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View Full Version : Which dual battery system to use?



Cue-Ball
11-11-2004, 08:20 PM
Hey there all I wonder what dual battery set ups anyone here has used or knows anything about?

I am going to be running dual Optima Yellow tops, but I need to find out the best way to wire them all up and all.

I have heard Painless's is not the way to go but what about Hellroaring, or Wrangler NW.

Does anyone have any advice?

OverkillZJ
11-12-2004, 01:04 AM
I cooked my painless setup.


Make your own. One solenoid and a switch. Not hard.

Kraqa
11-12-2004, 01:30 AM
I cooked my painless setup.


Make your own. One solenoid and a switch. Not hard.


werdhttp://img.photobucket.com/albums/v280/Kraqa/thefinger.gif

Alaska ZJ
11-12-2004, 01:46 AM
No selenoids and no switches. Even better.

OverkillZJ
11-12-2004, 02:13 AM
No selenoids and no switches. Even better.

Parallel? No thanks, I have my solenoid in there for a reason!

Backup battery in my case. I've had to jump it from myself when I do something stupid like leave the headlights on all night.

Cue-Ball
11-12-2004, 11:03 AM
Do you have any specs on the solenoid and switch you have used?

OverkillZJ
11-12-2004, 04:33 PM
Do you have any specs on the solenoid and switch you have used?

solenoids just some cheapy I found at allelectronics.com rated for 200 amps, and a 3 way switch. Switch only needs to handle a coupla amps.

Cue-Ball
11-12-2004, 04:51 PM
So would this one work?
http://www.allelectronics.com/cgi-bin/category.cgi?category=575&item=SOL-80&type=store

What are these other kit charging like $150+ bucks for if it is just a cheap part?

OverkillZJ
11-12-2004, 06:23 PM
So would this one work?
http://www.allelectronics.com/cgi-bin/category.cgi?category=575&item=SOL-80&type=store

What are these other kit charging like $150+ bucks for if it is just a cheap part?

You need to find one with a 100% duty cycle, otherwise the specs on that one were fine. 50% duty meant it needs to be off for 10 minutes for every 10 minutes its on.

the kits are charging so much because you're buying their pre-packaged "solution" - not just the part. I feel its better just to wire it yourself and learn.

Tell you what, give me a few days, I'll put a writeup with a wiring diagram in the Writeups section. I'd rather people did that than wasted their money on the painless setup!

Cue-Ball
11-12-2004, 06:48 PM
That would be AWESOME if you could do a write up.

I would LOVE to save money any place I can. As you know the batteries are expensive enough and then with about $200+ for switches, relays, isolators and all the dual battery thing is getting pricey.

Dirk

nate
11-13-2004, 12:58 PM
No selenoids and no switches. Even better.

I agree.

OverkillZJ
11-13-2004, 03:49 PM
No selenoids and no switches. Even better.

I agree.

Ok, why?

Wiring it parallel is the simplest way to get two batteries into your electrical system, but it has a number of downsides (as does a solenoid)

1. The battereies are in a constant state of draining each other. As one is always slightly weaker than the other, the weaker one is pulling from the stronger, which then makes the stronger one the weaker one. Given this doesn't really cause any damage unless they sit for awhile, but its a problem I like to solve by isolating the battery. Dueling battery syndrome.

2. If both batteres are dead, in parallel, and you jump start it, you're putting a MASSIVE load on your electrical system (ie: ALTERNATER). Especially if it's dual optima's, which drain and absurd amount of power upon being dead and recharging.

3. You only gain the benifit of having twice the battery "available" - but not being able to select one to jumpstart from. I'm a fan of redundancy and having equipment to fail-over to.

nate
11-14-2004, 01:56 PM
Are you just arguing with me for something to do?

Dueling batteries? I think you made that up. I agree if you have on good battery and one dead battery, the dead battery will partially discharge the good one when hooked up. They will equalize. Now take 2 good batteries, they'll be just fine.

Yes, it would be a big load on electrical system. The starter has nothing to do with it... it'd be the alternator. If 2 batteries going dead kills the alternator, well you needed a new one anyway. How do you think it's going to hold up when your winch is pulling 500amps?

