Re: how to charge
If you are using a trickle charger to charge three batteries, understand that two of the three must be connected in parallel) because there is only BAT 1 and BAT 2 on the switch. Also understand that a trickle charger has a 1.5 - 2 AMP output so if the batteries are the least bit low, that charger might actually be damaged because it is being forced to run nearly continuously. That would depend on the quality of the charger. Here's a plan -- connect the charger to th COM terminal on the switch. Now you set the switch to BAT 1 to charge ONLY BAT 1. Set it to BAT 2 to charge ONLY BAT 2. Or set it to BOTH to charge BOTH batteries. How about the third one? Well, as I said, to use the switch for charging or any other purpose, since there is only A BAT 1 and a BAT 2 position and you have THREE batteries, two of them must be in parallel. Therefore whichever terminal those two are connected to on the switch is what will charge when the switch is in that position. Lastly, attempting to charge three batteries from the outboard engine while running is nearly impossible unless you run wide open for hours. The engine alternator is designed to keep the starting battery charged and possibly a not so deeply discharged second battery. But definitely not three.
