Battery Isolator

I want to install a battery isolator in my 89 B250 camper van and not too sure what amperage rating I should go with.

The altenator is rated at 120 amps and I will be using a auxiallary deep cycle that will be connected to a 1000 watt invertor which is used on a small fridge.

The most common isolator I can find is a 95 amp and the next one available is 130 amps.
There is a large price difference between the two isolators. Would the batteries ever require anything more than 95 amps? Sounds like quite a bit of currant that anything above that would be unsafe.

Thanks !

I am also running a 95 amp isolator in my van. I also opted for the cheaper 95 amp version since the 120 amp was much more expensive.

I dont think the alternator would ever actually push out that much amperage in an everday situation. Your standard accesories; lights, fan, ignition and the draw from your slightly drained batteries should never cause that much load to be put on the alternator.

Soon after I spent the $60 on the new isolator, I saw them at swap meets all the time. Most of them were basically brand new and I bought a handful for $5-10 each. I figured it's a good price and will no doubt find someone who'll need one.