The capacity of our replacement traction battery has declined 6% to 7% during the seven months since it was installed. During this time, we’ve driven more than 6,500 miles, including one 1,500 mile road trip.
Our 2020 Chevy Bolt’s traction battery was replaced under warranty on 6 May 2022 by our local Chevy dealer.
The new traction battery now has a capacity of 58 kWh or 62 kWh depending upon the measure used. Torque Pro is reporting 182 Ah, down from 194.3 Ah logged when I picked up the car.
I’ve written previously on the slight battery degradation found on our Chevy Bolt. See Capacity of 2020 Chevy Bolt with 2022 Replacement Battery after One Month, Battery Degradation 2020 Bolt Relative to 2017 Bolt EV, and 2020 Chevy Bolt EV Battery Capacity Anecdotal Observation.
Tracking Battery Capacity
I record three measures of battery capacity whenever I charge to 100%:
1. OBD PID for Bat Cap Est from Torque Pro,
2. kWh consumed & State-of-Charge, and
3. Bat Cap Raw Ah PID.
I also sometimes record the OBD PID for Bat Cap Est and the Bat Cap Raw Ah PID during partial charges.
I won’t explain what these are here. I’ve explained them in previous posts with the exception of Raw Ah PID. I am now recording the Raw PID for Amp-hours since this is used by GM to measure capacity. As you can tell in the accompanying chart, the Raw Ah PID tracks that of Bat Cap Est PID as you would expect if it is used by the car to calculate kWh.
As others have noted, measures of battery capacity fluctuate from one charge to the next, though there is a general decline in capacity.
Sometimes capacity increases from one charge to the next. For example, the Bat Cap Raw PID increased from 57.9 to 58.2 kWh during the last three charges.
Similarly, during the same charge sessions, the measure of capacity using kWh consumed and SOC rose from 59.7 kWh to 62.3 kWh.
Likewise, Bat Cap Raw PID rose from 181.0 to 182.0 Ah.
I don’t baby the Bolt. I charge to 100% whenever I need to go out of town. And I’ve driven the SOC down to less than 15% on two occasions.
The Capacity Now
We have somewhere around 60 kWh capacity remaining after seven months use and more than 6,500 miles of travel.