Power distribution blocks and dual battery systems.

[steve_r2]

Hello all,
I am looking for help about how I can go about installing a power distribution block with my dual battery system.
Please bare with me on this ...I am totally useless with electronics with sum total of knowledge being red is +ve, black is -ve and knowing how to check the voltage on my batteries.
The reason I am asking for help is my dual set up looks like a complete rats nest of wires to the terminals and I wish to sort it out.
So any good write up's or explanations (in small words, pictures and easy to follow ;-) ) would be great...... I wish to learn just don't know enough or have the confidence to start something like this.
So my wagon is a 2009 Jeep Wrangler JKU fitted with the following:
M.O.R.E dual battery tray
Optima Red top and Optima Yellow Top
Painless Digital Battery Management system
CB radio
Cable running to the rear (trunk) with 12v socket for my fridge (Waeco CF 50), and a dual port USB socket
Warn Zeon 10s.

Will want to add some extra lights, onboard compressor at some stage and also plan on doing the "Big 3" upgrade.
Any help would be greatly appreciated.
Cheers
Steve

 

[Yuccahead]

See this thread.

http://www.expeditionportal.com/for...ke-a-cheap-isolated-dual-battery-setup-for-50

 

[nater]

I think more of what you are looking for is a relay block/fuse block so that one power wire runs off your battery to the distribution block, then you can run all your accessory wires to that. In that case, you have a few options... One I like (and based on your accessories should work is this:

http://pma4x4.com/product/relay-box/
or this for more custom approach to the same thing:
http://www.tacomaworld.com/forum/bu...10-relay-rtmr-5-relay-no-blue-sea-spod-9.html

Of course there is always the sPOD (google it) if you want a really clean, professional look for your JK.

 

[steve_r2]

I think more of what you are looking for is a relay block/fuse block so that one power wire runs off your battery to the distribution block, then you can run all your accessory wires to that. In that case, you have a few options... One I like (and based on your accessories should work is this:

http://pma4x4.com/product/relay-box/
or this for more custom approach to the same thing:
http://www.tacomaworld.com/forum/bu...10-relay-rtmr-5-relay-no-blue-sea-spod-9.html

Of course there is always the sPOD (google it) if you want a really clean, professional look for your JK.

Hater
Thanks for those......that is indeed what I am thinking of .
Cheers

 

[dwh]

 

[gotmud]

I use BlueSea distribution blocks like this:
http://smile.amazon.com/gp/product/B001P6FTHC/ref=wms_ohs_product?ie=UTF8&psc=1

 

[steve_r2]

Ok....one concern I do have .
Checked last night on installation instructions for the Painless Digital Management Kit and since mine was fitted it now has the amendment in the instructions that nothing else should be attached to the aux battery apart from the management kit.
As it stands after physically looking at how the shop wired everything initially I have my winch WARN Zeon 10s, radio (CB), plus two power cables for extra sockets (one with a double USB the other for my fridge) I have in the trunk all going to the aux battery.
By moving these to my Optima Red Top main do I run the risk of killing the main as the management system will draw from the aux only when it senses a heavy load ? Or can I just move my winch connections over and leave the others in place ?
Have attached Painless link for installation of their kit for any further insight.
Sorry for the questions but electrical issues are a black art to me.
http://www.painlessperformance.com/Manuals/40120.pdf

 

[dwh]

Ahh. Didn't notice in your OP that you had the Painless. Thought you were just asking how to install an aux fuse block.

Looking at the manual at the link you posted...

You're right, it seems designed purely to use the second battery when needed to support a heavy load on the main battery, for example, when winching. BUT, it does this by reading the voltage of the main battery. So heavy load or small load, it should *probably* (can't guarantee that, the manual is light on details) tie the batteries whenever the main battery voltage drops for whatever reason. No problem there.

When charging, it will tie the batteries after the main battery is charged to 12.6v or more. No problem there.

And yea, running the aux loads off the main battery will drain it. How far depends on how long you do it. If you draw down the main battery far enough, from what I see in that manual, I would expect the Painless to tie the batteries whenever you cross whatever its low voltage threshold is, and then you would be drawing down the combined battery "bank". That's not a great strategy if you actually want to be sure the truck starts when you need it to.


The way your stuff is wired now, the only gotcha I see is that the Painless deliberately WON'T tie the batteries if the aux battery voltage goes below 11.5v. Well, you're not likely to draw your aux battery down that far normally (unless you're a chronic battery abuser like me), but when you run that winch - while the winch is actually pulling a load - the voltage will drop a LOT. But only until you stop pulling the load, then it'll come back up. So while the winch is actually under load, the Painless will make sure the batteries aren't tied. Not a good strategy for winching.

So running small aux loads from the aux battery is no problem as long as you don't run the battery down below 11.5v. But having the winch hooked to the aux battery will cause the Painless to NOT tie the batteries while winching, which not only totally defeats the design purpose of the Painless, it also makes the aux battery do all the work when winching - AND do it without help from the alternator.



I'd recommend:

Install your aux fuse block to the aux battery. You won't have a problem running aux loads from there as long as you don't run the aux battery below 11.5v.

Move your winch to the main battery so the Painless can work as designed to supply double battery power + alternator to the winch when needed.

 

[dwh]

And yea, running the aux loads off the main battery will drain it. How far depends on how long you do it. If you draw down the main battery far enough, from what I see in that manual, I would expect the Painless to tie the batteries whenever you cross whatever its low voltage threshold is, and then you would be drawing down the combined battery "bank".

(Is it narcissistic to quote yourself?)

Actually, the more I think on it, that part of what I said might not be correct.

The Painless (apparently) has 2 voltage set points. The higher one is 12.6v and when the main battery gets there, the Painless ties the batteries so the aux can charge.

The lower set point is where it sees a large draw down on the main battery, and ties in the aux to support the main. No idea what that set point is, but it might be really low - like 10v or some such. While winching, the voltage of the main battery + winch circuit could drop that low, causing the Painless to tie in the second battery.

But say you moved your aux loads to the main battery, you'll probably never draw the battery down that far. So the battery would certainly be far too dead to start the truck, but might not be at a low enough voltage to cause the Painless to tie in the second battery.

Turning the key and engaging the starter *might* pull the voltage down low enough to cause the Painless to tie in the second battery, which if it was doing nothing else, should have enough power to start the truck.

So really, it just depends on what they've got that lower voltage set point set to. My original statement might be correct, but it might be wrong. I'd have to ask them what that lower set point is to know for sure.

 

[steve_r2]

Thanks dwh,
What you have explained makes far more sense to me at the moment.
So this weekend I will put the winch onto the main and keep the auxiliaries on the other. So hopefully the Painless kicks in on winching with the main and alternator and I rely on it to charge both batteries once the main gets topped up. Will run the auxiliaries from a fuse box ( something like gotmud has suggested ) as I can't really see me drawing down past 11.5 v unless the battery dies of its own accord.
Many thanks for helping me get further understanding of it all.
Steve