If the charger turned off, it is my experience that it will not just "turn on again" and start a cell balance. If it wanted to cell balance, it would do it and still show "charging" the whole time. So, there's no benefit to leaving it plugged in. All it will do is once an hour pop on, see that the cells are "full" and pop off again. So, I tend to unplug mine once I see that the charging has stopped. Why chance a power surge or thunderstorm or something?