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That hypothetical does not apply to the situation at hand.
It could, based on my hypothetical example I gave in that post.
But, if (and this is purely hypothetical) LG says, we can guarantee that we have fixed one of the two issues. But the other one would require a design change, so we can't get to that one for this series of batteries. That said, with the one fixed, we have addressed the fire issues..
If LG said that and for the sake of this hypothetical, it was true, I could see GM going with that...
If there is a defect that doesn't affect performance and isn't a fire risk, is that a problem?
Not saying it does, hence the word hypothetical, but it could...
 

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GM is not the only auto manufacturer to outsource it's batteries. In fact Tesla is more of an outlier handling this internally. It's great that so far it seems to have worked well for Tesla, but GM is not grossly negligent by deciding to buy batteries rather than produce them.

We're all frustrated by the situation, but we need to maintain perspective.
And LG had proven itself as a supplier of reliable and safe battery packs over the 9 year run of Volts. Perhaps GM could have done a better job of overseeing LG's production, and they certainly will going forward.
 

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Counting cards works differently. The makeup of the deck changes as each card is revealed. In contrast, each Bolt is independent from all others. As fires happen, our understanding of the chances may change, but the actual chance of each car to catch fire does not change.
Wouldn't the odds go up? One more fire (lets say 21 now instead of 20), and 139,999 bolts left out of 140,000 yesterday?

21/139,999 is greater than 20/140,000.

But maybe this is like the Monty Hall puzzle and I'm a dodo!
 

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GM is not the only auto manufacturer to outsource it's batteries.
Your are right, OLD car makers have forgotten to on how to make cars. They are now marketing departments with
the actual car guys being thought of as a painful necessity. Why is GM scrambling? This issue has been around for more than a year. Suddenly they are trying to figure out how the batteries they bought work and why they fail. What's changed?
 

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Wouldn't the odds go up? One more fire (lets say 21 now instead of 20), and 139,999 bolts left out of 140,000 yesterday?

21/139,999 is greater than 20/140,000.

But maybe this is like the Monty Hall puzzle and I'm a dodo!
The observed incidence of fires does go up from 20/140000 to 21/139999 like you said. But I’m assuming that there is some underlying (and unknown) risk/defect rate/chance that determines how likely a Bolt is to catch fire. This underlying fact may vary by model year, battery origin, usage history, phase of the moon, whatever. We can use information about the fires that happen to try and better learn what the real chance of fire is. If we keep seeing more fires, it’s reasonable to keep adjusting our understanding of the risk upwards.

But when we get news of a fire, it doesn’t change the (real, unknown) chance that my Bolt, or your Bolt, or any particular Bolt will burn.
 

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The observed incidence of fires does go up from 20/140000 to 21/139999 like you said.
If there were 140K Bolts before, and one is totaled in a fire, the total number of Bolts is still 140k, though one less is on the roads.

If you are trying to figure out odds, fires/total number produced is more accurate than fires/on the road. Yes, odds go up with each additional fire occurrence, but the total fleet numbers remain constant (until GM re-starts production).
 

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Your are right, OLD car makers have forgotten to on how to make cars. They are now marketing departments with
the actual car guys being thought of as a painful necessity. Why is GM scrambling? This issue has been around for more than a year. Suddenly they are trying to figure out how the batteries they bought work and why they fail. What's changed?
I think it's more than that. Tesla has the advantage of being a new company focused solely on electric cars. Battery production in house makes a lot of sense for that business model. Other manufacturers, GM included, have more varied products to maintain and they can't simply cut off funding for ICE cars to focus on electrics. So outsourcing parts of the car that don't feel they can invest in producing makes sense. GM is still making great cars, so I think their engineering is sound.

Why are they scrambling? My guess is that since they didn't engineer the batteries they're having to get very familiar with LG chems engineering process to try and help figure out what is going on. This is very low defect rate issue that burns up the evidence when it occurs. So not exactly the easiest problem to solve.
 

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Yes, odds go up with each additional fire occurrence
The "observed" odds goes up but the unknown, underlying odds remain the same. As more fires are observed, those odds get closer to the underlying odds. So if you assume that there will be at least one additional fire in the future, the real, underlying odds are always greater than the observed odds.
 

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If there were 140K Bolts before, and one is totaled in a fire, the total number of Bolts is still 140k, though one less is on the roads.
Agreed!
Another tricky thing about the actual odds is that we are likely never going to know them.
In order to know them, we'd have to know how many fires would have happened.
But as LG is likely to fix them and/or GM is likely to buy back Bolts, we won't ever know how many there would have been to be able to figure out the odds with any statistical certainty.

All we can do is project based on what we know. And even that is tricky.
We haven't been able to see any particular rate based on age or anything...
So we can't say "there are x fires per model year per year" with any real accuracy....

I think there have been something like 4 or 5 fires in 2017 models, so can we guess that the average risk of fires is 1 per year for what... What is the expected lifespan of a Bolt and it's battery? 15 years? So the odds would be 15 out of 25,000 or so 2017 model years? So 0.0006???

Although, if age/use pattern is a factor, that changes this... Which we might expect...
But, we haven't seen that yet (we haven't seen more fires for the 2017 models as they age, although there was a 2017 fire somewhat recently)... If anything, we have seen the opposite, but with a sample size of 4 or 5 fires, it is really tricky...

As much as I like poking at various scenarios, I think the best I'll be able to get to is that the risk is low.
It is also higher for the 2019 model year.

