Auxiliary Battery selection

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.

Odyssey Batteries vs. Spiral Wound

I selected the
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.



Tomas has lived in Colorado since age 5. Having grown up on the Western Slope of Colorado lots of time was spent in the Desert Southwest. Tomas' father introduced him to the love of 4 wheeling at an early age in the high mountains around Aspen, Colorado. While an avid Mountain Biker, Tomas and his Family enjoy adventures in the mountains and desert in the remote locations that can only be reached by 4wd. Day hikes are always a must when on the family trips. While enjoying outdoor activities he wants to share his love as a certified 4wd trainer and ski instructor. Tomas also enjoys caving and cave exploration. Tomas currently resides in Colorado Springs. 


  1 comment for “Auxiliary Battery selection

  1. Taylor H
    February 7, 2011 at 11:25 AM

    This battery is Good but not the best, you should look into the Rock racing from lifeline battery the technology put into the rock racing is the same as the technology as the batteries put in too Military Aircraft (ex. F-18 hornet , F-117 nighthalk , ETC.) TRUST ME if you want the best battery you can get the Lifeline Rock racing from Air craft battery corp Concorde Battery Hand Made in the USA.

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