I was told they did when I took my 2020 Bolt EV in for a diagnostic check of its traction battery. It was a shock to me, particularly after a GM “concierge” staffer told me they didn’t do that when I talked to them before I took the car in. The concierge also told me that I could refuse the safety recall software that limited the usable capacity of the Bolt’s battery by 20%.
If GM installed the new battery management software on my car, they did so without my permission and—more importantly for me–without my knowledge.
That’s not necessarily a bad thing. Who wants their car to burst into flames?
For the time being this is anecdotal. I have no other evidence that GM installed new software on our Bolt other than the battery is limited to 80% on a full charge and all other indications are the battery still has relatively full capacity after 18,000 miles.
Here’s what GM’s service technician had to say: “Normal battery operation following over the air update on battery charge state. Waiting for recall to become available on this vehicle.” The latter is a reference to a replacement battery as part of the GM battery recall. As a 2020 model year Bolt, we’re near the end of the queue for a new battery.
Update: GM does not do “over-the-air” updates for the BMS of the Bolt traction battery nor do they update the software without the owner’s permission. I have confirmed this with GM. I have also identified a bad cell #33 of Module 4 and I am continuing to lose capacity. The local Chevy dealer is grossly mistaken.
Background
Since the advent of the battery-fire recall, I’ve been parking the car in the driveway and not under the carport. If the car caught fire in the driveway it was less likely to involve the house and garage there than under the carport.
I received an electronic and paper message sometime in December 2021 saying that I had to take the car into the local GM dealer for them to install the charge-limiting software. I didn’t act on it and I wasn’t planning to act on it.
While we live in California with one of the densest networks of charge stations in the nation, many of the places we drive the Bolt are remote. Often we need all the range the Bolt is capable of. I didn’t want to reduce the capacity of the battery and effectively reduce the Bolt’s range 20% or 50 miles.
We’ll make do and adjust our trips accordingly. It’s not ideal but it could be worse—I saw a picture of an EV destroyed in Ukraine.
What or Who to Believe
It seems surprising that GM is
- Capable of an over-the-air battery software installation, and
- They would do so without some operator input.
And the very clear message from the concierge that GM doesn’t do this doesn’t instill confidence in GM. It’s either a case of the right hand doesn’t know what the left is doing or someone has simply got it wrong.
There were no other opportunities for a GM dealer to install the software. This was the first time I’ve taken the car into a GM dealer in the 18,000 miles we’ve owned the car. (We have the tires rotated at a tire shop we’ve done business with for years.)
Status
For the moment all we know is that our 2020 Bolt appears limited to 80% of the traction battery’s nominal capacity. The OBD PID is reporting ~58 kWh remaining of the 64 kWh we started with. The calculated usable capacity based on the percentage State-of-Charge is 46 kWh or 80%. Range when fully charged is ~200 miles.
We’re waiting for our new battery.
