Hi guys,

Been following this thread over on ExPo, and have looked into hooking up two batteries, and have a house battery and a starting battery, both living under the hood, with my Aussie Battery Tray (thanks Philly). The starting battery is a Diehard AGM Group 31 and the house battery is a Diehard AGM Group 34.

Here's the thread...and I like this guy for two reasons.

How to make a cheap isolated dual-battery setup for $50 - Expedition Portal

1. He likes beer
2. He likes beer

But seriously, he writes his descriptions on a second grade level, which actually works for me, and he is in reality, is a pretty knowledgable guy.

In a perfect world Id love to spend umpteen dollars on fancy LED light bars that display all kinds of pertinent info, and be able to switch between batteries, but this will offer me isolation, and the ability to start the car in the event something happens. That is all I'm looking for, and as the the thread progresses, I'll supply prices, and places, to purchase the items needed to do it. He also list the same thing, and is pretty close.

Plus, the more money I save is the more money I can give Ducameister for a lift when the time comes....and Rigids, and Gobi, and...

I better start rinsing out toilet paper!!

I'll be back to post progress throughout the day...I only have about 12 Yuenglings and a few Sams in the Engel, so obviously it needs to be finished in 4-5 hours.

In the illustration he shows hooking a 12# wire into "on with key" fuse...if anyone has location to find said fuse it would be appreciated!

Attached Images

 

I have done this on three vehicles now. Works great.

looking forward to the results.


take lots of pics bud!

Been watching that thread too. Very interesting and smart. But here is the thing for me: I would rather have cheaper lights than save money on the battery set up. Hell, I would almost have cheap anything else than save money on the battery set up.

Not saying this does not work but all considering it should carefully read all the posts to fully understand its limitations.

Well if you're talking about being able to use one battery, or the other battery, or both...it won't do that (I think I stated that though earlier). In my case I have a Blue Sea 6 circuit box hooked up to the Starting Battery (the bigger of the two) so I already have a big thumper to start with.

The goods..



I'm using 2# by the way for future winch use down the road.

I borrowed a "crimping tool" for the big lugs from my electrical supplier, it comes with jaw sets you change out to match the lug size. They get a coat of applicable color shrink wrap.



God, I'm exhausted...I need a beer..

just out of curiosity, couldnt you use a relay switch to control power to the solenoid?

so... 12v from acc fuse panel to relay. relay is control by a rocker switch.?

that way you would be able to control power to the second battery vs the solenoid simply being switched on when the key turns in the ignition.

I would recommend upgrading the wire, relay and fuses to handle at least the output of the alternator, if not the maximum draw. That means at least 2ga wire and 150amp relay and fuses. The alternator is 140amp IIRC. for the heat shrink tubing the best is double wall, adhesive. It hermetically seals the connection. Don't forget to put insulator caps on the wire at the relay.

The last time I did a setup like this I used a PAC500 500amp marine grade relay and fuses with 1/0 wire. Worked great and lasted for years before the truck went crunch.

jca21,
Yes, that's the way I've always done it. I used a SPDT, center off switch. One side went to the ignition, the other to the 2nd battery, common to the relay. This way when the switch is off (center) the batteries are always separated, when set to the 2nd battery they are always connected, when to the ignition they are connected when the ignition switch is on. I also put a indicator light on the common (to ground) so that it would light up whenever the batteries were connected.

and you're asking ME that?!?...silly boy...I'm playing "monkey see, monkey do"

Thanks Grant, good stuff there!.....as stated above I am using #2 but with 80 amp fuses. I did use the PAC500 btw....found it on fleabay for like 70 smackeroos!

Ok..pic time..

Here's the way it right now...Starting battery..



House battery (or spare)



The PAC 500 mounted(there were two 6mm threaded holes there that fit perfect..I know, I know... I'm a lazy bas****, Antman..you can call me Cantman..hows that?!



Where I'd like to mount the fuse holders..what say the Collective?? Everything can be disconnected very easily and quickly in the event I have to get into the air cleaner or fuse box..thoughts (please hurry though)

The air cleaner side...



Fuse box side (screwed from underneath and siliconed...coz that's just how I friggin' role..

Looks good!!!

Suggestion, run the positive cable in split-loom or at least on top of the negative wire where it goes over the battery hold-down clamp. That will reduce the chance of the positive wire chaffing and shorting out.

You think it's allright to mount the fuse holders in those positions?

Thanks!

Several of us (me included) have made custom brackets for fuse panels in that same location and haven't had any problems.

what kinda battery tray is that for the house battery?

also, moar info on the blue sea fuse block.

The one down side is when using heavy draw while running like winching. That load will want to pull from both batteries. Is is conceivable that you drain both batteries if doing a lot of continuous winching. This also means that you have a larger reserve of power for winching. This usually is not an issue unless you are doing a lot of continuous winching (like 6+ pulls in a row). Also if your wiring and/or fuses are not large enough, you can have issues.

More expensive electronic isolators will only allow power to flow toward each battery and not back toward a load being drawn on one.

The draw on the control wire is very low and 12awg is a lot bigger than is needed. I run off my DRLs and have it fused with a 2amp fuse. I would recommend fusing the control wire too.

Since you have power flowing down the line to/from the second battery, fuse both ends close to the ends.

Lookin good Pat! Couple of things.

I wouldn't mount the fuse holders there simply because they are both access panels, and well, that limits the access. Out in the boonies the KISS method is best. Why make it harder to get to a fusebox if you don't have to? I would mount them to the fender wall, but your spot is OK.

There is some 12ga? red wires on your firewall. Please split-loom them. Naked power wires aren't sexy.

Crossing 2ga battery cables over the battery isn't a great idea. Try to sort the wires out so they run parallel off the battery so they can't touch.

Cantman? Funny stuff! I will be doing something like this in the future. Hmmmmmm.


PS- I don't remember taking those pictures, but uh they are aweful. Welcome to the club bro!

Works great.