# What Gauge Wire to Connect Two 12V Batteries in Parallel?

by Phil Borges // in Car

Connecting two 12V batteries in parallel is a common practice in dual battery systems. When connecting the batteries, it’s important to use the right size of wire to ensure that the system runs efficiently and safely.

## What Size Cable Should I Use for a Dual Battery System?

The size of cable you need for a dual battery system depends on the amperage of the system. A good rule of thumb is to use a cable that has a cross-sectional area of at least 20% greater than the largest wire in the system. For example, if the largest wire in the system is 10 AWG, you should use a cable that has a cross-sectional area of at least 8.4mmÂ².

## What Gauge Wire Should Be Used with 12-Volt Battery?

When selecting a wire gauge for a 12-volt battery, it’s important to consider the amperage of the system. As a general rule, a 16-gauge wire can handle up to 10 amps, a 14-gauge wire can handle up to 15 amps, and a 12-gauge wire can handle up to 20 amps. However, if you’re running a high-amperage system, you may need to use a larger wire gauge.

## What Size of Battery Cable Do I Need?

The size of battery cable you need depends on the amperage of the system. As a general rule, a 2 AWG cable can handle up to 175 amps, a 4 AWG cable can handle up to 125 amps, and a 6 AWG cable can handle up to 80 amps. However, if you’re running a high-amperage system, you may need to use a larger cable size.

## How Do You Wire Two 12-Volt Batteries in Parallel?

Wiring two 12-volt batteries in parallel involves connecting the positive terminals of the batteries together and the negative terminals of the batteries together. This creates a single 12-volt battery with twice the capacity of a single battery. It’s important to use the same type and size of battery when wiring in parallel, and to use the correct size of wire and cable to ensure that the system runs efficiently and safely.

## Conclusion

Connecting two 12V batteries in parallel is a common practice in dual battery systems, and selecting the right size of wire and cable is crucial for the system to run efficiently and safely. The size of cable and battery cable required for a dual battery system depends on the amperage of the system, and a general rule of thumb is to use a cable that has a cross-sectional area of at least 20% greater than the largest wire in the system.

It’s also important to use the same type and size of battery when wiring in parallel and connect the positive and negative terminals correctly. By following these guidelines, you can ensure that your dual battery system operates safely and effectively.

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.