Not sure if you're towing or docked? If docked, ignore this, but if you trailer your rig here & there, you should look into this set-up:
StayNCharge by Retrotec
With this system, you plug your boat in when you pull off the water and by the time you get home, or to your next fishing destination, your batteries are fully charged and you're good to go again.
I've had this installed on my boat for 4 seasons now with the original batteries; charging one series 27 and one starting battery together. Have never had a problem. My trolling motor is a 12V model, but StayN'Charge has various models to accommodate just about any 12V, 24V or 36V system.
You do not have to hook anything up to your boat when you get home. It's all taken care of by your tow vehicles charging system. No heavy on-board charger to worry about either. Works for me.
