Thread: Battery Question

Sure a lot of variables there. I have the same trolling motor on the same boat with a 60hp Mercury. I am running 2 group 27 batteries. It is a pretty efficient motor. It would depend on how long you wanted to stay spot locked and gow hard it was having to work to keep you in place. At 50% power that trolling motor draws approximately 20 amp. A group 27 battery depending on brand shows to be rated at 80 to 100 amp hours. At 50% power it would run 4 to 5 hours depending on which battery. It is all tradeoffs. I am running 3 batteries 1 cranking and 2 trolling in that same size boat. I had looked into lithium for the trolling batteries they would save weight in the battery compartment and a fella's wallet. I would say on average you could get 3 to 4 hours running out of one battery. I have been out on days when the motor was running at 9 or 10 on spotlock to keep up with the current and wind. Other days it would run at 2 or 3 to maintain position. I went with 2 batteries to have the capacity to fish all day if they were biting good. Once the battery is getting depleted the voltage starts to drop down. That will cause the motor to pull more amps to do the same work. That produces more heat in the motor. On the scale on the trolling motor I rarely use the batteries down to 50%. They get plugged in a charged when I get home

DockshootingJack thanks for the great straight shootin answer. I have a regular cranking battery for the motor and keep a dedicated batteries for the trolling motor. I did have 2 group 29's for 12 volt. One more question If I go back to two batteries I will get 2 27's. With both hook up together and you hook up the charging cables to one battery do you feel both batteries are getting charged the same?
Also my 29's had 114 amp hours each.

one battery want charge more than the other one...it will only be as good as your weakest battery...

I have a 3 bank charger. One hooked to each of the trolling batteries, the remaining lead hooked to the cranking battery. Trolling batteries remain hooked together while charging

Anytime I have run a boat with only one trolling battery, I always took a spare. Never know when you might need it if the first gives out. Also used it to run crappie lights, replace the cranking battery the few times it went dead on me. etc. If you start trolling and the wind kicks up, may need the extra.

Originally Posted by DockShootinJack

I have a 3 bank charger. One hooked to each of the trolling batteries, the remaining lead hooked to the cranking battery. Trolling batteries remain hooked together while charging

My 3 bank charger is wired the same....one bank to each battery.

DSJ did you good on his report. It's all about how much time you want to spend on the water; wind speed, current, weather temp, etc. My suggestion is two 27s or 29's in parallel for the trolling motor, and a third battery for crank and accessories. Good luck!

I am getting 2 group 27 everstart at Wallmart. Problem is at 3 Wallmarts can only find one. Gonna keep trying hoping another one comes in.