I've decided to just order a battery switch from iboats, I have a two battery set up in my bayliner capri 1854, 3.0 I/O which was initially for the trolling motor factory installed, i've removed the trolling motor and will be running the second battery just as a back up (just in case).. Which one of these battery switches would you guys recommend?? I've got 2- 500cca marine batteries.