TOPIC: Voltmeter current draw?

Probably splitting hairs here, but I'm curious. Anyone know approximately how much current is used by a standard analog automotive type voltmeter? I have one installed in my camper but wired it with a 3 way toggle switch so I can switch off the meter and the light when not in use. Thinking about wiring one into my battery box lid. Since I don't currently seem to have a working charging system on my motor, I'd like the voltmeter but I'm stingy about unneeded current draw.

I don't know the answer "technically speaking" Norm, but I would sure put a switch on the voltmeter there as well. They do draw some juice, I don't think you'd want it on all the time. (Would eventually discharge the battery all by itself!) Just my two cents......

Voltmeters have a very high internal resistance, in the mega-ohms range. This is so the voltmeter doesn't load the circuit and change the voltage being measured when placed in parallel with it. In other words, the current draw should be negligible.

Thanks guys. I think I have all the bits and pieces to do it, so full steam ahead! Overton's sells a neat box with built in circuit breaker, LED voltmeter, external hookup terminals, but it's $50. I'd rather cobble up something on my own.

Old style analog voltmeters use a D'Arsonval meter movement that typically draws one mA for full scale deflection. That's not much but over time it will drain your battery. Best to switch it off when not in use.

The battery will discharge itself faster than a voltmeter can drain it.