Battery Bank Wiring Diagrams

Below is a collection of quick reference diagrams on hooking up multiple 6 volt and 12 volt batteries to create 6V, 12V, 24V, 48V etc as required for energy storage systems commonly found in residential and off grid solar, hydro and wind systems.

John I have an electric bike that has 3 12 volt 7 amp batteries and range is an issue. I want to buy 3 12 volt 12 amp batteries for a total of 6 in all, hook them up parallel to keep my 36 volt current. my goal is to extend the range of the motor and bike. Can I use to the two sets of battery‘s together or should I mix them or what?

If you wire two 200ah 6 volt batteries together in series you end up with 12 volts but the amp hours remain 200. The good news is you can combine series and parallel wiring with 6 volt batteries so you can combine 4 or more and keep the voltage at 12 for your RV but increase the amp hours. I’ll go through each of these wiring methods below.

Chances are, your motorhome has a 12 volt system, in which case you would wire the two batteries in parallel (assuming the batteries are 12 volt). This would provide 12 volts of output. You can see this by looking at the diagram I provided. If you want the battery voltage to double, like using two 12 volt batteries to power a 24 volt system ...

The same thing happens when you wire two 12-volt batteries in series to power a 24-volt trolling motor. You connect the negative wire from the trolling motor to the negative terminal of one battery.

This diagram shows a simple parallel circuit to increase current or power. Assume that we are using 12 volt batteries. The power of all 3 batteries add to give us the effect of a battery 3 times as powerful but the voltage stays the same at 12 volts. Parallel wiring increases current but the voltage does not change.

Wiring Batteries In 36V Series Parallel Configuration. The following wiring configuration requires (12) 6V batteries. Using any (12) 6V batteries group them in two groups of six. Wire each group positive to negative will give you 36V on the furthest negative and positive post not wired to another battery.

Unlike wiring batteries in series when batteries are wired in parallel the voltage does not increase, the output voltage is the average voltage of all batteries in the circuit. For example if a 3V and a 9V battery were wired in parallel the output voltage would be 6V ( 9+3 divided by 2 ) however the current will be total amperage of all batteries in the circuit (minus any losses).

Once you have the batteries wired properly in parallel you will need to connect the 12 volt power wire from the trailer 7-Way connector to the positive wire on the first battery. This connection will help maintain the batteries when the vehicle is running, but will not charge them sufficiently from a discharged state.

two 6 volt 4.5 Ah batteries wired in parallel are capable of providing 6 volt 9 amp hours (4.5 Ah + 4.5 Ah). four 1.2 volt 2,000 mAh wired in parallel can provide 1.2 volt 8,000 mAh (2,000 mAh x 4). But what happens if you wire batteries of different voltages and amp hour capacities together in parallel?