Installing a battery gague

[digital1]

I have a Melix 512 and I bought an LED gague to tell me the batery level. After thinking about the instal I think the LEDs will be on all the time. Is there a good way to have it come on with the key?
The gague has 4 posts on the back, pos, neg, R, and another R.
It says the R ones are for an add on that will shut off if the batteries get too low.
I'm not gonna use those for now but can I somehow use the key switch to power this thing?

[BumbleBee]

If you have 36V @ the switch, just make the connection there, add a simple toggle switch to the positive line to the gauge, or you could power it off a relay, but that would be over kill. as long as you get a solid reading you can pull the reading from anywhere.

Good luck.

[digital1]

I tested from the first to the last lead of the battery pack and got 36v. Then I took the wires from the key switch and tested them and got no reading. The key switch does work. Does that make any sence at all?

Coming off the key would be the easiest option but if I need to come off the batteries, do I need a special switch for the toggle. By toggle I mean the switch to turn the gague off when not in use. I have a switch that was on A 12v system for lights, would that be ok to use on 36v?

[digital1]

The switch I have says 18v on the side of it. I assume it would burn up if I wire the batteries through it to the meter. Is there a good place to look for what I need?

[BLakeside]

The meter is designed to use very little current, it can stay on all the time. The switch will work fine, because of the low current draw of the meter. The 18v switch passing up to 44 volts is not a problem. The charger will take the battery voltage up to 44 or 46 during the end of the charge cycle.