AGM 4d Charging Requirements

[Fiftybucks]

I need to replacing (2) 4d AGMs 200AH house batteries. In reading the specs on the batteries it shows minimum charging amperage at 40 amps. I have a plugin smart maintainer at 4 amps for use at the slip. Could I go with Dual Purpose or stay with specifically Deep Cycle.

[smac999]

4a is way to small for any boat.

Your fridge probably draws 4a. So plugged in you won’t even charge the batteries.

EVen if you change to flooded you’d still want 10% charger or 40a. The agms Likly want 40a each = 80a charger.

An 80-100a charger is normal on any 35-45’ boat around here.