mswlogo, that is what I do on days of local travel -- I charge to 60 or 70 percent. Gives me enough range for normal and emergency local driving situations. I do keep it plugged in. That way, if I open a door or something, it takes the power from the wall connector at low amps to power the car even if I have it set for scheduled charging at a different time. I can also hear cooling and heating fans when it is connected sometimes as I walk by, and I am pretty sure these don't run as often when it is not connected. I think it tries to keep the HV battery in optimum condition, summer or winter.