what trolling batt is needed

[leadcore troller]

I'm putting an electric trolling motor on a 17ft boat. It's a Navigator 5200, that mounts on the cavitation plate of the outboard. Was wondering what size marine deep cycle batt should I buy, Someone told me a group 27 . Also I guess it would be a good idea to install a battery selector switch for 2 batteries, so the outboard could charge it and not drain down the boats batt. Any info is greatly appreciated.

[Xxx]

Yes you will need the group 27's, the 24's will be two small. Here's the kicker ( I owned and operated a starter & alternators shop, and sold litterly thousands of batteries) if you use the alternator to charge up your strictly deep cycle batters they are designed to discharge slowly and they are to be charged slowly, if you ever noticed on certain battery chargers they have a 2amp charging spot then they have a deep cycle selection. Long story short is the deep cycle battery will begin to get a memory, slow discharge fast charge back, soon you will notice the batteries aren't lasting as long. They will start to discharge faster and faster till one day they won't be any good at all. Don't ask me why its something in the surface charge and the alteration of how the batteries were meant to be charged, and a alternators blows back 14 volts at way to high of amperage. I have the Optimax yellow top to run all my electronics, and my alternator charges two group 27's one is a strictly starting bat. The other is a start/ deep cycle that I run my riggers. With the Perko selecter I charge my main then if my rigger battery goes down below 10v with the motor off I select both and they become charged equally. Hope this helps!!

[leadcore troller]

Pap, Thanks for the in depth knowledge on the batteries. Now what should i purchase, the boat only has the big knob switch for batt on/off. So i'm guessing i need a batt selector modle switch instead of the current one, and is the yellow top a batt or a charging aid.This trolling under power is all new to me, I have been trolling the resies for 40 yrs , oar power only.But i do have an electrical background.

[Xxx]

Hmm, I know there are some onboard charging systems but I'm not fully informed wth there function, I know my uncle has them on his boat, but I'm pretty sure they charge his deep cycles from a 110V source. but you might have to get a Perko switch with B1-B2-All so you can start on your starting batt. Then troll with BAT.2. I'll look into the differant chargers.

[Xxx]

From my understanding there's no easy fix, that's why we put kicker motors on to troll, if your going to use them to troll the only thing I would suggest is to troll with one battery until it will no longer perform well. Then double the time. If you use the motor as a means to stay along a break or weeds they'll last a long time. I don't know how long the batteries will last on a constant troll?

[leadcore troller]

I have plenty of chargers, i'll just set them at 2 amps and slow charge it back up at the end of the day. not looking for a long term fix just for a week or so for vacation this july.