I agree with you where it'd be nice to be able to "jumpstart" by switching to the good battery but how often do you leave your lights on? It's not something that happens very often, as least to me anyway.

The benefit of going parallel is that you have twice the amperage. Those 2 750CCA Yellow Tops are turned into a 1500CCA battery. Great for winching or cold starts. Also, the cost is a 2 battery cables, so pretty cheap.

OverkillZJ
11-14-2004, 03:45 PM
Are you just arguing with me for something to do?

Dueling batteries? I think you made that up. I agree if you have on good battery and one dead battery, the dead battery will partially discharge the good one when hooked up. They will equalize. Now take 2 good batteries, they'll be just fine.

Yes, it would be a big load on electrical system. The starter has nothing to do with it... it'd be the alternator. If 2 batteries going dead kills the alternator, well you needed a new one anyway. How do you think it's going to hold up when your winch is pulling 500amps?

I agree with you where it'd be nice to be able to "jumpstart" by switching to the good battery but how often do you leave your lights on? It's not something that happens very often, as least to me anyway.

The benefit of going parallel is that you have twice the amperage. Those 2 750CCA Yellow Tops are turned into a 1500CCA battery. Great for winching or cold starts. Also, the cost is a 2 battery cables, so pretty cheap.

I'm not arguing, I'm discussing a dual battery setup. I believe that's why we're here?

Sorry about the typo with "starter" - should've been alternater.

I didn't make duelling batteries up, I just don't know the right term for it. Think about it, you have 2 rechargable batteres wired in parallel at all times. Unless both have the same voltage and amperate down to .0000001 mv, one is going to be weaker than the other. Therefore, one is always pulling a charge from another. It's a loop.

I leave things on constantly, I'm stupid like that. That's the initial reason I went with the dual Optima setup.

As far as the benefits of going parallel... IT IS PARALLEL with a solenoid. All the solenoid does is isolate one of the batteres when 1. the vehicle isn't running or 2. when you flip a switch. It's a fail safe.

The only benefit I see about hard-wired parallel is the simplicity. Many people have done it this way for decades without a problem, it's just now the way I chose to.

nate
11-15-2004, 12:46 PM
I agree that the weaker battery will pull juice from the stronger battery, but I don't think it will continue in a "loop" until both batteries are dead. I might have to do some research on that.

I see where you are going with using a solenoid. You will just have to find something that can handle the juice, and I'm sure it won't be very cheap. The solenoid that CueBall posted is too small. 225amp, 50% duty cycle. I would guess you'd need something around 500-600amps, and 100% duty cycle.
Maybe I am just not understanding the setup though.

Cue-Ball
11-15-2004, 01:51 PM
The Wrangler NW relay is a 200 AMP continuos duty, is that not big enough?

I am nor really interested in the parallel set up as my initial goal was to be able to "jump" myself. Then when needed I could go to "both" batteries for extra amps.

Mtn WJ
11-15-2004, 09:43 PM
I am planning something a little different. I want to mount a second red top in the rear and set up a charging isolator to keep the rear battery charged up and ready when needed. (similar to a camping trailer battery system) This way I can swap the other battery in when needed or run it in series to work with a trail welder. The isolator are not too expensive and you can get them at most auto parts stores.

Running a solenoid is pretty cool but so is just swaping in a fresh battery.

I have previously used on of those jump start portable batterys for emergencies and it just trickles off a 12v power port. I have a 450 amp version that started my Jeep with no problems. Some of the 200 amp and even smaller ones barely cranked the motor. I think I will give it to my son to charge up his remote car batteries at the track.

happy
11-16-2004, 12:16 AM
how do u set it up so that one battery is only running auxilary lights, winch, etc.? and use the other one for all the other stuff?

OverkillZJ
11-16-2004, 12:31 AM
how do u set it up so that one battery is only running auxilary lights, winch, etc.? and use the other one for all the other stuff?

that's more complicated than it's worth. You'd be looking at some VERY large isolators, as well as solenoids, and better be damn good with understanding both basic electrical concepts, as well as some kind of logic circuit to decide when the battery needs a charge.


