Golf8621204
Member
10 month owner - Something similar happened to me, but only once. After I parked it, it sat in the garage for about 48 hours. The battery consumption was something like 12 or 13% with everything off, which never happened before, and the car was asleep. Most of the time when I park it overnight, the SOC% is the same in the morning.
I concluded the BMS had just miscalculated my SOC and/or the cells of the pack had sufficient time to level out,, which caused the updated lower SOC.
As a general rule to keep my battery calibrated, I let the car sit at different SOC's so the BMS learns these different levels accurately. Haven't had any issues since. I also allow my car to charge to 100% once every 3 months, when I know I'll be driving it shortly afterwards. That helps to maintain the battery's total capacity, or at least helps the BMS learn exactly where the top of the pack is, so it can re-calculate range to a more accurate figure. I've always picked up a few miles of total range after doing this.
I concluded the BMS had just miscalculated my SOC and/or the cells of the pack had sufficient time to level out,, which caused the updated lower SOC.
As a general rule to keep my battery calibrated, I let the car sit at different SOC's so the BMS learns these different levels accurately. Haven't had any issues since. I also allow my car to charge to 100% once every 3 months, when I know I'll be driving it shortly afterwards. That helps to maintain the battery's total capacity, or at least helps the BMS learn exactly where the top of the pack is, so it can re-calculate range to a more accurate figure. I've always picked up a few miles of total range after doing this.