John brings up a good point. Equalization in charging multiple batteries is an important issue to address. If your battery bank is as simple as mine, a smart charger works well. 12V flooded batteries in parallel like to be charged as one big battery. With the proper charger connections, charging them as one benefits all of the batteries (assuming all batteries are of the same brand, age, and group). Has worked well many years for me boondocking during the camping season (No available AC power other than generator).