I have a single battery system and would like to add a lithium battery. I want the system to be as automatic as possible. The boat uses a stator for charging and I don’t want the lithium to burn up my stator. I’ve looked into an ACR, VSR, and a DC to DC charging device , but I can’t figure out what to use for this set up? The main reason for the additional battery is for the sand bar and using the stereo system. I have a Noco charger when the boat is home on the trailer and don’t need much while on the water. - Michael
When mixing different battery chemistries, specifically Lithium with Lead Acid batteries, the DC to DC charging converter is definitely the way to go as each battery gets what it needs. Connect your engine battery to the input side of the DC to DC charging converter and the output is the Lithium battery.