AlanSubie4Life
Efficiency Obsessed Member
Quick update. Charged to full (99%, wouldn’t go higher), Tesla showed 315 on the range indicator. With the additional data Tessie now shows 3.1% degradation. Tessie tells me that 77.5 kWh were added from 4-99%. I think all is well! Might have been a combination of lack of low end and high end bms data as well as lack of overall data for Tessie. Cheers!
Yes. It is fine. Not sure what Tessie was reporting, but this is layering on a bunch of confusion you don’t need.
If your car shows 315 rated miles at 99%, you’re very likely at 80.6kWh or above (you cannot tell easily if you are above 80.6kWh, though it is possible with careful metering during a drive). It really just cannot be otherwise. Just the way it works. The BMS is very strict about this display relationship.
I am not sure how the Tessie 77.5kWh number is measured, or where it came from. It seems off by 1kWh.
The constant is ~80.6kWh/315rmi.
If you charge from 4% to 99% that is 95% of 315rmi, or 299rmi (if you toggle the range display you can see the miles added (or kWh added) during the charge event on the screen in the car, as long as the car remains plugged in).
299rmi*80.6kWh/315rmi = 76.57kWh
So I think the screen would have displayed 77kWh for energy added.
Anyway, as discussed earlier, from 4% to 99% most likely the actual energy added is closer to:
0.95*0.955*80.6kWh = 73kWh
It may have been slightly more depending on exactly the capacity of your pack.
There’s a buffer of about 3.6kWh below 0%. Which you cannot safely use.
I have no idea why Tessie says you have lost capacity. You certainly have not lost anything significant yet.
I would go ahead and tap the initial value in the Tessie app and enter 80.6kWh or so as posted earlier.
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