Dual battery set up

[SavageSun4x4]

I am looking for plans/part numbers/components needed to do a dual battery setup for my Jeep.

On that same note I will have 3 batteries in play.

1) Starter battery for engine and Jeep only extras at the fuze box

2) Winch and external jumper cables

3) Battery in my trailer for powering lights and other electrical requirements while camping. I would like to be able to charge this battery while driving. When the battery is not being charged by the Jeep/trailer not attached I will use a solar trickle charger to maintain the battery.

For you smart guys, I would like to get your recommendations on regular or deep cycle. I currently have on hand 1 Optima red top that is several years old. I am thinking of using it for my starter battery till it dies.

I also would like to have the ability to start off another battery, but this is not mandatory.

Plans are for the batteries to be installed separate from each other. 1 in the fender well where it is located now and one behind the seats (note: this will be the starter battery, the one in the fender well is for the winch). Thanks for the help.

Note: I have looked around and finding info is easy, sadly some of the info appears to conter other info. You will be happy to note that this is one of the few boards I even trust to give me a legit and honest, smart answer.

[Jerry Bransford]

There's some good information on a dual battery setup at http://www.jeepforum.com/forum/showthread.php?t=493384

For charging your trailer's battery while you tow, just run an 8 or 10 gauge wire from the Jeep's + battery lead back to the trailer battery. An easy point to attach it at your TJ's battery is at the front of the PDC (power distribution center) where it gets power from the battery. Just make sure to disconnect it when you're parked as one or the other battery could slowly drain the other since the batteries won't be identical. Also, you can run this charge lead through the 7 pin trailer connector if that's what you're using, one of the connector pins is actually designated as the charge wire connector.

A combination deep cycle/starting battery is ideal for the winch. Good choices for that would be the Sears Diehard Platinum, Odyssey PC-1200 or PC-1500, Optima D34M Blue Top, or Optima Yellow top... in that order though the Diehard Platinum is just a rebadged Odyssey battery, and the Blue and Yellow Top batteries are identical internally with just different external connectors. Use the Red Top as a starting battery until it dies.

A few things to keep in mind... running batteries in parallel with nothing to keep them isolated electrically is asking for trouble as dissimilar batteries don't do well when connected to each other. Even two otherwise identical batteries but different ages can cause problems for each other if connected in parallel without an isolator between them.

Charging two batteries simultaneously can be done with a charge isolator (one in-connector, two out-connectors) which is available at nearly any large RV or boating supply store. If you go for an isolator to allow two batteries to be charged at once, make sure it is rated for more amps than your charger is rated for which is 117 amps.

Mean Green has a pretty cool dual-battery setup but be sure to check out what Kodiak Industries at http://www.kodiakinc.com/dual_battery.html has. They also specialize in Odyssey batteries and their dual battery kit is designed around them.

Hope that helps, I'll go for a dual battery setup one of these years after I get all my other higher-level TJ needs taken care of.

[SavageSun4x4]

Thanks Jerry, knew I could get some straight answers on here

[Lawrence]

Don,

To add to Jerry’s comments, I would choose the Sears Platinum line. They are rebadged Odyssey batteries, they have an excellent warranty, and should you need a replacement on the road, there is a Sears in just about every major city for convenience.

The “regular” Platinum has a 4 years free replacement and up to 100 months prorated, and the deep cycle version cuts the free replacement to 3 years. I was told the reason is that they expect people to put those in boats and RVs, and that they’ll therefore be subject to sitting still for longer periods of time.

I have the Group 34 P1, and I have been happy with it so far. Erik is also running it, and Dan just bought the P4 version with the side posts.

I also agree with Jerry on the isolators to keep you out of trouble and being able to charge both batteries. On my old YJ, I had a kit similar to the Kodiak and it stopped working within a year. I wasn’t too impressed with it, and if I were to do a dual setup, I would look into RV or marine isolators instead.

For the trailer battery, I am not sure what your power and weight requirements are, but if you plan on drawing a lot, look into a pair of 6V ones, and the best one I have found is the Lifeline GPL-4CT. I would also use an isolator so you can leave your trailer hooked up overnight without running the risk of discharging the TJ batteries.

If you don’t have a trailer harness yet, look into the Mopar one for the 2004 Unlimited. That’s the one I bought, not the cheapest, but a very nice plug and play harness (no splicing). It comes with everything you need, it has the 7RV plug allowing you to charge your trailer battery while running, and it has a built-in brake controller wire in case you want to use one.

[SavageSun4x4]

THANKS Law-man.

Yes, I am hearing a lot of good stuff on the Sears Plat bat. I stopped down at Sears the other day and they were almost sold out of them, no kidding they only had 2 on the rack in the store.

I think I will go with a Sears deep cycle in the trailer and in the fenderwell, the starter will go in the tub with me.

Trailer set up, bottom 6 pics: http://www.savagesun4x4.com/enter/je...trailer_2.html