2 Pieces DC 12V Car Digital Voltmeter Gauge LED Display Voltage Meter Waterproof Voltage Gauge Meter for Car Motorcycle (Green Light)

Used these on my power supply and not very accurate at all ended up getting some different ones from another supplier

These work great stuck on the dashboard. Large enough to see easily. I have one on a 'cigarette lighter' plug and it shows the car battery when the ignition is on; I have the other connected to a portable battery in the car which I use to power my ham radio rig, and now I always know when that little battery needs to be charged.

So far its GREAT. I did tape around the clam shell joint and silicone it, along with the hole for the wires. Just trying to prevent water getting inside. I also used a sharpie to color over the lettering on the outside of it. I wanted it all black.

Works well for my use. I am setting up in house 12 VDC system to run various systems especially for power outages. Nice to just glance and see what battery status is.

Great little voltmeter. I purchased these in a 2 pack. Nice large bright green display with 1-digit accuracy. I mounted one of these on my motorcycle to monitor my stator charging voltage. I am able to easily see the readout even on a bright sunny day. Hookup is simple there is just a positive and negative wire to connect. The display takes about a second or two to initialize. The displayed voltage is accurate, I verified and compared it with a quality DMM. Housing is a nice solid plastic. I mounted the meter with 3m tape and it holds securely. These voltmeters could literally be used to monitor voltage for any 6V or 12V system. The attached wires seem to be around 20 gauge or so and are about 36" long. Great little voltmeter.