I honestly think the X out of XX,XXX isn't ever going to give us anything reliable...
But it is fun... ;-)

Now, what would change that would be if LG/GM says "Hey we found out the problem and we know that X number of cells of our whole run had defect #1 and x number of cells had defect #2.
Then we have a known quantity to predict odds...
But even then, we'd need to know things like, what are the odds of a fire happening with both defects? Is it 100%? Or would even that depend on the severity of the defects?
 

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...As much as I like poking at various scenarios, I think the best I'll be able to get to is that the risk is low.
It is also higher for the 2019 model year...
Not just higher for the 2019 model year with batteries made in Korea, but very much higher. That particular group represents roughly 50-60% of all fires but roughly 10% of all Bolts. (We still don't know if this one had a battery made in Korea.)
 

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Right - while they won't crawl under an active EV fire to hook something to the frame and they won't fish around in the trunk for a tow eye to install they might be able to hook onto the tow eye if it's already installed. It's cheap and easy extra insurance for your house. You will get questions on WTF is that thing for?
A few weeks ago I managed to get my bolt hung up on a curb (I should not be permitted to drive at night, in the rain). Called AAA. The tow truck guy showed up and hooked a strap through one of the rear wheels, and used that to pull the car off the curb. Wow; I would not have thought that was a thing one should do. But I'm pretty sure guys who do this sort of thing for a living know what they are doing.

I'm currently parking inside my garage. I called State Farm to check whether, if the car catches fire and my house burns, it's covered by insurance, since I'm ignoring the recall "advice." I was told yes (huge relief!)

I currently have a broken passenger window; three weeks ago someone busted it while I was hiking. The glass company finally (two days ago) got approval for the claim (I've always had State Farm, but am now thinking of switching). It will take 7-10 days for the glass to get here, and only after that will the glass company schedule me. So, it looks like another two weeks. Well over a month to get a broken window in a car replaced? This is nuts. Of course, I'm sure it will be at least a year before/if my battery gets replaced.
 

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"let’s all drive to Detroit and park our Bolts at GM HQ."

Then the odds would be 140K Bolts stolen in Detroit. A fire broke out at a chop shop behind a city council members home. Many parts now show up on (online auction site)
 

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"let’s all drive to Detroit and park our Bolts at GM HQ."

Then the odds would be 140K Bolts stolen in Detroit. A fire broke out at a chop shop behind a city council members home. Many parts now show up on (online auction site)
Low blow! But funny.
 

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Something I just read really irked me
According to Reuters, the GM CFO used these terms to explain why GM is still not replacing the defective battery packs, which made the Bolt EV catch fire multiple times. GM does not expect to do that before November,
Starting November at the earliest?
 

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GM is still not replacing the defective battery packs, which made the Bolt EV catch fire multiple times. GM does not expect to do that before November,
I don't think they have verifiable good packs to replace them with, and November isn't that far away...
Even if LG popped up tomorrow and said, "Hey! These are safe!" it's conceivable that GM wants some time to validate that and prepare...
 

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I don't think they have verifiable good packs to replace them with, and November isn't that far away...
Even if LG popped up tomorrow and said, "Hey! These are safe!" it's conceivable that GM wants some time to validate that and prepare...
Assuming LG now has verified good battery cells, the cells still have to be packaged into the modules, wired together into a string, and assembled with the rest of the BMS electronics into a battery pack ready to ship to GM. This will require many weeks as the batteries have to be shipped by ocean freight from Korea or ground trucking in USA.
 

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Based on the address mentioned in the posting on the fire department's web site, the location is about a mile from the nearest fire station in a rural area, so it presumably did not take long for the fire department to get there.
 

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Not just higher for the 2019 model year with batteries made in Korea, but very much higher. That particular group represents roughly 50-60% of all fires but roughly 10% of all Bolts. (We still don't know if this one had a battery made in Korea.)
I have been catching up on these threads on an idle rainy day -- was away doing other stuff much of the summer so I missed a lot of the hoopla and have come back to an altered discussion group! This is one of the most useful comments (imho) so far. If 50-60% of fails are happening in 10% of the total Bolt population than that is indeed significant.

I agree that the potential severity of an event needs to be factored into our perception of the risk. But the odds so far still seem to me "not that bad." 150,000 Bolts and what, 15 fires so far? 1 in 10,000? Where I live, the odds on a colonoscopy resulting in a perforated bowel and followup repair surgery is about 1.5 in 2,000, or 7.5 in 10,000. Yet very few people are up in arms about this, or refusing to get colonoscopies in light of these odds. Maybe that's only because those stats are not widely publicised, who knows. But... I think keeping my Bolt is less scary than a colonoscopy :) Which some folks get every couple of years.

An argumentative reader might say that the colonoscopy, however risky, is undertaken in the hope of preventing the far, far greater risk of cancer. I don't think that really dynamites my analogy though, as I kinda see my EV as being undertaken as some kind of feeble gesture warding off the far, far greater risk of climate catastrophe (how effective this gesture is, we could debate till the cows come home, but it is a motivation for me).

Risk is funny that way. Actuarial risk and perceived risk bear only a distant relationship to each other. That said, I'm still kinda glad my Bolt is a 2018 :) And I am quite attached to it and absolutely not keen on a forced buyback... so hoping GM makes good and starts rolling out replacement batt packs soonish.

My complacency is also, I admit, coloured by my use case. I hardly ever drive long distances and find it easy to keep the car charged in the comfort zone between 40 and 80 pct. So I can understand that folks who push their Bolts near the range limit on a regular basis would be far more nervous than I am, and much angrier with Chevy/GM.

It's interesting that (afaik) so far all the burning Bolts have been sitting still, charging? none has burned up on the road, while draining the battery?
 
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