Because the BMS may recalibrate during that period, in the same way that a battery can adjust up and down whilst parked. So energy added may also include some of the uplift from recalibration I've seen over 100% charge before although I think TeslaFi now caps that at 100%, and I've also seen some pretty poor efficiencies too which come from a downward recalibration. These anomalies are more easily seen with larger charges where the recalibration is a more significant proportion of the overall charge.The odd thing is that looking at several charges in Tessie shows 100% for some charges and down at 84% for others. I don’t see how you can actually have 100% … that is exactly the same amount added as the charger used. (All on ac home charger) something appears to be amiss, at least for the 100% ones.