The easy (and proper?) way to charge a 48 volt battery bank is to use a 48 volt charger. If you only have a 12 volt charger, you can charge the individual 12 volt batteries one-at-a-time without rewiring anything - your charger's negative terminal should not be connected to "Ground".
Some Final Words. Tip #1: If you use a 12-volt charger for one battery, make sure to keep your eye on both. This is not the best way to recharge 8-volt batteries. Tip #2: if you have 3 batteries to charge, take 2 12 volt battery chargers and hook the batteries up in a series.
2. Always Inspect Terminal Clamps and Cables. Proper charging involves connecting the positive terminal (red) to the positive battery pole, then connecting the negative terminal (black) to the negative terminal on the battery. Simply connecting these terminals will not charge your vehicle’s battery.
Then connect the black cable to the negative terminal of the car battery. Now, plug your charger into the wall or extension cord that’s plugged into the wall. When the charging process is complete, unplug the charger. Wait 10 seconds for any residual power to dissipate, and remove the black cable first. Remove the red cable. 2-Amp Charger: A battery charger with low amp charging, such as 2 amps, can recharge a battery in one to two days. This is because a 2-amp battery provides only 1 ampere per hour. 4-Amp Charger: Generally, a car battery holds 48 amps, so using this amount of voltage will take up to twelve hours to reach full battery capacity. Sizing Your Solar Panels. Continuing with our example of a 300Ah 12v battery (with a 3600Wh capacity) and an expected daily discharge of 2780Wh, we can determine what size solar panels we need to both keep our appliances operating and fully charge our battery banks. To operate these devices alone, you will need 2780Wh of power. .charging a battery with a charger
