So one day last week, I charged my S75D up to 80% at home in the morning before leaving, and when I arrived home later that night, my battery was at 31%. So almost 50% used. When I looked at the kWh it said I used during the day, it only reported 27 kWh. I know the 75D does not really get a full 75 kWh, instead something around 70. But using almost 50% of my battery that day, I would have expected the kWh used to be close to 35 or so. Is the battery % used not on a linear scale?