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Discussion Starter · #1 · (Edited)
Even tho I work in the tech industry, I don't do much with Facebook, so not sure how to link to the post. ;-)
It was in this forum: (Thanx for the non-mangled link!)


(Note: The below was not posted by me.... Just passing this along..)
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Hi friendly neighborhood volt/bolt tech here! First let me say that I am not an official GM spokesperson and I am expressing my interpretations of the information I have gathered. It is absolutely possible not every detail is exactly correct and things certainly could change as the process progresses and more is learned.
We received both of the final recall procedures and updated info at the dealer today and I thought I would update you all on what I have been able to gather as a master gm technician of 15 years, gold certified high voltage hybrid/ev specialist, and ev enthusiast. We'll start with the potential causes of the fires as I have come to understand it.
GM originally identified a manufacturing defect present in some battery cells (I'm not sure which of the 2 was identified first), and proceeded to develop and deploy a software "final fix" that they believed would identify a defective cell before it propagated into a fire by monitoring for excessive cell voltage variation among other things. If this was the only defect present this software likely would have been successful in averting any further fires. After this software proved unsuccessful the investigation intensified and after inspecting many batteries and LG's manufacturing processes, a second defect was uncovered. The two possible defects identified are a torn anode tab and a folded seperator. Neither one of these defects are a real big deal independently but in the very rare case that they both occur within the same cell, the combination of the two can create a point of failure. That point of failure still needs to be aggrivated though, and this is where different operating conditions and vehicle uses come in.
Current draw, charging rates, ambient temperatures, battery temperatures, fully charging/deep discharging often, etc all produce different heating and cooling patterns for each individual bolt. Only some sets of specific use conditions will cause the cell's expansion and contraction rates to be large enough to allow a short in the cells that contain both defects.
Now for the final... final fix.
Gm believes they have identified certain build date time frames that the defects seem to be clustered, so those vehicles will have initial priority. Customer owned vehicles currently awaiting repair after failing either the on-board or dealer battery module diagnostics will also be prioritized. I suspect vehicles with the specific identified use patterns that are most likely to produce the largest cell expansion and contraction rates will likely also be prioritized as well, but haven't specifically confirmed that. Every bolt is currently under one of two recalls, N212345940 (2020-2022) or N212343880 (2017-2019). Once vehicles are eligible for repair they will be migrated from N212343880 to N212343881 and from N212345940 to N212345941. These two new recall numbers are what we got copies of today at the dealer. They both clearly state the correction as "Dealers will replace the lithium-ion battery pack in the vehicle." I have read all 50 pages of each recall and there are no inspections or section/module/row replacements, or software only repairs. There are dozens of required tools and pieces of equipment for this recall (including a forklift to load and unload multiple batteries), and the tools that would be needed specifically to replace modules/sections are not required for this recall. As of this writing all vehicles will be getting a whole, brand new, complete, fully assembled battery pack. Remember though this is a constantly evolving situation and more is being learned every day. If they discover a reliable way to identify the defective cells after inspecting tens of thousands of returned batteries, it's not impossible they would modify the recall to replace only defective modules. I don't personally think that is very likely but I've learned over the years nothing is impossible. We have already ordered our first three packs and have been told to expect them within 2 weeks. The new batteries will all include an extended 8-year/100,000-mile limited battery warranty.
GM has also said that within 60 days all vehicles will also get a new advanced diagnostic software package that will increase the available battery charging parameters over existing guidence while also performing new onboard diagnostics to identify and prioritize replacement for vehicles with bad cells.
Quote from GM:
"The diagnostic software will be designed to detect specific abnormalities that might indicate a damaged battery in Bolt EVs and EUVs by: monitoring the battery performance; alerting customers of any anomalies; and prioritizing damaged battery modules for replacement. It is GM’s intent that further diagnostic software will allow customers to return to a 100 percent state of charge once all diagnostic processes are complete."
GM will send letters to customers when their vehicle is migrated from the old recall to the new one and is eligible for battery replacement. The recall will take the better part of a day to complete and the vehicle must have a minimum of 24 hours between the last high voltage battery charge (plug in charging) and the beginning of the high voltage battery removal so don't plug it in the night before you take it or it'll have to sit overnight before it's worked on.
So there it is folks. That's all I currently know and hopefully it will put a few minds at ease. I'll try to answer any and all questions that I can as quickly as possible but I also work and have a 2 year old so you'll have to bear with me if it's delayed.
 

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Code:
https://www.facebook.com/groups/chevyboltevowners/posts/2966391527005787/
is a friendlier, non-mangled link.
 

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"The diagnostic software will be designed to detect specific abnormalities that might indicate a damaged battery in Bolt EVs and EUVs by: monitoring the battery performance; alerting customers of any anomalies; and prioritizing damaged battery modules for replacement."

Did anyone else catch the keyword in the above sentence from GM? "Might" indicate a damaged battery? So then it might not? What does that mean? That even after this newest round of recall repairs is complete, they're still not completely confident about the battery? And there still could be a problem that might not be detected?

As someone who is on the fence with confidence in the Bolt now, that just took a big negative hit to it. With how delicate this situation has been, I'm surprised GM would put out a statement like that.
 

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What I take from this.

1. The software update is intended to identify vehicles that are in a use case and batteries with an enhanced risk of fire. They will be pushed to the front of the line for full battery replacement.
2. All cars will be getting a full battery replacement regardless at some point.
 

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"The diagnostic software will be designed to detect specific abnormalities that might indicate a damaged battery in Bolt EVs and EUVs by: monitoring the battery performance; alerting customers of any anomalies; and prioritizing damaged battery modules for replacement."

