About Those Flaming Sparky Cars… GM Recalls ALL EV Bolts

It is a simple matter of electrochemical reality. Lithium Ion Batteries grow “dendrites”; little spikes of lithium, that eventually short out the cell. Then some of them burst into flame. It’s what they do. This can be slowed down by never discharging fully, leaving 20% or so of the battery unusable, or by not charging when it is too cold, or hot, or charging it very very slowly since fast charging promotes this too.

But what you can’t do is have it never ever happen. (Unless you change to a less power dense battery chemistry and lose a lot of range).

The end result is that, after enough years, or with some (sometimes minor) physical damage, your car bursts into flames.

General Motors has now figured this out:


NBC News
GM’s $2 billion Chevy Bolt fire recall casts shadow over electric vehicle market

Paul A. Eisenstein
Mon, August 23, 2021, 1:10 PM·3 min read

General Motors has expanded the recall of its Chevrolet Bolt electric car because of concerns about potential battery fires, adding 73,000 more vehicles, for a total of about 142,000 cars — every single one that Chevy has sold so far.

The combined cost of the recall will reach nearly $2 billion as the auto industry plans to roll out dozens of new electric models over the next 24 months to meet President Joe Biden’s goal that electric vehicles reach 50 percent of total U.S. sales by 2030.

GM’s EV lineup includes the launch of its electric Hummer pickup and an all-electric Cadillac Lyriq, which will use a different battery technology from the Bolt’s. The problem appears to involve manufacturing defects that can cause the batteries to short-circuit, even when parked.

No, “the problem” is why everything from laptops to cell phones (even Apple) to powered skate boards to Vape Pens and more have burst into flames from time to time. The best power density Lithium Ion cells like to grow dendrites of lithium if you charge and discharge them a lot, deeply, too fast, or at temperatures they do not like well.

It’s not the only manufacturer that has had to deal with EV fire problems. Hyundai has recalled about 90,000 of its Kona EV models because of what it said this year was the “increase[d] risk of a fire while parked, charging and/or driving.”

The problem with the Kona appears to have been the same as what ails GM’s Bolt models: manufacturing defects involving batteries supplied by LG Chem, one of the largest manufacturers of lithium-ion technology. The South Korean supplier’s shares took a sharp hit Monday in the wake of the Chevy announcement.

Other manufacturers, including the EV giant Tesla, have found themselves in the news because of battery fires. In December, a home in suburban San Diego was destroyed when a Tesla Model S caught fire as it was charging in the garage. Investigators blamed a faulty thermal management system designed to keep the battery pack cool.

Still, the coverage of EV fires may be overblown, said Sam Abuelsamid, lead auto analyst for Guidehouse Insights. Seven Chevy Bolts have caught fire, or about 0.006 percent of those on the road. By comparison, the National Fire Protection Association said 212,000 gas and diesel vehicles caught fire in 2018, or about 0.07 percent of those on U.S. roads.

“Yes, we’ve seen some battery fires, but the numbers are small, and they need to be put into perspective,” Abuelsamid said.

The longer a battery stays in service, the greater this risk becomes. It is proportional to charge / discharge cycles and depth of discharge. It is no surprise that the largely new batteries in the current fleet have a low percentage of burnup. But just give it time… Dendrites grow slowly over years if you have very good battery management (keep batteries in a narrow temperature range, never discharge below about 20%, never over charge, don’t charge really fast, etc. You know, all the things most folks don’t do…)

What we ought to be hearing about is the number of cycles to burnup and the number of years to burnup. Knowing WHEN to replace the battery before that point is what matters.

A very well designed battery will last longer than the rest of the car before it reaches that point. OTOH, I’m driving a 42 year old car (fine Diesel Mercedes) not a “5 years and rusted out” thing like they have Back East… so no EV for folks who like old, classic, or well used cars… In my opinion, of course.

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
This entry was posted in Economics - Trading - and Money, Emergency Preparation and Risks, Energy, News Related, Tech Bits. Bookmark the permalink.

