Frequently Asked Questions


Q:  Which batteries do you recommend for your systems?

A:  For the “side-by-side” battery systems, it is important to take weight into consideration.  For these systems, we recommend Odyssey PC1400 Group 35, Optima D35 YellowTop or Diehard Advanced Gold Group 35.

For the “split systems” (batteries are separated on either side of the engine compartment), we recommend higher capacity AGM batteries.  The Odyssey PC1400 Group 35 works very well, as does Northstar Group 35, X2 Power Group 35, Optima D35, and Diehard Advanced Gold Group 35.


Q:  What is the largest battery I can fit in the passenger side trays?

A:  All OGE trays so far have been designed to hold a Group 35 AGM battery.  A Group 34 will fit if you’re willing to “massage” your AC lines out of the way on your 2nd Gen Tacoma.  34’s fit just fine on the 3rd Gen Tacomas, but the tiedown will not be centered.  Group 35 AGM batteries are also recommended for the 4Runner and GX trays and systems.

Q:  What is the largest battery that will fit in the driver’s side trays?

A:  Whatever the largest stock battery you can fit is.  Anything larger than a Group 35 will hang off the edges, but will remain plenty secure.


Q:  I just bought a new fancy battery or; I have a new truck and don’t want to replace the battery yet. Can I keep my current battery and add another for a dual battery setup?

A:  Yes, with certain restrictions.  Ask any expert and they’ll tell you: It is always recommended that ALL batteries in a “bank” or battery system be of the same size, age, and construction type.  This has to do with the difference in charging rates amongst battery types and sizes.  With different batteries in the same bank, one of them is bound to be over or under charged, thus drastically reducing its life.  In a perfect situation, one would purchase two brand new, identical batteries for a dual battery system.

Q:  But, I really don’t want to buy two new batteries.  Are you sure I can’t get away with running different batteries? Pretty please?

A:  Sure. Plenty of people do it and get away with it.  If you’re going to do it, the most important rule to abide by is making sure the construction type of the batteries is the same.  If your old battery is a traditional flooded cell, then make sure your second battery is the same.  If your old battery is an AGM, then make sure your new battery is the same.  The second most important is size.  Try and match them up as close as possible.

Off-Grid Engineering LLC is a limited liability company. Our products are designed for off-road use only and have not been tested for collision scenarios. We can not be held liable for faulty installation of products or damage to vehicles caused by the faulty use or damage of our products. Please do not modify any of our wiring or cable kits. We always recommend circuit protection/ fusible links for aftermarket wiring.