Dual Battery Wiring

One thing I noticed- make sure you fuse both batteries.   I'm curious, why do you feel the need to add a second battery?

I'm not sure of the difference of the isolators- the descriptions on that page are the same.

Well, the stock wiring is already protected, but you added a wire up front to run to the back battery.  This wire needs a fuse at the front battery as well as the back one.  Think about it- if the wire shorts between the fuse (you connected in back) and the front battery- your car could catch fire because the wire still gets power from the front battery.

there are only 2 reasons to run a multi batt set up.  1.If you have a high compression motor. Such as a big deisel, some are 21:1 your car is only 8.5:1 stock. you need the cranking amps of multi batts to turn over those big motors. 2. So you can play your music longer or light your lights longer or what ever you need the power, without your motor running. When your motor is not running then your isolator is isolating your other batts. Whats the point in that? When you motor is running your alt is powering your system multi batts are doing nothing, but getting charged. If someone is dumb enough to run down their batt playing music, then they should just get some jumper cables and ask for a jump.