You'll never see any boat dealer run anything off the trolling motor. Believe it or not the bilge and aerator pumps use more power than lights. if you were gonna fish tournaments, I'd tell you to install a PROAIR system. It goes a long way towards keeping fish alive. I've owned a lot of boats. once the batteries are charged I unplug them. Maybe the night before a trip I plug them back in to see how they are holding a charge. If you have a bad battery you'll find one that isn't fully charged. Best to find it before heading to the lake. If possible I'd install a two bank onboard charger. Its a real pain to drag chargers in and out, its even worse once you've had an onboard and only have to run a power cord. good Luck