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Wiring Your Battery Bank In Parallel

The Basics of Wiring Up Your Battery Bank in Parallel

There are many ways to wire batteries to attain the kind of bank that you need to suit your needs. For instance, commonly RV's and Marine applications run off a 12v DC type of system. In order to build up your battery capacity, you will probably need more than one battery in order to attain the storage that you need. Typically running batteries in parallel is when you need more storage storage space than voltage. Often people will use two 12 volt batteries wired in parallel to get to the higher amperage that they need. In my example I'm using 6V batteries for the demonstation but generally it would be 12V batteries.

Good battery interconnect cables are an essential part of putting your battery bank together. Choosing the proper gauge wire is critical and the correct wire length determines the efficiency of your system. Cables that are too long will result in power loss and unnecessary resistance. We currently offer 1/0 AWG, 2/0 AWG, and 4/0 AWG battery interconnect cables.

Our other battery wiring guides and examples
Wiring Your Batteries In Series | Wiring Your Batteries In Series-Parallel

What Does Wiring Your Batteries in Parallel Mean?

When you wire batteries together in parallel you will increase the amperage by the number of batteries in the group. This is done while keeping the volts the same. For instance, below the two 6V 150Ah batteries pictured there, if wired in parallel will give you a total of 6V at 500Ah. You can see several other example of what a two 6V, four 6v, six 6v and eight 6v battery bank in parallel looks like.

The equations are simple for parallel configuration. There are two basics ones below.

How Many Batteries Do I Need?

Use If you know the battery amperage that you are using.

(Total Amps Needed) / (Amps of Single Battery ) = Number Of Batteries Needed

example.. 2000Ah (needed) / 250Ah (per battery) = 8 (batteries needed total)

What Will My Total Amperage Be?

Use If you know the total batteries and single battery.

(Total Number Of Batteries) x (Amps of Single Battery ) = Total Amps of Parallel Config

example.. 8 (batteries total) x 250Ah (per battery) = 2000Ah (total amperage)

Wiring Two Batteries In Parallel Configuration

The following wiring configuration requires two 6V batteries. Using any two 6V batteries wiring all positives to each other and all negatives to each other will give you 500Ah rating on the furthest negative and positive post not wired to another battery. This is the point where you will connect your load.

Diagram showing batteries wired in 500Ah parallel configuration

Wiring Four Batteries In Parallel Configuration

The following wiring configuration requires four 6V batteries. Using any four 6V batteries wiring all positives to each other and all negatives to each other will give you 1000Ah rating on the furthest negative and positive post not wired to another battery. This is the point where you will connect your load.

Diagram showing batteries wired in 1000Ah parallel configuration

Wiring Six Batteries In Parallel Configuration

The following wiring configuration requires six 6V batteries. Using any six 6V batteries wiring all positives to each other and all negatives to each other will give you 1500Ah rating on the furthest negative and positive post not wired to another battery. This is the point where you will connect your load.

Diagram showing batteries wired in 1500Ah parallel configuration

Wiring Eight Batteries In Parallel Configuration

The following wiring configuration requires eight 6V batteries. Using any eight 6V batteries wiring all positives to each other and all negatives to each other will give you 2000Ah rating on the furthest negative and positive post not wired to another battery. This is the point where you will connect your load.

Diagram showing batteries wired in 2000Ah parallel configuration