On my catamaran I have 990 watts(36v) of solar and a Smartsolar mppt 150/100 tr powering my x5 170Ah AGM batteries @12v. Occasionally we have rain for days on end and require a top up. I have a 110v gas powered generator/invertor (2300/1800watts) and a Shumacker 12v speed charge 2/10/30amps that came with the boat. Before I hook up the charger direct to the batteries and fire it up I thought I'd look for recommendations or concerns?
Will it work? Yes, provided the charger can hit the proper target voltages for AGM batteries.
5X 170Ah batteries would prefer 85A of charging. Low current bulk charging below 0.1C encourages sulfation.
Assuming proper charge voltage, 30A * 14V = 420W = a small fraction of your generator's output and definitely in a less efficient operating range, i.e., you'll burn more gas per kWh charged.
Recommend you get a higher power charger (85-100A) that will charge the batteries at a more favorable current in a more efficient power range for your generator.
If you have a BMV or other shunt, make sure the charger is attached to the non-battery side of the shunt to ensure the battery monitor can see the input current.
