HI BO'S'N
Some how over the years while working with many BO'S'N'S, I got the impression that they were like MARINE WARRENT OFFICERS.They had a little knowledge about a lot of things and dangerous to boot.
But then again I did find a lot of MWO'S THAT NEW LITTLE ALSO!!
just a little service rivalry.
IN REGARDS TO your battery problems 1st- install two [6volt] golf cart batteries on the oposite side of your compartment 2nd- These [must be in series] +to- which will give you [12volts] 3rd Hook your + lead to your existing + lead with a long battery cable 4th ground your new set of batteries to the vehicle where they are installed.Make sure it is bare metal you hook to.
Install proper battery covers with vent holes,also vet the bottom of your battery box with a small hole for air circulation. Remove your existing tube that is for only one battery and install a small 12 volt fan where it was attached to the vehicle body.
I used an old computer fan which fit perfectly and it draws all the fumes out of the battery compartment just as a fan does in a battery shop.You can attach an on and off switch in line so that when you aren't chargeing the batteries it doesn't draw any current.Wire the switch directly off of your 12 volt battery.
I also purchased a 700 watt gen.off of ebay that is also a 12 volt charger for $136.00 plus 30.00 shipping.
It is a 2cycle unit and really quiet.
Good luck to all!
E