20 Responses to About Those Flaming Sparky Cars… GM Recalls ALL EV Bolts

  1. Skid Marx says:

    When will Government Motors make the unicorn flatulence powered Zil Trabant?

  2. philjourdan says:

    I wonder how many of those “142k” Bolts were sold to governments? I have seen exactly 2 on the road.

  3. Ossqss says:

    I wonder if Toyota is doing something a little different. They provide a 10yr 150k warranty on their batteries for hybrid’s and EV’s.


  4. H.R. says:

    Hey! That Toyota Marai at the bottom of the link is one sharp looking car, Ossqss. It said ‘fuel cell’, but I’m not clear on whether that will be it or what for powering the vehicle.

    If a hybrid suits your needs, why would anyone buy any other make besides Toyota? They have a track record to back up their decision to run the warranty out further, and the warranty is transferrable. Used car buyers can rest easy.

  5. Ossqss says:

    Crap, I must have messed up the link. It doesn’t work for me. 404

    <b{<Reply: Link worked fine for me. Not messed up at all. -E.M.S.]

  6. David A says:

    Ossqss, I have a Rav 4 prime. They always have at about 20 percent of their battery remaining. They charge slow, about 4 hours max, 12 hours on a 15 amp 110. With scheduled charging they complete charge minutes before you leave.

    Seven Chevy Bolts have caught fire, or about 0.006 percent of those on the road.

    So we recall cars, but not vaccines?

  7. E.M.Smith says:


    Hybrids are different animals from rechargeable EVs. They must take surges of charge when you hit the brakes, into a smaller battery pack, then give back more power per pound than a dedicated EV. For this reason, they often use a different battery chemistry. IIRC the early ones were NiMh or NiCad. Nickle Metal Hydride is a really good fast charge / discharge battery, IMHO, and gets away from Cadmium that is truly a horror show toxin (your bones dissolve…)

    These are all known to have very extended lifetimes if well made.

    I’d be thrilled to have a small plug in hybrid DIESEL car. Volvo had a prototype wagon in about 1985 or so, but it never made it to production. There is just nothing wrong with that kind of package. IIRC it got about 60-70 MPG on the standard EPA test of the era. (Big gain is that there is an extended “stuck at idle” segment where the EVs and Hybrids are using NO energy at all… simulates stop lights and traffic jams).

    Oh Well. They didn’t ask me… nobody ever asks me… I’d have bought one… or two…

  8. Ossqss says:

    @David A, I been peekin at the Rav4 for a couple years. I really like the new models and the Off Road TRD version in particular, but also the XSE caught my eye with its 41mpg in city. I am just waiting for the prices to come down a bit and will probably do an AWD hybrid, as a plug in would not work for me.

  9. I’d rather have a rattlesnake in the garage than a car with Cadmium.
    See “the ouch-ouch” pages on the web.

  10. E.M.Smith says:


    There are some “plug in hybrids”, and that’s what I’d like to have. You can go something like 25 to 50 miles on the batteries alone before the engine kicks in. Then charge up when back at home. That would cover about 90% of my number of trips and about 3/4 of my “non-marathon” miles.

    IF I could “top up” at the other end of my two typical medium range trips (work , mechanic) then it would cover almost all of my “around town & local” driving. Yet I’d still be able to run to L.A. / Disneyland or make a Florida & Back run without stopping for a few hours out of every few…

    @John H:

    Cadmium is about as horrible a toxin as you can get. NiMH batteries also have much larger capacity (about double IIRC) so the NiCads are mostly history now. But yeah, no way you want to be near a NiCad in a fire… OTOH, they don’t burn well and are metals encased in steel, so don’t really have much of a leak / vaporize risk outside of “Car is a bonfire”; in which case the Cadmium is the least of your worries…

    (Cadmium substitutes for Zinc in enzymes, and since Zinc is critical to something in the hundreds of enzymes, you end up with hundreds of enzymes, and enzyme systems, that don’t work right or are entirely broken. And not much that can be done to fix it.)

