I suspect this is a dumb question but i cannot seem to set max charge level so that the car stops charging at the level selected -- ideally 70% or 80%. The software appears geared around timers and days and a regular charge time, which i dont have. The system has a charge level setting, which suggests it would stop charging when that level is reached. The owners manual is remarkably unhelpful on this point. What am i doing wrong?? Please help me figure this out... Obviously, i could do it manually by watching the clock and keeping my phone in hand to turn off -- not ideal.