Battery isolator

I'm thinking of adding an additional battery to my setup, which is pretty much stock so far. I think the optima yellow-top is the right one, but I also want to isolate it from the rest of the system so I can play music with the boat off and not worry about draining my starting battery. Basically I want two complete seperate electrical systems on my boat, one that is completely stock for the power, and one for audio. How do I set it up, and how do I recharge it. I'm pretty mixed up so far, so any help would be greatly appreciated.

simplest way is with a battery isolator. Alternator charges both batteries, but isolator keeps stereo battery from draining main. wiring instructions come with isolator. they can be had at any rv supplies or sometimes you might find them at walmart type places

Thanks a ton.

Do yourself a favor and check out the Hellroaring isolators. Pete (Cyclone) did a 'why' and 'how-to' here: http://www.epicmarine.com/how_to.htm

The thing that makes sense to me is that the cheapest isolators will allow two banks to discharge separately, but charge both banks as one - the result is somewhat overcharging one and somewhat undercharging the other (both bad).

The more expensive isolators handle both sides independently in both discharge and charge cycles. The problem with most of these is that they always drop the charging voltage by 0.7 vdc by nature of their internal diodes. Unfortunately, this means that both banks are always undercharged by 0.7 vdc.

The Hellroaring ioslator handles both banks completely separately, and the voltage drop is much less than the diode versions. Pete mentions that the this isolator's probably overkill, but the reasoning behind it is sound. And friggin batteries are expensive, huh?

I to recommend the Hellraoring. My dealer had never seen/heard of them and wouldn't install it. I did it myself. Piece of cake. Now the dealer is looking into getting few to "test" themselves.


I think it's the best solution out there. No switches to forget to change.....

th stiger isolator/relay is basically the same thing. I am very pleased with this , and no voltage drop at all. The best thing is no switch to remember.

www.stingerelectronics.com

i am installing the stiger isolator/relay. my question is where do i hook up 12v wire that tells the isolator when the engine is cranking?

I hooked mine up to the ignition switch, just tie in to the 12v pole on the back of the switch.

ok, thanks for the information.