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Under the hood of Chevy's Bolt battery fire debacle

Although recalls of this magnitude are not unique to EVs, General Motors is spending an estimated $1.8 billion, or around $12,700 per car.

Chevrolet Bolt

A Chevrolet Bolt EV electric car charging on display during Los Angeles Auto Show in 2019.

Certainly the biggest EV story this month is the Chevrolet Bolt battery recall saga. Given the battery heating issues I’ve personally encountered with my Nissan Leaf, I was curious to dive deeper into the story.

Is the reason for this recall unique to the car and its battery? Is this a Bolt-only issue, a one-off or is this a bigger problem with potentially far-reaching impacts that could present itself in other EVs such as my own?

While the most recent development came last week, the saga of the Bolt’s combustible battery began last October, when the National Highway Traffic Safety Administration (NHTSA) opened an investigation into the EV due to reports of battery fires while plugged in and unattended.

According to the NHTSA, the vehicles held the potential to "catch fire even if they are turned off, parked, and disconnected from a charging unit." General Motors soon followed that revelation with a recall of 50,932 Chevrolet Bolt vehicles from model years 2017-2019, citing the potential of an unattended fire in the high-voltage battery pack underneath the back seat’s bottom cushion. Fast forward to Aug. 20, and GM has expanded the recall to include all Bolts from model years 2017-2022. 

Although recalls of this magnitude are not unique to EVs (an important thing to note) and are relatively common in the automotive industry (especially for new vehicles), GM is spending an estimated $1.8 billion, or around $12,700 per car, on this recall alone. A costly sum, for which the automaker is seeking compensation from the battery maker they say is at fault, LG Energy Solution (a subsidiary of LG Chem).

Design deficiencies arose when 'they tried to shove too much battery in too small of a cavity, trying to maximize battery life.'

According to the Chevrolet Bolt Recall website, "experts from GM and LG (the producer of the battery) have identified the simultaneous presence of two rare manufacturing defects in the same battery cell as the root cause of battery fires in certain Chevrolet Bolt EVs." GM’s media site states that the two identified manufacturing defects were "a torn anode tab and folded separator — present in the same battery cell." 

What do these technical terms mean? For insight, I spoke with Doug Campbell, CEO of Solid Power, an EV battery startup out of Colorado backed by BMW Group, Ford Motor Company and Volta Energy Technologies. He compared this battery debacle to another one in a different industry, cell phones. 

Recall the exploding Samsung Note 7, which was pulled from the market? Essentially, design deficiencies arose when "they tried to shove too much battery in too small of a cavity, trying to maximize battery life," said Campbell. He said what causes the explosion into flames — the ignition source — is the liquid or gel electrolyte that you see in today's lithium-ion batteries. In regard to EV batteries, this means that in the event of an accident (or manufacturing defect), there’ll always be a risk of fire due to the battery pack in an electric vehicle. In the case of the Bolt, the battery could ignite if left to charge over 90 percent, is charged more frequently or is depleted below about 70 miles.

Solid Power aims to completely eliminate this issue with the creation of an "all-solid-state-battery." That format, as the name indicates, does not include any liquid components. Removing liquids from the cells is also expected to drive down manufacturing costs, cut production time and could reduce cost at the battery pack, according to the company. With so much at stake, it seems like a smart move for BMW and Ford to expand their existing joint development agreements with Solid Power to secure all-solid-state batteries for future electric vehicles.

So what does this mean for my Nissan Leaf, or any other EVs for that matter? Should I be concerned about this issue happening with my car?

Technically no, given this Bolt battery recall looks to be a product of an LG production problem, and my Nissan’s battery was manufactured by the Automotive Energy Supply Corporation (AESC). But I’m definitely looking forward to the peace of mind that will come from eventually driving cars with combustion-proof batteries. 

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