How to Add a Second Battery to a Car for Car Audio Installation

If you’re looking to upgrade your car audio system, adding a second battery may be necessary to handle the increased power demands. In this guide, we’ll show you the best way to wire a secondary battery and the best configuration for fitting it in your trunk.

Firstly, it’s important to note that this guide is based on a Nissan Versa, but the principles can be applied to any car. The team at Provo Beast created a board specifically for the Nissan Versa that allows them to mount multiple components, including the secondary battery, amplifier, miscellaneous wires, and a couple of fuses.

To begin, they connected the main line from the front battery – a blue wire that’s hooked up to the alternator – to the positive terminal on the secondary battery in the trunk. They also recommend fusing the wire as close to each battery as possible for safety reasons.

Next, they connected the amplifier to the positive terminal of the secondary battery, again using a fuse in case there’s a short circuit. The ground for both the battery and amplifier were connected to the chassis, with the team using a seat belt bolt to ensure a clean connection.

It’s worth noting that they also removed the seat belt bracket to access the threading, which is one of the best places to ground an amplifier or battery.

Once everything was connected, they used the homemade board to mount the secondary battery, amplifier, and other components. They also chose a five-channel amplifier but left room for more if needed.

If you’re planning on adding a second battery to your car, make sure to follow these steps for a safe and reliable installation.