Charging 12 volt batteries wired in parallel requires a 12 volt battery charger. Two batteries in parallel one charger batteries connected in series strings can also be recharged by a single charger having the same nominal charging voltage output as the nominal battery pack voltage.
2cf1a Solar Battery Parallel Wiring Diagram Wiring Library
Charging 2 12v batteries in parallel. But what happens if you wire batteries of different voltages and amp hour capacities together in parallel. Change the switch to 1 or 2 and use each battery by itself. Two 12 volt batteries in parallel one 12 volt charger figure 9. This link is and example of what type of switch i am talking about. Put the switch in 12 and now they are in parallel. Two 6 volt 45 ah batteries wired in parallel are capable of providing 6 volt 9 amp hours 45 ah 45 ah.
Connect the dual charger to each battery put the switch in off and let them charge. If the charger is then removed and the batteries are left in parallel the charge will equalize but now neither battery will be fully charged. An example method of charging batteries in parallel is to use one branch of the parallel circuit to charge each battery with a single charger. In figure 8 a single 24 volt charger is connected to a 24 volt battery pack. Connect the positive output of the charger to the positive terminal of the first battery and connect that positive terminal to the positive terminal of the second battery. Multiply the time anticipated to charge one battery by the total number of batteries.
For example if charging one battery normally takes three hours and you have five batteries linked in parallel the charging time will be five times three hours or 15 hours. The problem is that batteries are never quite identical so in parallel one battery will always charge better than the other causing the charger to think that both are fully charged when only one is. The process is simple but as the capacity of the batteries increases depending on the number of batteries wired in parallel it can take twice the time to charge two 12 volt batteries and three times as long for three batteries. Four 12 volt 2000 mah wired in parallel can provide 12 volt 8000 mah 2000 mah x 4.