After a lot of testing and tweaking, I’m finally happy with how my Lithium iron phosphate or LiFePO4 batteries are charging using my narrowboats alternator. Initially, the charge was too harsh so I used a Victron BMS 12/200 to regulate the current and give me the option to disable the charge when I want to.

Victron BMS 12/200

Victron Alternator Control Cable

Marine Grade Battery Box

Blue Sea 300A Switches

Victron BMV 712 Battery Monitor

Blue Sea MaxiBus Insulating Cover 2719