Good Times

I've been tinkering of the idea of a dual batt setup. Now I've done some searches on this topic on various different boards and have come up with several different designs for the dual battery setup.

BajaTaco has a great write up using the Pathmaker method:


Slee Offroad has their method:


And finally Hellroar's method:


I'm currently leaning towards the Pathmaker method but I wanted to get some more input from ya guys and see what you thought. What makes one better than the other? I'm pretty sure there are other ways to configure this but I figure these were the popular ones so I just posted these. If you have some other configs let me know. I've also looked at Roger Browns (4crawlers) method too as well.

Cost will be a real big factor on this but I know that after all the toys that I add, the stock batt won't hold. Now should I first go w/ a yellow top batt w/ a better alternator or should I just go all out and do the dual battery?

Now if I should indeed go with the dual batt setup, should I go w/ two yellows or one yellow and one red? Sorry for all the noob questions

BajaTaco

I don't consider myslef qualified to say which one is better. But I will offer you this...

1. If you plan to use really high power toys like a winch and/or welder, then I would go with a system that has a really heavy duty solenoid or switch that can combine the power of the two batteries to provide mega-power for a continuous load. The Pathmaker is not set up to do that. It will combine the batteries for a short session - enough to do an emergency start.

2. Based on the research that I have done, the more expensive systems like the Xantrex Pathmaker, Hellroaring, and others, seem to just refine the manipulation of energy that is being directed through the system. It's my impression that they sense voltage in a more exacting way, so as to more precisely control it - such as voltage spike protection, and being able to fine tune connect and disconnect voltages. They also have less voltage loss across them, so that perhaps they allow a little bit faster charging - or more complete charging. The simpler setups (like a simple isolator) seem like they work just fine though - there are alot of them in use and have been for a long time.

3. The one thing I would NEVER do, is use a system that has a switch that must be operated by YOU in order to isolate or combine the batteries. Relying on our own memory to keep the batteries alive is not a good idea, especially if you have a brain like mine

4. Regarding your batteries - and what you should go with... I think a high output alternator and yellow top is fine if you seldom leave accessories running while the engine is off - OR - if you never plan to run HD stuff like a winch or welder.

5. If you DO run stuff while the engine is off, or want a winch, welder, etc. then I think you would be smart to go with a dual batt. setup. It will ensure that you have the power when you really need it. If you go with a dual batt. setup, I would consider using a Yellow top (or other deep cycle) as your aux. battery for sure. For the starting battery, it depends on how you plan to use it and what kind of battery you get. If your starting battery will only be expected to start the engine, and run the OEM stuff, and maybe your stereo, then a Red Top or regular starting battery should be fine and might be the best choice. If you plan to run anything heavy on the starting battery (like a mega-sound system) then an Optima yellow top is probably a good idea because it can tolerate the heavy continuous loads better. The whole idea with a conventional deep cycle is that it needs to be more deeply discharged between full charges. It's my understanding that the Optima is supposed to be much less forgiving on this rule than old-school deep cycle batteries, and has plenty of cranking power to boot.

Does that help at all?

Good Times

Thanks Chris!

Well since I'm having a winch installed right now I know getting more power is emminent. I have looked into several dual setup and wasn't sure what was best. I've looked into a beefier alternator and a yellow top too as well. Thanks for the insight. I guess this just axes the Pathmaker setup Guess that leaves me with the other two as well as the simpler isolator ones or just going with the beefy alt and yellow.

From you say you don't really like the Slee design because it has a switch where you have to manually isolate or combine the batteries? But if you look at the hellroar, isn't that the same as well? Or do you mean the switch as in a switch that will power both battery regardless? I'm abit confused now.

Ultimately, what I'm looking for is the ability to power the winch along with other electronics inside. There maybe a future for other "appliances?" or what not so I know a dual battery setup will be an eventual process.

I guess I could just easily go with a yellow and a better alt for now. Prob have to do more homework on this b4 I take the big plunge.

BajaTaco

Lance, I'm glad I could help some, but I was hoping not to confuse you. It's really easy for this stuff to be confusing - and I still get confused by some of it too.

OK, looks like we have established that the Pathmaker is probably not the best choice since you will run a winch.

If you decide to go with a Yellow Top and a hi-output alt. - at least you can use that stuff when you decide to go dual batts. and it will just add to the value/integrity of the system. So you can't go wrong there.

I wasn't saying that the Slee or Hellroaring setups were bad - I was saying that a setup where a manual switch is used as the only means to combine or isolate is bad. Both the Slee and Hellroaring setup have an automatic means for these functions. The only manual switch involved is when you decide to combine the power of both batteries for a heavy load circuit such as your winch. One thing to note with the Hellroaring setup is that they suggest you use the starting battery as the primary battery for your winch and accessories, and the auxiliary battery simply as a backup. This would mean that you definitely want the yellow top as your starting battery. I haven't used this type of system, so I am not sure if I would like it (having everything run from one primary battery).

I have to run - but I will come back and check on this thread - and do some more checking with you on this stuff...

