On Fires, Electric Cars, and General Motors

Bolts have been catching fire. In their response to these fires, General Motors has taken an incremental approach that is seriously damaging their reputation and the reputation of electric cars in general.

To recap what you probably have already learned from other sources: the battery packs in a small number of Chevrolet Bolts – GM’s iconic small electric crossover, and the car this website and blog are based on – have caught fire, totaling the cars and damaging or destroying their owners’ garages. GM has dealt with this through a series of recalls. The first of these recalls, widely advertised as “temporary,” installed a simple software patch that prevented the cars’ batteries from charging to more than 90% full while the problem of the fires was being researched. The second, five months later, was more complex: dealers’ service departments tested the car’s batteries for cells that exhibited what GM’s engineers thought was the flaw that caused the fires, replaced any battery modules where the defect was found, and installed new battery-management software that watched for the flaw and warned owners if and when it developed. This was announced as a “permanent” fix.

It wasn’t. Fires continued to be reported, including at least two in Bolts on which the “permanent” fix had been performed.

Last week, GM announced a third recall. Armed with new theories about what has caused the fires, plus statistical information on the dates of manufacture of the burning vehicles, they plan to check certain ranges of VIN numbers, aggressively retest the batteries, and replace every module that shows a hint of the problem, up to and including entire battery packs, if necessary. This is a laudable upscaling of their response.

It isn’t adequate.

Before getting into the reasons for that, it seems necessary to dispel a few misconceptions about the fires. The first has to do with their frequency. As of the last report of which I’m aware that gives actual numbers rather than estimates (Green Car Reports, 7/23/2021), nine Bolt battery packs have caught fire. Almost 100,000 Bolts have been sold in the United States since the car was introduced in late 2016. Even if we limit our scope to the early run of the 2019 models, when the overwhelming majority of the cars involved in the fires were manufactured and sold – the last four months of 2018 and the first four months of 2019 – we are dealing with a maximum of nine fires out of more than 13,000 vehicles. That is not exactly a high-risk percentage.

The second misconception is about who is to blame. Although GM is correct to recall the cars – and Chevrolet technicians will be doing the work – the auto company did not manufacture the faulty batteries. Like almost all cars today, Bolts are a conglomeration of parts built by various subcontractors in various parts of the world. The batteries were built by the giant South Korean chemical and electronics firm LG Chem, and all of the defective units discovered so far have come from a single LG plant, in Ochang, South Korea. LG has partnered with GM in the various recalls, but so far they have adroitly managed to sidestep public responsibility. This should change. GM should no longer have to take a fall for another company’s shoddy workmanship.

The third misconception is that the fires have been random. Actually, almost all of them have taken place under the same circumstances: they involve batteries that have been discharged nearly to zero and then taken to completely full in a single charge. This is normal refueling behavior for drivers who have learned their habits in gasoline-powered vehicles, but it’s wrong for lithium-ion batteries, which do best on many shallow discharges rather than on a few deep ones – meaning that they should be recharged at every opportunity instead of only when the car’s range drops so low that a charge is necessary to make it to the next charging station. Batteries also heat up while being charged, behavior that gets more extreme during the last few percent of a full charge. This last characteristic is why GM’s original quick fix was to install software that cut off the Bolt’s charging at 90 percent, and it is also why the company currently advises owners to use the car’s native charge-limiting settings to reinstate that 90 percent limit while waiting for the most recent recall to be performed (they also suggest that the available range shouldn’t be allowed to drop below 70 miles, to avoid the deep discharges that seem to be a large part of the problem).

So: if the fires are extremely rare; if the risk can be minimized even futher by proper battery care; and if it isn’t GM’s fault anyway, why do I consider the current recall – which is solely to detect and replace battery modules exhibiting the fault that GM and LG engineers now believe to be the real cause of the fires – seriously inadequate?

Full disclosure, here: my own Bolt is a 2019 with a battery from that suspect South Korean plant, and with manufacture and sales dates (August and December, 2018) that put it right in among the cars that have been most likely to burn, so these things are likely to influence my state of mind. But that is precisely the point. A recall like this is certainly about safety – no one wants to see more Bolts catch fire – but it is even more about state of mind. The actual risk that any given Bolt will catch fire is vanishingly small; the risk that it will catch fire during the next 24 hours is even smaller. As an environmental writer, and the son of a scientist, I understand the minute nature of these risks quite thoroughly – intellectually. I still go to bed each night with a niggling fear that I will be awakened by a smoke alarm, and I now shy away from taking trips that will run the battery gauge below five bars (out of twenty) before the next charge begins.

The currently announced recall isn’t going to change that. Testing for faulty modules and replacing them might have seemed adequate last time, but that last time turned out to be a failure. It did not breed confidence that testing and replacing individual modules will do the job now. To regain consumer confidence in the product, nothing less than full replacement of every questionable battery pack will do. This is especially true of the early 2019 models that have experienced the great majority of the fires, but it is actually necessary for every first-generation Bolt battery built in the Ochang plant. All of them are now suspect. Whether or not that suspicion is deserved is beside the point: Bolts – and, by extension, electric cars in general – will remain under a cloud of doubt until and unless full replacement is done.

GM needs a recall designed by politically savvy engineers. It has given us one designed by accountants and lawyers. It apparently aims, not to protect Bolt owners, but to spend the least money possible to gain the company the greatest possible protection from lawsuits. On that last point, GM’s own language in the recall notice is instructive:

Out of an abundance of caution, you should continue to park your vehicle outside immediately after charging and do not leave your vehicle charging overnight.

This is in direct contradiction to the advice given in the owner’s manual:

It is recommended that the vehicle be plugged in when temperatures are below 0°C (32°F) and above 32°C (90°F) to maximize high voltage battery life.

To paraphrase that last statement: leaving the car plugged in will allow its battery-management tools to do a better job. If that is true, then unplugging it and moving it outside will cause those tools to do a worse job, which will increase the risk that the battery will catch fire. Only a corporate lawyer would advise making the risk of a car fire greater in order to reduce the liability risks to his client should the car fire cause its owner’s house to catch fire as well.

I am continually appalled at the damage fossil-fuel use does to the environment, up to and including climate change. I also love electric cars for themselves, and I particularly love the Bolt. It would be a shame if excess financial and legal caution on the part of General Motors led to fewer Bolts, fewer electric cars in general, and an increased likelihood of runaway damage to the planet.

Update on August 20 – General Motors has just announced that all battery modules in all Bolts will now be replaced (including those in the new extended version known as the EUV). They are “aggressively seeking” compensation from LG for the costs they will be incurring. The new modules will be the current version, so those of us driving older models will see an 8% improvement in range, as well as receiving an updated warranty that will cover the new battery modules for 8 years or 100,000 miles. I’m happy to see GM stepping up to the plate on this one.

2 thoughts on “On Fires, Electric Cars, and General Motors

    • Thanks, Jonathan. I think you and Rosy are going to love the car. The pre-2019 Bolts don’t have the ability to charge to a certain percentage, but they do have something called “hilltop reserve” that cuts off the charge at roughly 88%. I highly recommend that you use it, not only to reduce the risk of fire but to allow the use of one-pedal driving from the get-go. Drive it in L and you’ll see what I mean (we personally never use D).

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