Perko battery selector switch

[awthacker]

I thought I understood how this device works, but have gotten pretty confused - and I'm having trouble getting my electrical system working properly.

On the back, the lugs are "1", "2" and "common". My understanding was to tie the +12V lead from battery 1 to "1", +12V lead from battery 2 to "2" and everything from the boat (+12V to bus bar under helm, +12V to engine) to "common" (middle lug - currently only has engine lead connected in picture).

I guess what this offers is that I can run off battery 1 all trip, then switch to battery 2 if needed. Next trip, run battery 2 with 1 as the backup. Using the switch this way would offer one battery as backup reserve each trip. I don't think I would ever use the "Both" selection on the dial.

This seems different from alot of wiring setups I've seen, where one battery is the "house" and one is the "starting". Is there an advantage to this system?

What is the best way to use the switch?

Thanks,

Aaron

[phatdaddy]

i guess if you have a deep cycle for the house and a cranking battery for starting you don't want them to draw on each other and a left on switch won't keep you from starting. you also are only charging the one your switch is on. i have 2 batteries (1000 mca) and i have them hooked up parallel. i run off both and charge both. if i need a jump, i call tow boatus. you can buy a charging isolator that will automatically send the charge to the weakest battery.

[spareparts]

you're not suppsoed to mix deep cycle and starting batteries in the same circut, although i see it all the time. Add a battery combiner to the circut, it allows both batteries to be charged, during a high amp discharge, it disconects, or when batter voltage gets low, it disconects. BTW, you have it conected correctly, check into the combiner,not a isolator. an isolator achives the same results, does it a little differently and is harder to wire, the combiner is easier to install

[csvencer]

That switch is designed to run two of the same batteries separately, ie. two starting batteries that are charged and used separately (unless on both, obviously). If you have a deep cycle and a starting battery you want to get one of the off-on-combine switches and a charge relay. The off-on-combine allows you to turn on both batteries on their own circuit (electronics on the deep cycle, motor on the starting) and the relay lets you charge both when the boat is running. If for some reason your starting goes dead then you can switch to combine and start off them both, if you run your deep cycle dead with the stereo, you still have a perfectly fine starting.

Make sense? It's easier to show someone, so if I didn't explain it I am sure I can whip something up in MS paint!

-Svence

[awthacker]

Thanks for the info guys... sounds like the easiest thing to do is to replace the deep cycle battery w/ another starting battery. Luckily, I have one standing by.

[spareparts]

keep both your starting batteries, and if you want to get trick, keep the deepcycle, adn a charging relay, run the electronics off of it, it will be separate from teh engien circut unlees the engine is charging it. BTW, make sure you don't overlaod the charging circut on your motor