Dual battery question.

[77 casa grande]

I'm running dual batteries, one battery for starting, headlights, hvac controls,ect, the other, a deep cycle for the inverter, stereo, cabin lights and, on board air compressor both charged by a single alternator with a isolator.
I have a Viair 480C compressor with a 5 gallon storage tank ,air horn and 150psi pressure switch/relay which is turned on and off with a toggle switch.
My problem is that sometimes I forget to turn on the compresssor on when I get in, result no air horn, or forget to turn it off,letting the compressor cycle on and off somtimes for days at a time.
My question (finally) is can I wire the relay to the igniton switch while still powering the compressor from the deep cycle battery and still keep the two systems seperate? Will there be power bleeding from one side to the other?
Everything is working, should I leave everything alone or am I just asking for trouble?

 

[CGT80]

a relay should work fine. I run 2 batteries, one for truck, and other for stereo and trailer power. I ran a relay so that my head unit would turn on when I turned the key on. I haven't had a problem with discharging. The isolator I have (power master) reduces my charging voltage to 13.5v though and the powermaster 160a alternator is hell on alt belts.

 

[Fordum]

Not a problem. Unless you wire them together, standard mechanical relays give total isolation between the coil and the contacts.
Its pretty much what they are for.

Thats why you could use 12 volts to switch a 1000, or vice versa.

Of course, you might want to check out your air leaks. If all you are running is air horns with a connection to air tires up, that tank should not leak down enough to let the pump come on.
The usual source of an air leak, is an quick detach air hose connector. They are not supposed to leak, but most of them do.
Easily fixed with a small ball valve. Just leave it off all the time except for when you need the hose hooked up.
The horn can stay hooked up all the time.

 

[77 casa grande]

Thanks for the quick response. I thought it would be ok, just had to make sure.
As for the leak.Its several hours before the compressor switches on but this is not a DD and may sit for a week or more before being used again. Now with the winter coming its used even less.