i currently have a dual battery setup in my f250 and they are wired in parallel with a battery cutoff switch because the truck might sit for a month at a time. the cutoff switch is all i currently use to disconnect the batteries. i recently added a 9000 winch to the truck and was told that i should have a battery isolator too. what are the benefits of the isolator and how can i wire it in so that my shutoff switch still will kill power to both batteries

 

The only benefit to the isolator is to use one battery for the winch, while the other battery stays fresh to start the truck.

You would have to permanently seperate the batteries, unless you want to do some fancy wiring with solenoids to bring the batteries together. But if one battery is really low, and the other is charged, that's usually not a good idea if the cables connecting them together are very large.

The usual way an isolator is used is when you want to run some elec equipment with the truck off, and a marine or deep cycle battery is used. This way the battery can be run down without damage, and the truck starting battery is still fresh and will start the truck. Once the truck is running, the isolator allows the one alternator to charge both batteries, even though they are isloated from one another.

 

The isolater would allow you to charge both batteries but only use the second one for non running aps. Primary would always stay charged up.

 

http://www.jamestowndistributors.com...itch+-+Keylock
Quick easy to wire in and with a key to lock it out so it adds a bit of security.
Don't forget dielectric grease when you hook it up.