Any experience with dual battery setups?

Hey guys just wondering if anyone out there has dual batteries in their cj5. I was putting on the new soft top last night and got to thinking of some minor mods I might do in the future. I did see a 1979 CJ5 on the net that had a dual bettery tray installed and it is listed on quadratec's websight as being for a 1970 or newer jeep. Anyone know the difference in inner fender to firewall distance difference between my 1966 and a 1970 CJ5?

http://www.manoian.net/jeep/dual_batteries.html

The websight above is the one that has the article. I already have a AC Delco 160 Amp alternator under the hood so I have plenty of juice available. I was thinking of installing a winch sometime in the future too. Any thoughts would be appreciated.

 

I don't think it is worth the effort. You can do alot of winching with 1 battery. Seems one battery is always bad and needing replacing in a duel setup.

JB

 

I tend to agree with the single battery set-up. The key is a large capacity battery- Lots of CCA's (cold cranking amps) :JEEP:

Mark

 

I have been looking at dual battery setups too. I actually ordered that Tomken dual battery tray from Quadratec, it WILL NOT fit on our Jeeps. There just isn't enough room between the fender and the firewall for 2 batteries. I had my friend who works in a machine shop, make me a custom battery tray that I am going to mount on the other side of my firewall behind the glovebox door in all the open space on my Jeep. I think it's going to be pretty trick. Besides, 2 batteries has got to be better than one.

 

Please post pics of your install.. Just 'cause I prefer a single bat. doesn't mean it's not an interesting discussion.
M

 

I would like to see that too. I am constantly trying to find a little extra room in the jeep for such things...

 

This brings up something I've been wondering about...

On the M38's and M38A1's with 24v systems, are they dual 12v batteries in parallel or one 24v battery?

 

Dual 12v batteries in SERIES. Parallel would make them still be 12v.

 

You guys got it. I will take some pics tonight and get them up. I am really excited to see how this comes out.

 

Yeah, you're right, series...not parallel. My bad. I've done four 12v's in series to get 48v in telecom applications, but it's been a few years.

But is that how the military Jeeps originally were, with two 12v batteries and not one 24v? Just curious.

 

Yes, two 12v batteries and not one 24v one. Military vehicles are still like that today.

 

Schweet! Dass what I wanted to hear! If I score that M38, I didn't want to have to buy some special obsolete 24v battery for it. Thank you sir.

 

I ran dual batterys on an '87 chevy with an 8274 warn that i'm going to put on my 715. My '59cj also has an 8274 with a single batt. Two batterys are definetly better than one but they do have a couple of drawbacks. If you do'nt run an isolator you can draw down both batts. intead of just one. Also the weaker of the two will draw off the stronger one. This usually goes unnoticed, only talking about a small amount of juice. This is why both batterys must be good and of the same condition. I've had friends that have burned isolators up, thats why i never had one. I also never had problems keeping them both charged up. Not a problem until they start to get old. BTW the truck i drive it work has four batterys and a 100 amp alt.

 

Well, I know it's been a little while since we talked about this but I finished up the dual battery install last night. (Just need to clean up some wiring and put the loom around it all) It came out really clean and I am excited because you guys know stuff never turns out how you planned it on these old CJ's. I was able to get the second battery mounted behind the glovebox door on the backside of the firewall. I drilled a hole in firewall for the cables and wiring to go through and mounted the painless isolator on the passenger fender. I know, I know, UWOP. My wife has the digital in Calif. but I will take some pics tomorrow when she gets back.

Mike