of understanding about the charging requirements though.

Mike
 

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My understanding was that you can use the same (622) chemistry whether it's a standard li-ion battery or a li-po battery. Only difference is whether or not it uses a polymer electrolyte which some claim is even safer than the non-polymer but I haven't had good luck on the charging front personally with li-pos on RC vehicles and craft. Could be the charger, me, or lack of understanding about the charging requirements though.

Mike
Yes, you can, but my understanding is that GM and Hyundai are using the same LG NMC 622 battery cells. According to the spec sheets in this article, GM is also using a polymer electrolyte in the Bolt EV's battery cells: Jaguar and Chevy have LG in common
 

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Yes, you can, but my understanding is that GM and Hyundai are using the same LG NMC 622 battery cells. According to the spec sheets in this article, GM is also using a polymer electrolyte in the Bolt EV's battery cells: Jaguar and Chevy have LG in common
Yeah, I've seen reference to the Bolt batteries being "lithium ion polymer" but other references that specify "li-ion" whereas the Kona/Niro are almost always listed as "li-po". Probably better for me to just keep my head in the sand at times because I really can't be confident whether the Kona/Niro have the same cells as the Bolt or not. Too much conflicting information for me to decipher out there.

Mike
 

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Yeah, I've seen reference to the Bolt batteries being "lithium ion polymer" but other references that specify "li-ion" whereas the Kona/Niro are almost always listed as "li-po". Probably better for me to just keep my head in the sand at times because I really can't be confident whether the Kona/Niro have the same cells as the Bolt or not. Too much conflicting information for me to decipher out there.

Mike
I'm pretty sure that the Niro EV has different cells than the Bolt EV and Kona Electric, though they might be nearly identical in chemistry. As I understand it, KIA worked with SK Innovation for their cells. I think part of the drama with the Korean battery manufacturers right now is due to that. LG believes SKI stole proprietary formulas, information, processes, tech, etc. (and as a result, stole customers).
 
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