Re: best deep cycle battery for trolling motor
Group 24, 27, and 29 are the physical sizes of the battery. 24 is the smallest and 29 is the largest. Reserve capacity is the amount of time the battery can power a 20 amp load. Obviously the bigger battery has the most capacity but not all group 29 batteries for example will have the same numbers so watch for that. Without knowing how big your trolling motor is we can't tell you how much current it draws but I can give some relative numbers. If your motor is in 40 - 50# thrust range it will draw "about" 42 - 46 amps when set on the fastest setting. Therefore, if your motor is set to fast, and it draws 40 amps (roughly) and you have a group 29 battery with 200 minutes reserve time, you would discharge the battery in about an hour and a half. At half speed (20 amps) it would run about 3 hours. The story in all of this is that when it comes to trolling motor batteries, buy the largest capacity deep cycle you can afford and have room for and charge that battery immediately after every use (not the next day, or next week, -- immediately!!!!).