So I'm wanting to add a third battery to hook up all my accessories (amps, winches, driving lights, cb, etc...) to keep from risking leaving something on and draining one of my starting batteries. I'm looking for a few suggestions. I know I'll need a battery isolator, and I'll probably get another fuse block to keep everything fused and from drawing too much power. But I don't know where I should mount the battery, how to hook it to the alternator so that it keeps a charge, what size wire to use to go from the battery to the alternator, and what type of battery I should get depending on how it may have to be mounted. Right now I'm thinking I'll probably have to fabricate a bracket to mount it to the frame rail, which I'm perfectly ok with. But if I do that, I'll need a battery that I can turn sideways. What type of battery should I use? Also, what size (amp rating) battery isolator should I use? And can the factory alternator keep another battery charged without bogging down like crazy?

 

optimas can be mounted in other than the up position

your new isolator should have wiring directions and wire size

I have been thinking obout the same thing

 

Yeah, I'm just bad about leaving stuff running when I get out, plus I'm planning on having a M15 or 16.5 winch in the front and my M8 winch in the back, so I want to make sure that if they ever get extensive use, or I have to use them with the truck not running, I don't just completely drain the battery. But Warn's battery isolator is rated for 120 amps. I'm just not sure if I would need more than that or not. A M8 at full pull draws about 250-300 amps easy.

 

honestly I don't think you figure the isolators amp rating by the winch load that would be on the battery
I think it's by the alternators output max

 

http://www.nationsautoelectric.com/tad.html
I bet an isolator for that 3rd alternator would be expensive! JEEZ!