Need your suggestions. I have a interstate battery in my tracker that normally lets me troll for 7-8 hours before it runs out of juice. Am using a digital motor guide trolling motor, 12v system, same for past two years. Last two times out battery was dead in less than three hours. Thought maybe battery was bad, bench charged it over night and had it tested twice today, both times said was putting out more than it is rated at, and is still good. Have been using the on board charger that came with the boat until last night. Now I'm not sure if it's the charger, or if the trolling motor is now drawing more current than before. Have made no changes to any wiring, or added anything new. Any thoughts?