Fuse selection is going to be based on wire size. If jump starting is the goal than don't bother. There is no fusing on the original battery to starter circuit so this is just an extension. If you must you could start with 200 amps as most jump starts relay on the original battery and the jump battery sharing the load. For Anderson battery connectors there are covers. I do not know about covers for the power poles. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Jim Felder
Sent: Saturday, April 11, 2015 3:37 PM
To: vanagon@GERRY.VANAGON.COM
Subject: What fuse would you use for this application?

Today I got around to doing something I have wanted to do for a long time:
I wired in an external 12 connector using an Anderson Powerpole connector set and battery cables. I took the negative from the diesel exhaust bracket, like the vehicle ground, and took the positive off of the starter post.

I put another Powerpole connector on a set of jumper cables. If I want to start my car, start another car, run a 12v shower, I just plug in.

I know others have done this and installed the connectors in various places, but mine is on the underside of my trailer hitch bar. I taped it up to keep it clean, surely somebody makes a blank plug for an Anderson connector. Anderson, say, but I haven't looked yet. That sure is a clever little gadget.

Now that it's done, I am thinking I need to fuse this sucker. Given what I want to do with it, what is suggested?

Jim