How Do I Figure Out What Size Battery Charger I Need for My 1,320 Ah Battery Bank? Do I Need Two?

Question:

I have a 61’ boat with 12 house batteries. They are charged via a 60A charger but it takes forever to charge the batteries. If I wanted to add another charger do I have to separate my battery bank?

Answer:

Your hunch is right, sizing a battery charger to a battery bank is important to maximize battery life.  Let’s assume that the 12 house batteries are flooded golf cart batteries. That would translate into 1320 Ah battery bank. A flooded battery bank of that size should have a charge rate of least 10% of battery capacity, i.e. 132A charger. Getting a charge rate of 15% of battery capacity would be better. I would suggest to install a second high output charger to meet the right charge rate.