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Wiring Your Battery Bank In Series Parallel

The Basics of Wiring Up Your Battery Bank in Series 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 solar applications run off a 24V DC type of system. In order to build up your battery voltage and capacity, you will need more than one battery in order to attain the storage and voltage that you need. Also, you may run into space or cost issues with the larger 12v batteries. Often people will use two 6 Volt batteries wired in series parallel to get to the 12 volts and 500Ah that they need.

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.

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Wiring Your Batteries In Series | Wiring Your Batteries In Parallel

What Does Wiring Your Batteries in Series Parallel Mean?

When you wire batteries together in series parallel you will increase the voltage and amperage by the number of batteries in the group. For instance, below the two 6V 250Ah batteries pictured there, if wired in series parallel will give you a total of 12V at 500Ah. You can see several other example of what a 12V 500Ah, 24V 1000Ah, 36V 1500Ah and 48V 2000Ah battery bank in series parallel looks like.

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

How Many Batteries Do I Need?

(Total Volts Needed) / (Volts of Single Series) = Number of Batteries Needed
(Total Amps Needed) / (Amps of Single Battery) = Number of Batteries Needed
(Total Batteries for Amps) / (Batteries Needed for Total Volts) = Number of Strings

example.. 24V (needed) / 6V (per battery) = 4 (batteries needed per series)
example.. 2000Ah (needed) / 250Ah (amps per battery) = 8 (batteries needed total)
example.. 8 (batteries for amps) / 4 (batteries for volts) = 2 (series strings of 4 batteries)

The total batteries for each equation should match or you will need to increase the voltage of the batteries that you are using or the amperage of the batteries that you are using. This may not always be an easy task depending if you have size requirements or restrictions.

What Will My Total Voltage & Amperage Be?

(Total Batteries Per Series) x (Volts of Single Battery) = Total Volts
(Total Amps of Series) x (Number of Series Strings) = Total Amps

example.. 4 (batteries per series) x 6V (per battery) = 24V (total voltage)
example.. 1000 (batteries total) x 2 (series strings) = 2000Ah (total amperage)

The total batteries and amperage should match your needs or you will need to increase the voltage of the batteries that you are using or the amperage of the batteries that you are using. This may not always be an easy task depending if you have size requirements or restrictions.

Wiring Batteries In 12V Series Parallel Configuration

The following wiring configuration requires four 6V batteries. Using any four 6V batteries group them in two groups of two.Wire each group positive to negative will give you 12V on the furthest negative and positive post not wired to another battery. Then with the two groups wire the two groups together positive to positive and negatives to negative to give you 500Ah.

Diagram showing batteries wired in 12V 500Ah series parallel configuration

Wiring Batteries In 24V Series Parallel Configuration

The following wiring configuration requires eight 6V batteries. Using any eight 6V batteries group them into two groups of four. Wire each group positive to negative will give you 24V on the furthest negative and positive post not wired to another battery. Then with the two groups, wire them together positive to positive and negatives to negative to give you 1000Ah.

Diagram showing batteries wired in 24V 1000Ah series parallel configuration

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. Then with the two groups wire the two groups together positive to positive and negatives to negative to give you 1500Ah.

Diagram showing batteries wired in 36V 1500Ah series parallel configuration

Wiring Batteries In 48V Series Parallel Configuration

The following wiring configuration requires (16) 6V batteries. Using any (16) 6V batteries group them in two groups of eight. Wire each group positive to negative will give you 48V on the furthest negative and positive post not wired to another battery. Then with the two groups wire the two groups together positive to positive and negatives to negative to give you 2000Ah.

Diagram showing batteries wired in 48V 2000Ah series parallel configuration