Isolated battery

[Malaki86]

After having an almost dead set of batteries two times in the past two days, I need to figure this out.

First off, I'm in a company truck. I've talked to our shop foreman about adding an isolated battery and he's fine with it. They'll even install everything for me, I just have to provide the materials.

I have a 1,500 watt inverter that's hooked to my trucks batteries (4 batteries). The inverter only runs my laptop when the truck is shut down. If I need to use the microwave, I start the truck.

The only other thing that runs constant is my cooler. It's a 12-pack sized Rubbermaid.

I noticed that if I shut off the cooler when I'm shut down, the batteries do fine the next morning.

Anyway, what I want to do is to add one or two deep cycle batteries that the truck will charge, hook the inverter and cooler directly to them. What I was thinking would be to add a battery isolator, such as this one:
http://www.jcwhitney.com/2-BATTERY-S...0926_10101.jcw

The question is, how would this be wired to the truck? It has 3 posts, which I know what they are - battery 1, battery 2 and alternator. So, how would that work in the truck?

Any ideas?

[allan5oh]

Sounds like you just need new batteries, have the current ones load tested.

[Doghouse]

That cooler shouldn't be running your batteries down like that. Allan is right replace them and you'll be fine.

[Rawlco]

If they will install it then the question of how the wiring goes isn't your problem exactly.

I guess I would interpret those three points on the isolator you linked to as:
1) Starting Battery(ies) positive
2) Isolated battery(ies) positive
3) Alternator positive