darth_vad3r
Well-Known Sith
It's not so much about whether it's at 90% or less than 90%. It's about if you are using a very small band of the charging capacity. When you don't give the system a chance to see a broad range of energy in and out to see the high and low extents of the capacity, it starts losing the ability to calculate that accurately. All Teslas have been that way.
Yes, it’s just this. And this is only a temporary problem until you stretch the battery a bit by using more of the total range ... and then again it’s only a “problem” if you let it bother you
The voltage curve on Li-ion batteries is supposedly very flat during the middle range of the SoC, so if you stay there a lot, the BMS has only tiny deltas in voltage to go on vs larger deltas at high or low SoC. It’s also temperature dependent. Voltage isn’t the only thing they are looking at, but if you handicap one factor it hampers the accuracy of the whole estimation ‘calculation’.