Add on volmeter w/ painless dual battery setup

I am running dual batteries with a painless dual wiring kit on a 97 xj. I recently purchased an autometer sport-comp volt gauge. I purchased it for showing how much juice is in my second battery. (The guessing game will finally be over)
I tried to install it today and in the instructions for the gauge say to wire it to either an ignition switch or an other switched 12 volt source. Now I know I could wire it to a switch and then to the second bat. But I would always have to turn the switch on and off. (I think this would become a pain)
My question for you guys: Is there any way I can wire it into the ignition system so when the car is turned on the gauge comes on automatically?
Has anyone done this before with a painless wiring kit?

Thanks,
Adam

take the power from the painless solenoid. there is one terminal that is ignition sourced

Dumb question, why not put in a second VOLTAGE gauge to measure the second battery ? Unless I'm mistaken the dual battery systems work two ways, one is parallel and the second is isolated using a switch.

RNMedic said:

take the power from the painless solenoid. there is one terminal that is ignition sourced

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I will give it a try...

RichP said:

Dumb question, why not put in a second VOLTAGE gauge to measure the second battery ? Unless I'm mistaken the dual battery systems work two ways, one is parallel and the second is isolated using a switch.

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i dont reallty understand why this is a dumb question... I am putting a second voltage gage to the second battery... but i dont want the gauge to work just when the second bat is being used. I want the gauge to come on with the when the ignition switch is turned.

what would you suggest?

Trbocharg said:

i dont reallty understand why this is a dumb question... I am putting a second voltage gage to the second battery... but i dont want the gauge to work just when the second bat is being used. I want the gauge to come on with the when the ignition switch is turned.

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I was referring to my dumb question, on the ambulances and crash trucks we had 4 to 8 batteries, each battery had it's own meter, none of them worked until the key was turned on then they all came online. Thinking back I don't remember whether they were voltage, or percent charged, percent charged seems to come to mind though as the numbers went from 0-100 with a graduated color scale. Too many years ago to remember the details...

Trbocharg said:

i dont reallty understand why this is a dumb question... I am putting a second voltage gage to the second battery... but i dont want the gauge to work just when the second bat is being used. I want the gauge to come on with the when the ignition switch is turned.

Click to expand...

I believe the device you are searching for is a relay.
Relay coil between ground and accy on the ignition switch, relay contacts in series with the voltmeter (+) lead to the aux battery.

So when the accy lead off the ignition switch gets power, it closes the relay contacts and connects the volt meter to the battery.

Zuki-Ron said:

I believe the device you are searching for is a relay.
Relay coil between ground and accy on the ignition switch, relay contacts in series with the voltmeter (+) lead to the aux battery.

So when the accy lead off the ignition switch gets power, it closes the relay contacts and connects the volt meter to the battery.

Click to expand...

I found some information on relays at http://www.kpsec.freeuk.com/components/relay.htm
It seems like one will def work in this situation.
Thankyou for sending me in the right direction.
Do you recommend any certain relay from any specific manufacturer?

Also if I use the relay method how much voltage drain will occur from the gauge to 2nd bat connection? The reason I ask this is because when using the painless kit the 2nd bat is the one that is used purely for starting the vehicle. I leave the car in the accessory ON position over night while camping to run an Engel fridge and a fan when it gets a little to hot. (I sleep in the back of the truck)
Will this gauge connection drain enough voltage to make a significant difference in let’s say a 10 hour time period? I really need that 2nd bat to be fully charged in the morning.

drain from the guage should be next to nothing. a few mAH. Your bat will be fine.