2 Batteries - 1 Volt Gauge - 1 Switch

[brentjsimm]

I'm trying to use my single volt gauge to view the voltage of either the trolling or starter battery, by way of a switch. I have the necessary items to wire it using option 1, but i'm concerned about crossing circuits by using a common ground (trolling battery is not grounded in line with the starter battery. it is only connected to my trolling motor and on-board charger). From you experts, would this be a problem, or no? If it is, I suppose I could resort to option two, with the purchase of dpdt switch. If there's a more proper way to wire this up, I'm extremely open to suggestions. Please and Thank You!

 

[ac0j]

Re: 2 Batteries - 1 Volt Gauge - 1 Switch

option one is what I would do, I dont see the volt meter in your diagram.
You could just wire the battery - together, run a pos from each battery to a spdt switch, common pole of the switch to the volt gauge. no relay required.

 

[Silvertip]

Re: 2 Batteries - 1 Volt Gauge - 1 Switch

option one is what I would do, I dont see the volt meter in your diagram.
You could just wire the battery - together, run a pos from each battery to a spdt switch, common pole of the switch to the volt gauge. no relay required.

The voltmeter is the round gauge at the top of the diagram. If you eliminate the relay the gauge would be active all the time, as would any other gauge on the console since power is generally daisy chained. The relay simply kills the circuit when the key is off. Option 1 is fine as shown.

 

[brentjsimm]

Re: 2 Batteries - 1 Volt Gauge - 1 Switch

Thanks guys.

Yeah, the relay is just so I dont have to disconnect my batteries when I'm done on the water. Theyll only come on when I engage the key, as would gauges in a vehicle.