I’ve seriously considered this, as I do a lot of boat-in camping. I looked into the MinnKota alternator chargers but ruled them out after talking to them. As I understand it,the problem with them is that they do not switch on until the alternator reaches a certain minimum amperage output. Here’s what their owner’s manual says:
CHARGING REQUIREMENTS:
“In order to achive full output from the DC Alternator Charger, the minimum input from the engine alternator must be as follows:
MK-1-DC: 12 amp minimum
MK-2-DC: 25 amp minimum
MK-3-DC: 35 amp minimum”
My Yamaha 50 manual says the maximum alternator output is 17 amps. I asked Yamaha what rpm’s it would take to reach the MinnKota 12 amp minimum, but was told they’d have to contact Japan for that info, and they didn’t seem at all interested in doing so.
The Yaninda battery combiners, on the other hand, don’t spec a minimum amperage output from the alternator. They just switch on whenever either battery is receiving a charge. That sounds like it should work for me. I plan to go the the Mpls sportshow and ask some more questions.