I have 2005 vintage twin Yamaha 150HP outboards use a flywheel to create a charging current different than an alternator. I'm using Dakota lithium batteries for both house and starter batteries. Can the current from the Yamaha engines be used directly to charge LiFePo4 (lithium) batteries or does some DC-DC current limiter or some other device need to be put between the batteries and the outboards? What happens when the batteries are fully charged? I have heard the flywheel based chargers are water cooled and I don't need to worry about them. I have no data to know if both the engines and batteries will be ok if directly connected and if they won't - what can work that won't greatly limit the 90 Amps or so charging current the engines can produce. It is counter productive to put something in there at will limit the charging current to 15 or even 30 amps unless necessary. Any recommendations or education here would be greatly appreciated.