autopilot

I'm thinking about buying a tiller autopilot, simrad tp32.
Logical place to install it would be on the aft starboard side cover on my eel 4, but in that conpartment underneath I have batteries so I am worried if the electricity would interfere with autopilot's inbuilt compass. I also read somewhere that outboard engine can cause problems but I'm not sure.
Does anybody have any experience with autopilots on edel 4?
Thx