Aux Battery

**98BURB** · 03-13-2007, 05:57 PM

First let me say hello. Lots of great info here. I now know that my 98 is not evil it's justa burb.

Anyways,want to add an aux battery to the truck. It has an extra tray and the current battery appears to be hooked up to some kind of power box supply over the left fender. Can I just run a new+ lead from that box to an additional battery. If so where do I ground the new battery. Thanks for any info.

**Steve** · 03-13-2007, 06:07 PM

Welcome to the site!

Running multiple batteries together is pretty common. I forget, but one of the guys should know how to do it.

**TrailLeadr** · 03-13-2007, 06:37 PM

You can either run the batteries together in parallel (pos to pos; neg to neg) Or splice off, and run a second pos line to the second battery, then ground the new battery to any chassis location.

**Cableguy** · 03-13-2007, 07:53 PM

Originally Posted by TrailLeadr

You can either run the batteries together in parallel (pos to pos; neg to neg) Or splice off, and run a second pos line to the second battery, then ground the new battery to any chassis location.

yepper spot on, positive to positive would give you 12vdc with double the load capacity. Plus altenator will float charge both batts. May we ask why you need this?

**unplugged** · 03-13-2007, 08:36 PM

I like to run the second battery as a backup that is disconnected from the primary battery except when the engine is running. That way when I'm on location playing the stereo, or running other accessories, the backup battery is ready to crank 'er up even when the primary battery is dead.
Here is a diagram from http://www.hellroaring.com/simple.php

**TrailLeadr** · 03-13-2007, 08:44 PM

Very nice simplified diagram!

**GWAGON_99** · 03-13-2007, 10:22 PM

I would follow the diagram. I looked into it myself and found that it is best to have a cut off switch. That way if something drains one battery you just switch to the other one and your on your way. Especially since its not to dificult and fairly inexpensive. I was going to go with my current Red Top Optima and add an aditional Deep Cell Yellow top to help with the winch I am trying to convince my wife to let me buy!

**collinsperformance** · 03-13-2007, 11:59 PM

i made a second battery tray and was going to a boat shop or battery shop and they got a great switch one or the other or both batteries. just swap the dial when playing and you will have one as a backup they sell new for $15
mike

**98BURB** · 03-15-2007, 12:55 AM

Thanks, I just thought it would be nice to have a backup. The kids leave the reading lamps on alot. And i use an a/c converter alot for equipment charging and have drained the battery a few times. Thanks again

**fierodough** · 03-15-2007, 05:46 AM

Is it not bad to have the batterys in straigh parallel? I hear that it's either rough on the alt or on battery is constantly charging the other. I dunno, something like that... I'm looking in to this too, but I don't want to kill the alt. or have 2 fried batterys.

WIth 2 batterys, you would have a hard time running them down unless you were running a pretty big load without the engine running. Besides, the 'Burb comes with 2 batterery tray stock, with that second tray empty, it looks like something is missing.

Cheers!