MinnKota MK 210D On-Board Battery Charger

You can get this in a 5 amp per bank or 10 amp per bank.  The more amps the faster it will charge your batteries.  If you are ever camping and want to charge your batteries overnight I would recommend 10 amps.  You will need one bank per battery you have in your boat.   Brand: Minn Kota Color: Black Features: Part Number: 1822105 Oem Equivalent Part Number: 702089 Fit Type: Universal Fit 2 banks; 5 amps per bank Multi-stage charging and automatic temperature compensation Saltwater tested and fully corrosion-resistant Three-year warranty Digitally controlled microprocessor design protects your batteries so you can stay on the water longer