  11. Terry Jackson says:

    Once had a house near Cleveland built about 1910. The garage was a 2-car, but…. Solid masonry walls and a flat cement roof. It was offset from the house about 6′, but connected via an entry room with doors to both the house and garage. Maybe they were concerned about sparky cars.

  12. David A says:

    They are all good cars. To bad the plug in won’t work for you. Advertised at 43 miles for the pure EV portion of the 18 KW battery. But I am consistently getting 53 pure EV before the gas motor kicks in when it then functions as a regular hybrid. So at 3.4 miles per kwh, I am very pleased. And it is a fun 5.6 zero to 60 with gas and EV both. The instant punch of the EV is different.

    Ya, it’s expensive, but with the inane $7500 kick back, plus a $1000 from California, plus another 1,500 from California, the cost difference is not to extreme. If you have a place to plug it in it’s a great car, so far. Dealer of course tried to sale me the warranty, and I wanted one, it supposedly very reliable, but a complicated machine. They would not budge below 1900 for Toyota platinum at 6 years 100 k miles. I passed, found a dealership back East, and got the 8 year 125 k mile for $1,500.

    Normally I never buy a new car, but the rebates plus the solar giving me about 600 miles of almost free driving each month, plus the 38 mpg on any hybrid miles almost pays for itself, verses the car I had. Add in the difference in residual value and my break even is about 7 years. ( assuming no major break downs with my other car had I kept it. )

  13. David A says:

    Since the prime stepped up to 18.1 KWH battery it us lithium ion. Yet it never falls below the hybrid maintenance range and the charge is slow. Also Toyota may have the full charge limited below the actual capacity. So you have the battery, and 3 motors, ( two electric and one gas) all working with an all wheel drive system, and the computer deciding when to kick which or both EVs in, when to kick the gas in, when to send power to the rear wheels or front wheels from which source or sources, and then sending power back to the battery as it decides and breaking doing the same. (The brake pads last forever) Lots of engineering!

  14. E.M.Smith says:

    @David A:

    At our present tariff for over baseline electricity, that’s about 10 ¢ /mile. Looking up the “gas only MPG” said it was 38. So that’s $3.80 /gallon gasoline to get 10 ¢ / mile. Gas here is selling at about $3.85 to $4.10 for RUG; so it would be net making a profit, but only a tiny one. Probably not enough to bother.

    Go to Florida, gas is closer to $2.50 / gallon… but electricity drops to somewhere around a dime, I think… so likely makes a lot more sense in places with low electricity costs.

    Now should I ever get a big RV with a lot of solar on the roof… How’s the Rav 4 at being towed? Does it need a trailer or just a hitch on the front?

  15. H.R. says:

    @Terry Jackson – The Baker Electric was made in Cleveland, Ohio. My Grandparents, by happenstance, had a 1910 Baker Electric. It was the only car my grandmother ever drove. After my grandfather switched to a Ford, around 1916 or so, she never drove again.

    I’m not sure if that garage was built because there would be an electric car in it or if it was just to keep the Cleveland lake effect snow from totaling a wood garage.

  16. Simon Derricutt says:

    A few ideas about how to stop those sparky cars going up in smoke….

    Charging a metal (as opposed to oxides or other compounds) battery is much the same as electroplating. If you do any electroplating, there’s normally a maximum rate of plating above which you start getting a rough surface, because any high spots produce a higher electric field at that point and thus preferentially the metal ions will be deposited there, so you get a whisker (or dendrite) growing there. Since the plating process is basically random, you’ll always get a certain amount of roughness if you don’t do something about it.

    Electroplating technology has two ways around this. One is to reverse the current flow, so that a longer period of slower plating is interspersed with shorter periods of de-plating at higher current, and during the de-plating periods the higher electric field at the points of the dendrites means that they will be preferentially removed and the plating gets flatter and more even. The other way is to add “levellers” or “brighteners” to the plating solution. Often something like sugar or saccharine will be used, but there are better proprietary compounds which are trade secrets. These molecules are attracted to the high-field locations and physically impede the metal ions from passing there, thus you don’t get deposition at the incipient dendrite points and they don’t grow. Slight problem in that the levellers can get broken down by the electric field, so they need replacing, and for the sugars you’ll end up with some Carbon or tarry stuff in the solution.

