Model 3 MR Battery Degradation

[KenC]

I am the one in the 15% percentile of degradation after 11k miles. I normally charge to 80%, but only use about 5-10% of it in a day. So it goes under 70% maybe once a week? Maybe I should try charging to a lower max %, like 70%? My only issue with this is that Tesla themselves say to charge to 90%.

Since you're showing unusually high early deg, I would take more extreme action. Go for optimal charging. Since you use 5-10%, then set your charge to 60%. Try that and see if there's any difference. If things do improve, then you can inch that up to 70% and if that works, then 80%.

The 90% is considered okay, but it's not better than 80%. Any choice is a tradeoff between battery longevity and battery usefulness. Elon thinks that the slightly worse deg of 90% is a fair tradeoff for the greater convenience. Your battery for some reason doesn't seem to like it, so change up your strategy.

 

[Carl_P]

What Tesla says isn't necessarily gospel. It's just whatever they can reasonably train their employees and what applies generically to the largest percent of customers.

Thanks for your help. I'm always nervous to do something different from what the manual says, but in this case, since my degradation has been bad, I'm willing to try. Do you have a source for something that says leaving it at 80% is the worst thing for the BMS?

 

[gecko10x]

Thanks for your help. I'm always nervous to do something different from what the manual says, but in this case, since my degradation has been bad, I'm willing to try. Do you have a source for something that says leaving it at 80% is the worst thing for the BMS?

Ok, despite my best efforts, I was not able to locate a single post with actual numbers and a good summary, but here's the gist as I understand it (with the caveat that this is all above my pay grade, and is just my recollection of reading other smart people here on this forum):
The BMS calculates your battery capacity by measuring the difference in voltage of the pack from the beginning to end of the charge. Given that the voltage is rather constant from 60-90% SOC (see this post), if you're only adding a small amount of energy all within that range, there's a lot of error in the BMS capacity calculation.

Hope that helps.

Edit: Having said that, I would remind you that this is all a bit of speculation. The assumptions around how the BMS works are just guesses AFAIK, and changing your charging habits may or may not do anything for you.