I've gone through a lot of the threads on batteries and there's just too much there.
The boat is a 2007 Supra 24SSV Gravity Games, with the 340hp Indmar.
I gutted the stereo in my boat. Last year I just used to Stinger batteries for stereo and starting with the OEM battery switch. It's not a Perko switch, but similar.
I'm gonna continue to use the 2 Stinger batteries that I have, but add one of the OEM marine batteries that I removed from it last year.
How should I do this?
1. Use the OEM switch with the boat battery on position 1, then both Stinger batteries on position 2, nothing in between.
2. Forget the switch, wire the engine to the OEM Marine battery, then go from them with a single 4 gauge to this: http://www.stingerelectronics.com/productDetails.aspx?delineate=735&CategoryID=-1&ParentID=-1
, then out to the 2 batteries. Should I just go to one battery, or 2 4 gauge wires to each battery? Instead of wiring the isolator to the ignition, I'll wire it to a toggle switch to keep the stereo batteries isolated until after the engine is started and running. The turning the switch on will connect the stereo batteries to allow them to charge. I realize that my alternator won't charge all 3, but it would be a little.
I'll also be adding 2 on-board battery maintainers for the Stinger batteries.