I have a '19 M3 AWD with ~38K miles. When sitting idle, I see that sometimes I lose some percentage of charge, but also sometimes gain. The car is sitting in my garage and the idle time varies from a couple of hours to a day. See the energy screen below. Notice there's around a 5% drop in charge at about 38 miles driven. Then there's a couple percentage gain around 68 miles. Is the battery recalibrating when idle or what? Thanks for any thoughts on this.