2021 M3P Battery Degrading Question

[royinla]

I am sure this has been previously discussed but appreciate any input. Got my M3P Jan 2021. It was normally charged to 90% and getting 280 miles first couple years. Past year I started getting 250-260 and now it seems to be getting 240 miles at 90% charge which means 100% would be around 270 (vs. 310 expected). Is this normal or something is off? thank you for your replies.

 

[Sophias_dad]

I am sure this has been previously discussed but appreciate any input. Got my M3P Jan 2021. It was normally charged to 90% and getting 280 miles first couple years. Past year I started getting 250-260 and now it seems to be getting 240 miles at 90% charge which means 100% would be around 270 (vs. 310 expected). Is this normal or something is off? thank you for your replies.

240 at 90% would be 266 at 100% (240/0.9)

That's 14% degradation. Worse than average, but less than half what you need before Tesla will do anything.

Maybe describe your mileage and charge habits.

 

[Apprunner]

240 at 90% would be 266 at 100% (240/0.9)

That's 14% degradation. Worse than average, but less than half what you need before Tesla will do anything.

Maybe describe your mileage and charge habits.

Not surprising if you charge to 90% regularly and stays at high SoC.

 

[Gasaraki]

You should try charging it to 100% and using it down low a few times and see if the BMC can recalibrate.

 

[royinla]

240 at 90% would be 266 at 100% (240/0.9)

That's 14% degradation. Worse than average, but less than half what you need before Tesla will do anything.

Maybe describe your mileage and charge habits.

Thank you. I have 56k miles and normally charge it to 80-90%. I drive about 30 miles a day through a canyon so basically up and down hill with many turns if that makes any impact?

 

[Scelto]

If you routinely charge in a very narrow range (say 60-90%) then the _estimated_ capacity of the battery becomes inaccurate over time and doesn't necessarily indicate actual degradation.

When I first got my car, I followed Tesla's advice and left it plugged in all the time it was at home, which with my usage meant it was almost always sitting between 65 and 80%.

I perceived premature degradation, opened a service ticket and had a long chat with their second level support team about how my charging pattern was perfectly fine but didn't give the BMS enough data to accurately guess the actual capacity of the battery.

I changed my habits and over the course of a couple of months (I am a low mileage driver), the reported degradation went from 11.6 to 7.5%, much more in line with fleet averages.

There are some comprehensive write-ups around here about why this happens ("BMS reset" amongst other keywords), but if you charge in a narrow band it's pretty well understood behavior.

 

[royinla]

If you routinely charge in a very narrow range (say 60-90%) then the _estimated_ capacity of the battery becomes inaccurate over time and doesn't necessarily indicate actual degradation.

When I first got my car, I followed Tesla's advice and left it plugged in all the time it was at home, which with my usage meant it was almost always sitting between 65 and 80%.

I perceived premature degradation, opened a service ticket and had a long chat with their second level support team about how my charging pattern was perfectly fine but didn't give the BMS enough data to accurately guess the actual capacity of the battery.

I changed my habits and over the course of a couple of months (I am a low mileage driver), the reported degradation went from 11.6 to 7.5%, much more in line with fleet averages.

There are some comprehensive write-ups around here about why this happens ("BMS reset" amongst other keywords), but if you charge in a narrow band it's pretty well understood behavior.

Thank you ! I will try that

 

[Apprunner]

Thank you ! I will try that

If you don’t need the range everyday, try charging to a lower state of charge. 90% seems excessive especially if you only need 30%. I charge mine up to 55% daily and use about 30%. I charge everyday. Helps keep the degradation much lower.