"You will need a heavy duty ba
"You will need a heavy duty battery switch ($110) and battery cable. Perco is a popular brand of switch but there are also others for same price. The switch will allow you to turn off all battery supply, run one or both battries. Mount the swith in a easy to get to location.
Usual battery hookup is positive of each battery going to the switch. One positive going from switch to engine supply. One short negative connects battery to battery and one long negitave going from battery to engine ground but follow the directions that come with the switch.
I currently use deep cycle batterys only because they will crank hard all the way to dead however, they tend not to last over one season of hard use.
You are most certainly correct about leaving something turned on and just as the sun sets, ya go to start the old girl and all you hear is CLICK!"