Re: Bass tracker battery setup
Does it have a trolling motor on the front? Does it say 12v or 24v on it?
If you have a trolling motor, 2 of the 3 are likely for that. If its. 12v system wire them in parallel to keep 12v. If it is 24v you wire them in series to make 24v. Depending on the brand and type of motor, the plug may make the correct connection for you.
The 3rd battery is your engine starting and accessory power.
I have had great luck with the Wal-Mart ever start deep cell marine batteries. If you can fit em in your battery box, the group 29's last a long time. Since you have 2 of em, group 27's may be plenty.
If you don't already have one, I would get a 27 or smaller deep cycle for the starting battery.
If you are running a good sonar unit, it needs to be on its own power source to prevent interference. A small 12v battery like that for a Motorcycle or lawn mower lasts days.
Find some junk batteries for cheap to save yourself the core charges on 3 batteries. $30 each adds up. You should be able to get em free or cheap on Craig's list.