Willys CJ2A Dual Battery Installation

I have a Warn M8000 winch on my CJ2A, and due to the lack of room in my engine compartment (2.0L Ford engine), the battery is a little smaller than what Warn recommends (its a 650 CA with 525 CCA, and Warn recommends 650 CCA). I decided to install another battery, but there isn't a lot of spare room in a Willys. After considering all the options, I decided to use a 20MM ammo can as a center console and mount a 1000 CA battery in it, wired in parallel with the battery in the engine bay. This gives me 1650 CA which should be plenty.

I was originally planning to use 2 gauge welding cable but discovered that it would cost me $100 for the cable alone. 4 gauge welding cable would be about $60. I checked out Wal-Mart and found a set of 20 foot, 4 gauge jumper cables for about $25. I thought about buying two sets and tying them together to effectively give me 2 gauge worth of cable, but I'm sticking with 4 gauge for now. I would really prefer 2 gauge, but there are a few reasons why I am going to go with 4 gauge for now:

Cost - $25 as opposed to $50
I've used my winch with just the 650 CA battery, and it has done just fine, so this second battery is probably redundant
I don't need to pull big amps out of the reserve battery; when using the winch and such, the 650 CA will be used, and the 1000 CA will contribute whatever it can via the 4 gauge cable. After the winching operation, if the 650 CA battery is low, the 1000 CA will recharge it.
If I find that 4 gauge isn't cutting it, I can buy another set of jumper cables and add them to make it 2 gauge. Even then, the cable cost will end up at half the price of welding cable.

The jumper cable wire isn't as flexible as welding cable because it doesn't have as many strands, but it seems sufficient for this purpose. Time will tell.

I just wired the batteries up in parallel for now. One drawback to this is that disconnecting the negative battery terminal doesn't actually disconnect the battery anymore, since the auxiliary battery is always hooked up. I will probably purchase an inexpensive battery cutoff switch to install in the line that runs to the negative auxiliary battery lead, this would allow me to disconnect the battery by removing the negative cable from the engine bay battery and flipping off that switch.

Click on any pic to bring up the full sized version.

	`Thu 5/3/07` A pic of the 20mm ammo can mounted in the Jeep. I thought I took some pics of this process, but I can't seem to find them. Basically, I made a 1/8" steel plate which I bolted to the floor and the ammo can is bolted to that. I have a piece of wood in the bottom of the ammo can which the bolts run through. The wood is there so the bolt heads can be countersunk into it to give the battery a smooth surface to sit on.
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	`Thu 5/3/07` Another view of the ammo can. I picked this up on eBay for a little under $20.
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	`Thu 5/3/07` The Wal-Mart jumper cables I used.
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	`Thu 5/3/07` Also a Wal-Mart item, an EverStart MaXX 1000 CA battery. I've put duct tape over the side terminal protectors to ensure they will stay in place and not contact the side of the ammo can.
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	`Thu 5/3/07` This is a wood piece which fits over the battery which will help to hold the battery in place and protect the terminals from other items in the ammo can.
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	`Thu 5/3/07` A view of the wire coming up through the floor of the Jeep and into the ammo can.
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	`Thu 5/3/07` The battery is in place and wired up.
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	`Thu 5/3/07` Now the cover is placed down over it. Several wood screws go through the outside of the ammo can and into this cover to hold it in place. A separate wood piece gets put down in front of the wooden cover, and this is actually what will prevent the battery from sliding forward in a sudden stop.
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	`Thu 5/3/07` I've still got plenty of room for my Hi-Lift base plate, winch control, vehicle paperwork, and other items.
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	`Thu 5/3/07` The red cables connect to the 650 CA battery in the engine bay and run down to the frame.
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	`Thu 5/3/07` They run into the frame, and pieces of rubber are used wherever it looked like chafing was possible.
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	`Thu 5/3/07` The cables run through the frame...
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	`Thu 5/3/07` ...until they run up into the floor and the ammo can. (One nice thing about a rusty tub is that drilling additional holes is usually not necessary...)
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	`Thu 5/3/07` Just a pic showing what the console looks like with the seats installed and the cover in place.
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This page was last updated Thu May 3 20:52:02 EDT 2007