You can use them for a trolling motor but three of them wired together is only about 55 amp hours which depending on trolling motor and conditions is approximately 2-3 hours. If were using your trolling motor just to move around a fishing spot then I would say they would be fine, but if you are using the trolling motor for primary propulsion then I would say go bigger. Also be careful on charging these you will need a low current (2-3amps)SLA battery charger to keep these in top shape. Twenty two dollars a piece is a pretty good deal.