Selection of Chargers is Dictated by Hookup Wiring
RV Parks usually have 3 different sizes of plug-ins to use. Each different plug is designed to carry varying sizes of amperage safely, and is different so you don't plug into the wrong one inadvertently. Simply put, 120 volts AC current, at the proper hertz, is supplied in;
Up to 15 amp circuits using a regular Edison plug.
Up to 35 amp circuits using a modified Edison Plug.
Up to 50 amp circuits using a 125 volt Edison Plug.
Each of these varying amperages can drive varying numbers of battery chargers at varying amperage charging rates. To see the math to show you the maximum charger amps that could be powered by any of these circuits It would take 5 x 40 amp chargers to fully load a 15 amp circuit at 12 volts. However, at 48 volts, only 2 x 40 amp chargers would blow the circuit breakers, and quickly.
Assuming 12 volt charging;
15 amps x 110 volts = 1660 watts = 12 volts @ 183 amps
(4 x 40 amp chargers would be just fine at 12 volts)
35 amps x 110 volts = 3850 watts = 12 volts @ 320 amps
50 amps x 110 volts = 5500 watts = 12 volts @ 458 amps
Assuming 48 volt charging;
20 amps x 110 volts = 2200 watts = 48 volts @ 45 amps
35 amps x 110 volts = 3850 watts = 48 volts @ 80 amps
(2 x 40 amp chargers are too much at 48 volts)
50 amps x 110 volts = 5500 watts = 48 volts @ 115 amps
Assuming that the overnight charge for power varies by hookup amperage, you should select the smallest size you deal with. The smaller the amperage, the fewer, or smaller the charger(s) you can run. Selection of your charger is therefore a give and take situation, you should optimize for your situation.
For most 12 volt systems a good rule of thumb is the small, normal, 20 amp, Edison plug.
You can get a heavy duty extension cord at the local hardware store, not get the wires hot, and charge the batteries with up to 4 chargers at a time.
For 24, 36, and 48 volt systems, the size of the chargers selected usually dictates the size, number, and configuration of AC connections used for safety reasons. This site encourages you to seek professional help with these installations. We are happy to send you the parts, and your local RV shop is usually very happy to install them. Just ask!