When I dropped my car off for contactor replacement, it had about 40% SOC on it. For some reason, they pulled it inside and plugged it in, charging it to 90% (I could see this on my mobile app from home). Probably some "default" protocol when someone drops their car off and leaves it overnight. When I got the car back, it had over 100 miles added to the odometer (I always record the value whenever I take any of my cars in for service), so I guess I know how they drained it before working on the pack!