Battery for Bow mount trolling motor

[davidj65]

I currently have a basic 55lb MinnKota in the stern that I use for shallow water and edges, just nosing around coves and such. Runs all day with that level of use on a group 31 Interstate 12V lead acid battery, which also powers the house stuff (lights and sonar and 12V phone charging ports). No spot lock, I use an anchor.

I'm planning on upgrading to a bow mount Terrova and use the spot lock instead of the anchor. The troller will obviously will be running a lot more than it currently does. So I am wondering, what can I expect for battery life? Do I need a couple batteries to get through a long day of messing around?

I like the idea of the LifePo batteries but don't know much about them. The lead acids have been fine for me in my very limited experience, but I'm not tied to them. Ditching some weight would be good. Can the lights and sonar also be run off a Lifepo?

I know some people say not to run sonar off the same battery as a troller, but so far I haven't had any issues with that.

 

[airshot]

I have a 55# MK with spot lock on my 16' Sylvan side console. It runs on two dedicated group 31 lead acid batteries. It can last for up to 8 hrs depending on how hard it is used. When these 6 yr old batteries give up, I will replace them with a single 140 ahm LifeP04 battery and expect to get similar or longer run times. I also have a dedicated start battery for the motor and a group 29 deep cycle for all accessories as a house battery. LifeP04 are great...but MUST be handled correctly with storage and handling.

 

[FuzzyGrub]

I highly suspect that your current G31 will be fine. Try that first and check the voltage level before you put the charger on, at the end of the day. If you find it is deeply discharged, then that would indicate you want a large capacity LiFePO4. My guess is that your stearn trolling motor is fixed speed selectable, which are not as efficient as your new Terrova. So you gain a little there.

If you use or plan to go with one of the newer "Live" or forward scanning sonars, they tend to be power hungry. That could drive you to two batteries.

You didn't mention it, but if your battery is connected to the motor, it will take a special LiFePO4 that can handle the charging from it. As Airshot mentioned, there are some extra precautions using LifePO4, too.