As far as welding goes, I came up with a 3-solenoid way to switch the system to 24volts for welding, while keeping the Jeep isolated (and running on alternator power, no battery). Don't know if I'm gonna have time to do that this winter though :-/

Cue-Ball
11-17-2004, 10:45 PM
[quote=Cue-Ball]

Tell you what, give me a few days, I'll put a writeup with a wiring diagram in the Writeups section. I'd rather people did that than wasted their money on the painless setup!

Just wanted to check and see if you had gotten a chance to start thinking about doing a write up on this or not.

Thanks.

OverkillZJ
11-17-2004, 10:55 PM
[quote=Cue-Ball]

Tell you what, give me a few days, I'll put a writeup with a wiring diagram in the Writeups section. I'd rather people did that than wasted their money on the painless setup!

Just wanted to check and see if you had gotten a chance to start thinking about doing a write up on this or not.

Thanks.

Not yet, ask Dave, my time frames on doing things.. SUCKS! ;)

Cue-Ball
11-18-2004, 12:32 PM
I hear yea. I still don't have the new air intake yet and I need that before I can mount the 2nd battery so I am not in a crunch yet.

If you could just slap a material list together even that way I could get the parts ordered I could figure out hooking it up later. It's just I would feel like a dope if I spent the $230ish on one of the kits if you say it can be done for around $50-60 in parts.

Thanks.

RufftyTuffty
11-18-2004, 06:50 PM
Get the JEGS dual battery relocation kit....relo them both to the trunk (only if you have gel batts) = $90

Hook up a PAINLESS isolator/regulator = $120

2nd battery = $100

Looks like about 3 bills.

And let me know how it workz :P

Cue-Ball
11-18-2004, 08:00 PM
Well I already have the 2 yellow tops and 2 battery trays.

I am waiting on my new air intake to arrive so that I can mount the 2nd battery where the stock air cleaner goes (really don't want to have the batteries in the back).

I just got catalogs from Steve up at Wrangler NW and their stuff looks pretty trick and he was really knowledgable on the phone last week when I talked with him.

Just not sure if I want to spend $223.19+shipping on his set up if I can build it cheaper on my own.

Cue-Ball
12-22-2004, 02:46 PM
Okay I am going to go with the WranglerNW dual battery system. They do not currently have a Grand Cherokee kit so they are giving me special pricing to use mine as the test bed to creat a kit.

Raacerx
12-22-2004, 04:40 PM
Okay I am going to go with the WranglerNW dual battery system. They do not currently have a Grand Cherokee kit so they are giving me special pricing to use mine as the test bed to creat a kit.

Hey Cueball, my Wrangler works great. I had it hooked up to a yellow top and red top for the stereo and winch. Only had to use it once and jumpstarted myself quick as a jiff. If you want one, I might be willing to sell it as Im not currently using it. PM if you want.

PS. Im not sure which kit was used but it was on another ZJ for a long time.

Cue-Ball
12-22-2004, 04:50 PM
Okay I am going to go with the WranglerNW dual battery system. They do not currently have a Grand Cherokee kit so they are giving me special pricing to use mine as the test bed to creat a kit.

Hey Cueball, my Wrangler works great. I had it hooked up to a yellow top and red top for the stereo and winch. Only had to use it once and jumpstarted myself quick as a jiff. If you want one, I might be willing to sell it as Im not currently using it. PM if you want.

PS. Im not sure which kit was used but it was on another ZJ for a long time.

PM sent

415 JEEP
03-18-2005, 04:04 PM
Tell you what, give me a few days, I'll put a writeup with a wiring diagram in the Writeups section. I'd rather people did that than wasted their money on the painless setup!

So... overkill... how bout that write up.... if ya got time.

actually i think pretty much have it covered, im gonna go one step simpler and hard wire a switch under the hood for the cecond batt. will i be missing any of the features of your system?

much obliged
-JB

OverkillZJ
03-18-2005, 04:13 PM
I might actually have time next week.. .It's just a poor mans version of what Cue Ball bought. I'm on spring break but work a whole lot, so no promises :rolleyes:

Cue-Ball
03-18-2005, 04:16 PM
I am EXTREMELY happy with the system I bought, and the guys up at Wrangler NW were great to work with.

Check out the pic in my members journal. Turned out sweet.