In consideration of your auxiliary power needs you may choose to install an auxiliary battery system. Selection on the battery for this system is critical to the performance and reliability. I chose to use an Odyssey battery to power my system. For me I needed a battery that met the following criteria:

• True Deep Cycle
• Ability to run ARB Fridge through the night
• Provide power for other accessories while the FJ is not running
• Small foot print to fit on the right fender of the FJ
• Reliability and quality
• Can be used to jump start the FJ if the primary battery is dead

The Odyssey battery ingeniously uses absorbed glass mat (AGM) technology to offer, in one box, the characteristics of two separate batteries. It can deep cycle as well as provide enormous cranking power. The Odyssey uses high quality pure lead plates and is completely sealed and can be shipped via USPS or UPS. The battery can be mounted in any position but upside-down so it is very versatile. The Optima batteries utilize a round cell which is not nearly as efficient use of space.

I selected the
PC925
battery which provides 28 AH which works fine to keep the fridge running all night.

This battery weighs 26 pounds and should not stress the fender that much.

The battery has female brass studs which works well for accessory wiring systems.

The price for this battery is: $153.54

For you system Odyssey has a LARGE number of battery sizes to fit many applications.

If you want to replace your primary FJ Cruiser battery with the best battery on the market I recommend the Odyssey
PC2150/31T. This battery is a little longer than the factory FJ battery but will fit with some modification to the battery tray.