I leave my CT for several months at a time which leads to the obvious discharge problem. I now have a trickle charger attached to the +/- terminals and have it plugged into the garage outlet with no problems. When it discharged the first time, I was able to 'jump start' it with a Cobra CJIC 350 battery pack. Driving for an hour was effective in charging the battery. Also was able to use a solar panel to keep the battery charged but this won't work if dirt, leaves, snow accumulate.