AlanSubie4Life
Efficiency Obsessed Member
I.e. if the car thinks that its battery capacity is 60 kWh, and you charge from 50% to 100% at the end of your experiment and put 35 kWh (instead of 30 kWh) in, then that suggests that the BMS has gotten off by 5 kWh.
There’s nothing in the car that allows you to measure this. There is just the kWh added number, which is just the number of miles added * the Wh/mi constant. And even that formula is incorrect if you’re above the degradation threshold!
In short, the kWh on the screen is not a good measure of how many kWh were added to the battery. Close, usually, but won’t be helpful for this purpose. You can just look at how many miles were added and that is completely equivalent, even if the BMS was super confused and the actual amount of energy added was far different than what it displays (due to BMS drift that it figures out/resolves on the 100% charge).
I know, pretty confusing.
Pretty much all you can do in this case is see how much your predicted 100% charge shifts (and try to minimize the potentially large error on that extrapolation if not using SMT), and compare to the actual 100% charge value.
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