Battery degradation - 2019.32.2.2

[KenC]

@KenC thar is a great chart. The avg temp where I live is around 44f now and I have lost anywhere between 4-7 miles of range if I charge to 90%. Interestingly enough when I charged over a few cycles to 70% it closed that gap to 3-4 mi. When I bumped back up to 90% it stayed like that for a few charging cycles and then went back to 4-7 mi loss. I see the same difference now on the holiday update (2019.40.50.1).

Is the general consensus that we should not worry and continue charging at our normal levels (90% for me) and as the weather warms up this should recalibrate? Just want to understand if I should be changing my charging habit or levels I charge to or deplete the battery further between charges or bring to a supercharger every once in a while, etc

Thanks

I can only speak for myself, but there's no definitive answer, because there could be several causes for the range to show lower. For myself, it seems to be ambient temps, causing BMS drift. For others it could be updates causing the BMS to lose its place, and for the unlucky few, it could be true battery deg. We just don't know, so there's no consensus.

Having said that, you can only gain confidence in what you are seeing, over time. I only realized there was a temperature correlation after seeing someone else's chart, which looked alot like mine, after about 10 months. Then realized that his car was also in the same geographic region. The constant was the ambient temp.

I've started threads/surveys in the past where I asked people with no range loss, for their charging strategies. There's no pattern. Some charge to 90%, and use SC all the time. Some charge to 60% and slow charge. It doesn't seem to matter. Whatever strategy you want to use, might work. Those with big sudden changes in range, might benefit from a BMS recalibration. And those with real deg, would benefit from getting down to 30% loss and getting a new battery under warranty. That's all I've gathered from reading these boards for over a year.