Monday, August 23, 2021

GM recalls Chevy Bolts due to battery fires

Via the New York Times: 

General Motors said on Friday that it was expanding its recall of Chevrolet Bolt electric cars that have been found to be at risk of overheating and catching fire as a result of manufacturing defects.

The company said it was recalling Bolts from the 2020 through 2022 model years and a few 2019 Bolts that were not covered under a previous recall. The move means all 141,000 Bolts that G.M. has produced — going back to the 2017 model — are under recall.

...G.M. said the move announced on Friday would cost the company $1 billion on top of the $800 million it had allocated for previous Bolt recalls. It also said it would seek reimbursement from its battery supplier, LG Chem.

...G.M. and LG Chem have linked the fires to two manufacturing defects that occur on rare occasions. The companies have found that a short-circuit can occur if an anode tab is torn in manufacturing and if a separator between battery cells becomes folded. Under the recall, G.M. plans to replace the defective battery modules.

The videos of the fires are pretty dramatic, as one would expect. I imagine this is the sort of problem you expect at the beginning of a new technology - will be interesting to see how engineers and scientists solve this problem. 

5 comments:

  1. I'll be curious to see when Tesla will issue a recall for the same issue.

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  2. "I imagine this is the sort of problem you expect at the beginning of a new technology"

    No, this is a problem inherent in the electromobile. All that lithium metal stored in closed proximity of oxidizer (higher oxides of manganese or nickel, cobalt).
    If you burn 14 kilos of diesel or gas with 48 kilos of oxygen from air, you produce 62 kilos of exhausts, it goes out of the tailpipe. A rechargeable battery with the same energy capacity will weight at least half a ton. With rechargeable battery, you move all that fuel and oxidizer and spent fuel weight around, not mentioning electrolyte and electrode material. The battery weights the same when charged and discharged. The energy density of lithium batteries is about 30-35 times lower than of gasoline. You cannot improve the battery energy density much further, and the safety (i.e. due to shorting resulting from a collision) is always going to be an issue. And electromobiles are always going to be far more expensive, a toy for the rich. The practical way forward is with hybrids.

    ReplyDelete
    Replies
    1. Milkshake, while I agree on most points above, the practical way forward is not with gas ICE/battery hybrids. One issue that is becoming obvious and problematic in hybrids is the engine not being used or used in a short-cycle, so it's often cutting on and off, which increases wear and decreases the life of the ICE. In my opinion, the only way forward with ICE technology is hydrogen as a fuel source. However, what rules everything is money, and that will require quite a significant infrastructure investment (moreso than what we have with electric charging stations) and there is not as much consumer willingness to spend the money on currently-offered hydrogen-powered vehicles on the market.

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    2. Sorry dude, hydrogen fuel is a rabid nonsense, as any synthetic chemist can tell you (low energy density per volume and low compressibility prevents effective storage. Hydrogen embrittles metals, has extremely low viscosity = easy leaks and it burns with invisible flame). It has to be manufactured from natural gas. All those drawbacks can be avoided just by using natural gas directly in a combustion engine

      Also your point about hybrids is nonsense.

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    3. Milkshake, you are right about CNG as an alt fuel but wrong about hybrids and hydrogen as a fuel source. These are the best alt fuel paths forward for the ICE. And my tidbit about hybrids is 100% factual. Hybrids are terrible and should not be the path forward and thankfully appear to be heavily disfavored.

      The ICE is dead unless efficient hydrogen or CNG fueled ICEs can be developed and actually sold to consumers. Electric is the future though; the writing is on the wall.

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looks like Blogger doesn't work with anonymous comments from Chrome browsers at the moment - works in Microsoft Edge, or from Chrome with a Blogger account - sorry! CJ 3/21/20