Good Times

Well it's slowly starting to make more sense. I guess for the time being I'll just pick up a yellow top and go from there. I'll have to search around for a hi-output alternator for my v8.

I'll still have to look at what everyone has on the dual setup and go from there. Thanks for all the help Chris!

Darx

I don't know squat about what you guys are talking about but I ran across this looking at TJM's bumpers: http://www.tjmbullbars.com/ibs.htm

4Crawler

iTrader: (3)

I've run dual batteries with a basic solenoid connection for years, works well, simple, reliable and its done everything I've needed to do with it:

http://www.4crawler.com/4x4/CheapTri...atteries.shtml

BajaTaco

There you go - awesome. I dig the leads for the backup welding and jump starting - that's cool.

MNBOY

I used a fairly simple setup for my dual battries. (actually three batteries now). I have a starting battery mounted in the stock location under the hood, and two large AGM batteries, wired in parallel, mounted in the bed. (could also be in the cargo space if you have a 4runner). There is 1 guage cable running from the batteries in back, to a high amp marine on/off switch on the dash, then on to the battery under the hood. This way the starting battery is isolated until I turn the switch on, at which point all the batteries are connected in parallel. I can run my welder off the two batteries in back without affecting the starting battery, or I can combine them all to run the winch, which is only used with the engine running anyway. To charge the batteries in back, I bought a little device called a battery combiner from West Marine. Comes in two sizes depending on your alternator output, either 50 amp or 150 amp, and all it does is senses the voltage of your starting battery, and when it is above 13.8v it opens a relay to also charge the second bank of batteries in the bed. So when your alternator is working, it brings up your starting battery to 13.8 and then begins charging the second battery. When the voltage falls to a preset point (13.5v I think) it disconnects and isolates the batteries again. Pretty simple setup to wire, and basically foolproof. It also doesn't have the voltage drop associated with isolators, so the batteries get fully charged. I understand what Chris is saying about not having a switch, but mine has a big red removable key to turn it on, so it is pretty obvious when the switch is in the on position. Hopefully this makes sense and helps.

FirstToy

Lance can you post pics and info on your final solution. I am still in the fog about this and pics in the 4th gen engine bay might help.

Thanks

Good Times

I basically followed Roger Brown's setup as it seemed to be the easier and made the most sense.

I'll see if I can take some snap shots of the setup and show ya

Cebby

One setup I didn't see was using an isolator instead of a solenoid. Some will argue there is too much voltage loss using an isolator, but in reality it is a negligible amount of loss. Isolators don't fail like solenoids either.

Seahawk1

Lance, did you ever get around to taking any pictures? I am interested in a dual battery setup with two Odyssey PC 1200s. I haven't taken any measurements yet, but I was hoping that they would fit in the stock location with only minor modification. If anyone has done this, I would love to hear about it.

Good Times

I have some old photos somewhere but I'll retake some photos to give you a better idea of what I did. I had to relocate my power steering res as I moved the 2nd battery to the opposite side of the factory battery. I was hoping that the Optima battery would fit side by side in the stock location but no dice If your Odyssey battery is small enough that'd be an idea location btw.

All the parts and supplies were straight from Roger's website! He has a complete itemized list of what you need so just get it from there.

Follow up w/ me tomorrow morning if I forget!

Seahawk1

Thanks Lance. I think the setup that I am shooting for is two Odyssey PC 1200s with the Hellroaring Isolator BIC-95300B with Remote Module. I guess the "B" version is dedicated to the back-up battery setup, is simplest to install and is cleaner when finished. The TVS and the sense resistor and external diode are mounted internally. A little pricey but oh well. Now I just need to find somebody that has fit two Odyssey PC 1200s in the stock battery space for the 4th gens. Anyone out there?

neil_P_smith

Ok what if you run dual batteries and dual alternators. I have two alternators one stock, 82 22r and one out of a 93 or so it is the higher amp self-regulating one. I am thinking that I will wire both batteries to a 3 way switch A, B, A+B. then I will leave the stock alternator as is with stock battery as A. then I would run the second alternator to battery B and have it turn on with a switch in the cab. Would this work and do I need any kind of special diodes or any other thingamabob. I don’t do electronics, I get the basics but will leave out the little things.??

4Crawler

iTrader: (3)

An isolator setup is good where you want to isolate the batteries, as in one for the engine and one for accessories, like in an RV or something. If you want dual batteries to run in parallel (if needed) then a solenoid is a simple and effective way to do that, or a big marine battery swtich. Some setups use an isolator and a solenoid. But a good continuous duty solenoid is pretty reliable, mine has worked w/o a hickup for about 6 years now. And if it fails, I still have one battery hooked up and if that battery dies, I can swap cables under the truck in 30 seconds and be on my second battery. Pretty simple setup with one solenoid and one SPDT switch.

MeinPappa

I, too, would be interested in some under-the-hood pictures. Have any of you replaced your stock plastic battery tray?

I have a question about monitoring the setup: Could you hook a simple voltage gauge to the system and wire in a 3 post switch so you could check the voltage on either system (or the combined voltage when running in parallel) w/o adding another gauge?