Firmware update battery levels

[Robaroni]

HI,
My 2017 Bolt has just been updated. I was told I don't need a new battery BUT a person at the dealer the same day with a later purchase date was told he does. Why is that and why if my VIN number shows the old battery aren't I getting a new one?

After the update I noticed my battery level is about 40 miles lower in range on both hill top and full charge. Why is that?

Thank you,
Rob

 

[SeanNelson]

My understanding is this:

- The car's onboard software reports any anomalous battery conditions to GM - that enables them to determine if you have any weak battery cells that would require replacing the battery. So I'm assuming that the other person's car must have reported an issue which would lead to the recommendation for a battery replacement.

- When you have the BCM (Battery Control Module) software updated, it needs to "recalibrate" itself so that it provide range estimates. It may need a complete charge cycle to do this, until then the range estimates may be a bit wonky. Of course the other factor is that range estimates can and will vary depending on the type of driving you've been doing recently.

 

[Robaroni]

Thanks Sean,
I'm pretty good with battery algorithms and have been careful with the Bolt, I charge it on 'hilltop' 90% of the time and, because we're retired, we rarely run the battery under 100 mile range so what you say makes sense. The other owner who needs a replacement showed up at the dealer with 48 miles range left.

I'll keep an eye on it.
Rob