I leave stuff plugged in to charge over night and when I forget on Fridays they can stay plugged in all weekend. Because I charge stuff like my blue tooth head set the inverter needs power all the time. I have left this plugged in a weekend before and have had no issues at all starting. I leave it plugged in over night all the time. I'm not sure how long it would take to drain the battery if it was just left on with nothing plugged in but it would take a while. For idiot proof just get a better inverter one that has a sleep mode and could also monitor the battery condition and shut itself down before it drained beyond what was needed for start up. One of the reasons for using the inverters own outlet was to maintain the lights and switches that came with it. But my first mounting position would not fit so when I moved it the lights were now to short. I will just make sure nothings plugged in for to long and the battery will be fine. This is also why a second battery is on the mod list.