    The downside of adding the levellers is that the plating rate will be lower since a proportion of the electrode area will be shielded, but maybe there are compounds that won’t degrade in use so it might be OK for lifetime. Similar downside of the short sharp discharge, since you’re discharging the battery for part of the time. Though you’ll lose a bit more energy in waste heat during charging, if you run the high-intensity discharge into a capacitor and then feed that energy back in during the charge part of the cycle you don’t waste energy in a resistor load.

    Could be that the battery designers are stuck in their design system, and expect to charge their batteries at a constant rate and don’t know about the solutions from plating technology. I think they do use additives to inhibit dendrite formation, but the pulsed charge/discharge solution hasn’t been tried. It might fix their dendrite problem.

    Officially you can’t recharge Zinc/Carbon cells (the old D cells I bought as a kid, otherwise known as Zinc/MnO2 since the positive electrode is a mix of MnO2 and Carbon, with a Carbon current collector and Zinc outer case) though you can put a bit of charge back into them with a higher risk of leakage (hey, I didn’t have much money…). However, if you use the pulsed charge/discharge system, you can get around 50 charge cycles without the outer Zinc casing getting a hole and without Zinc dendrites internally. I never tested that out, since such chargers weren’t available when I was a kid and by the time I heard of them I didn’t need them. The design wasn’t good anyway, using partially-rectified AC and thus not a high-enough discharge rate relative to the charge rate. I’d do it using a microcontroller and recycle that discharge energy rather than waste it.

    Obviously current systems don’t use this charge/discharge method of controlling dendrites. Needs some experiments. I don’t know what effect this would have on battery life (number of cycles overall) since it might decrease the life (degradation of the electrolyte and side-reactions) or might increase it (smooth plating and maybe less side-reactions). Seems worth trying, though, given the risk of battery fires.

  17. Steve C says:

    @Simon – I remember the same technique for recharging non-rechargeable cells from when I was young, broke and at school – “Dirty DC” charging, we called it then. If you were using a single rectifier off one end of a transformer winding for your basic charger, you just put a fairly low resistance across the rectifier, so that on one half cycle you get normal rectified current flow, then on the next half cycle you get controlled discharge through the resistor. That simple.

    And yes, it works, certainly on zinc-carbon cells, as I proved myself. First time I’ve seen mention of it in half a century! (Haven’t got a sparky car to check whether it works on lithium batteries, though.)

  18. David A says:

    EM , yes, crazy different rates all over California At 17 cents a kilowatt it takes 7 kilowatts to go 25 miles ( what my old car got) so that equates to $1.20 a gallon. At 4O mpg that’s 11.76 kilowatts, or $2.00 a gallon. Normally my power here would be 24 cents off peek, but owning an Plug in gives this break on all the power except 5 to 9 pm. Of course I try to charge the car during the day with the solar.
    At a jacked up 42 cents it turns into $2.94 for the 25 mpg comparison, and $4.94 for the 40 mpg vehicle.

  19. E.M.Smith says:

    @David A:

    There’s even a tariff in the Central Valley for during hot summers. Time Of Day pricing that rises to $1 / kW-hr during prime A/C hours… Don’t want to be charging up then on that rate plan… ;-)

    FWIW, a general rule of thumb for Diesel Generators is that the cost of the electricity produced (variable costs) is 1/10 of the price per gallon of Diesel. So Diesel at $4.20 / gallon makes electricity at 42 ¢ / kW-hr. Until Diesel goes to $10 / gallon, it is better to run a portable Diesel Generator during those peak rate hours than to buy PG&E electrons…

  20. philjourdan says:

    I read some of the comments about how great the Toyotas are. I have probably owned Toyotas longer than anyone on this list (since 1978). But I have bought my last one. I do not support Woke Companies. Told them so. But woke companies do not care.

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