Trolling motor battery question

fishKILLA87

Recruit
Joined
Aug 3, 2019
Messages
1
Hi all, getting close to wrapping up my 82 Starcraft 16SS project. Mounted the trolling motor today, and got to thinking. I'd like to run 2 batteries for the trolling motor, one mounted under each console. Has anyone done this? Is it unwise to rig 2 deep cycles in parallel that far apart from each other? The jumpers would be about 10' or so long. (battery under each console, jumpers running in a "V" under the bow seats).

3 batteries at the stern seems like a lot of weight, and I'm concerned about planing ability with my 50hp Yammy. Also, I'd rather not have to fork out the cash for 35ft of 4AWG to make the runs to the stern.

If its possible, what gauge wire should I use for the jumpers?

Thanks in advance!
 
Last edited:

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Use a Blue Seas 12/24 plug/receptacle, with each battery wired separately to the receptacle. The plug can be jumpered for 12V (or 24V), and when you insert the plug, it makes the parallel (or series for 24V) battery connection.

Google "blue seas dc wire calculator" to figure out the wire size needed. Input total wire length (positive and negative) for one side, 3% voltage drop and variable load. You'll need to know the max current draw of that TM. I'm guessing 8ga, possibly 6ga wire. genuinedealz.com has great prices on real "marine" grade wire and terminal ends, quick shipping too.
 

pascoea

Seaman Apprentice
Joined
May 8, 2017
Messages
44
I assume you have a 12v trolling motor? From an electrical perspective, you don't really want to leave lead acid batteries in parallel for a long period of time. The small differences in voltages/internal resistances etc will cause them to "fight" each other, and will shorten battery life. I'm sure others will disagree, but this was just my personal experience from a while ago, so take that for what it is.

As far as mounting them up front, that's what I did. One on each side, just in front of the consoles, wired in series for my 24v trolling motor. I've got a '84 16ft aluminum fishing boat, 75hp. (I have the starting/engine battery in the back)
 
Top