Battery Isolator

Ok I did a search and have read up about ther Perko Switch and the hellroaring system. I went down to my local parts store and told them what I was after. They sold me a basic starter solenoid for $35.00 cdn. Will this simple device work so I can isolate one of my batteries just for starting? Currently I have two batteries linked together.

Take it back and ask for a Borg Warner R3098. It looks just like a solenoid but functions different. What you have will work but the R3098 is specifically made for battery isolation. It is rated at 200amps cont. and peak over 600. Have been using one for many years with no problems. Stinger sells what apperas to be a rebadged R3098. About $25 bucks at the parts house. Here is a pic in a buddie's X-Star.

The reason I went with the stinger isolator/relay is that ther is no voltage drop across the terminals. The hellroing is the same way. There are other diode isolators that will have about a .7 volt drop across the terminals.