Did anyone else catch the keyword in the above sentence from GM? "Might" indicate a damaged battery? So then it might not? What does that mean? That even after this newest round of recall repairs is complete, they're still not completely confident about the battery? And there still could be a problem that might not be detected?

As someone who is on the fence with confidence in the Bolt now, that just took a big negative hit to it. With how delicate this situation has been, I'm surprised GM would put out a statement like that.
The final and most dependable remedy will be the full battery replacement. Even that wlll not guarantee 100% battery safety. This will never happen... Anything that uses power wether from electricity or combustible liquids will always have a risk of burning up. If you want 100% fire proof, better ride your bike or walk ;)

In the meantime, they are trying to help mitigate everybody's inconveniences...
 

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will increase the available battery charging parameters over existing guidence while also performing new onboard diagnostics
I don't know any techs that use sentences like this. They might say "It will let you charge to 100% again". Maybe this is a tech, regurgitating bits of a GM bulletin, with typos and commentary.(*)

I saw nothing new there, other than the bit about doing whole-pack replacements.

(*) Unless it's a tech who would tell their teenager "Son, last year we said we wanted you home by 9pm. Now that you're 16, we've decided that you may extend recreational activities beyond previous guidance."
 

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Good find desiv.
Thanks.

Had no doubt btw about source.

Sort of have a one track mind focused on the day the pack is replaced and figure anything before then won't matter once that happens.

Tracking the Bolt saga is an interesting deep dive adventure into GM corporate history with a vested-interest connection that I appreciate every day.

Not many Bolts around here. Lots of interest in what the heck is getting away from lights so quick and ICE trucks jacked up with big tires wasting gas trying to catch up.

If the post is accurate, glad to keep mine and keep telling friends to find a low miles 2017, or any.
 

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He stated all the facts. I would have liked him to be more specific to his knowledge and experience actually replacing a full battery and his thoughts that it can be complete in about 5 hours. I sounded more like a PR release than a Tech letting everyone know what to expect.
 

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Russian Troll? LOL
 
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I don't know any techs that use sentences like this. They might say "It will let you charge to 100% again". Maybe this is a tech, regurgitating bits of a GM bulletin, with typos and commentary.(*)

I saw nothing new there, other than the bit about doing whole-pack replacements.

(*) Unless it's a tech who would tell their teenager "Son, last year we said we wanted you home by 9pm. Now that you're 16, we've decided that you may extend recreational activities beyond previous guidance."
I agree! I could’ve put out this statement. It reads like a plagiarized paper in high school.

What do Techs know anyway? They’re so far down the food chain. They just receive a detailed procedure and are told to execute it. They may end up criticizing it, and maybe even suggesting improvements and tweaks, but that’s about it.
 

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Further quotes from FB by the tech:

"As of this moment all bolts will get a new battery since there is currently no reliable way to inspect for the defects."

"I don't yet know alot of specific technical details about the software yet because they haven't released that recall info to us yet, but now that they know exactly what the defects are and the specific vehicle conditions that are most likely to allow enough cell expansion/contraction to allow a short in the double defect cells they can theoretically much more accurately predict if a vehicle is begenning to show the signs. The way I interpreted it is that the software will perform new onboard diagnostics and monitor vehicle operating conditions for those signs. If it sees signs of a problem it will be prioritized for battery replacement and if it does not see signs of a problem some charging and/or parking restrictions will be lifted. I'll probably have more info on this and be more confident in my answers once the software recall procedures are released. "
 

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I wonder if all model years will also get the same battery management software too, i.e. 2017 getting rid of hilltop reserve in lieu of what the later years have.


Sent from my iPad using Tapatalk
 

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Did anyone else catch the keyword in the above sentence from GM? "Might" indicate a damaged battery? So then it might not? What does that mean? That even after this newest round of recall repairs is complete, they're still not completely confident about the battery? And there still could be a problem that might not be detected?
The "might" is in reference to identifying problems with the defective batteries prior to them going up in smoke. They most likely used the term "might" because while they have found some sort of anomaly that can be created within the battery prior to an actual fire, they cannot tell us that it will catch every bad battery. In short, not every bad battery will have the same marker that this software update looks for.
Separately, GM has indicated that they are building "defect free" batteries. And while that cannot be true, because defects happen to some degree in any manufacturing process, they must be very confident that they solved the problem that resulted in this fires in the first place.

What do Techs know anyway?
EV techs have to go through a ton of training before they can work on these batteries. Many dealers have received visits from their GM reps recently to go over everything about this recall. So, right now, these techs that you think so lowly of are probably the best source of INFO we can ask for.
 

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...
In the meantime, they are trying to help mitigate everybody's inconveniences...
Are they though? I mean, the inconveniences started with the first recall back in Nov. 2020, that's getting really close to a full year now and gm hasn't done anything to mitigate it from my perspective. In fact, they have added to the inconveniences over that time.
 

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Are they though? I mean, the inconveniences started with the first recall back in Nov. 2020, that's getting really close to a full year now and gm hasn't done anything to mitigate it from my perspective. In fact, they have added to the inconveniences over that time.
If GM does not add the extra inconveniences, then one could argue that GM wasn't showing any concern about the peoples' safety. If GM does add them, then owners are being put out. GM chose to do it anyway, despite this. Now, they have announced a plan to help offset some of that inconvenience WITHOUT placing people, and homes, and cars at extra risk. Nobody is telling you that GM handled this all perfectly from the start (clearly they did not) but in the here and now, there is no question that they are indeed trying to mitigate inconvenience.

They cannot fix their past mistakes. They can, however, try not to repeat them.
 
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