5pcs Voltage Meter 3 Wire 0.36" DC 0~30V Digital Voltmeter Gauge Tester Red LED Display Panel Mount Car Motorcycle Battery Monitor Led Voltage Display

These are very nice digital voltage displays. The quality is good, but I have added some adhesive to make sure the wires stay connected during handling. That's my only complaint. Some of the wires are stripped a little too much and a little tug might disconnect them, or they might just fail mechanically due to bending during handling. That was not a deal breaker for me as they are inexpensive, not cheap (inexpensive relates to price, cheap relates to quality). When I need more, I'll be back.

but the wiring connection is a little iffy. you may want to dabble some hot-melt glue over the connections for mechanical support and short-protection.

Pretty accurate for the price. Excellent for bench instruments.

Wanted a voltage monitor for a 9.6 V older Makita charger to monitor charging voltage and final cell voltage. Discovered this unit does not tolerate a source of high current until completely initialized. If wired directly across the battery terminals it will eventually destroy itself. Works for a short time, battery plugging and unplugging, but soon conks out, sometimes with smoke. Not knowing the input impedance for current-limiting on the red & black wires, my solution was to place a 100 ohm resistor in series with the white lead and 200 Mfd of tantalum cap from there to Gnd. (black) Crude, but seems to work in delaying power clear long enough for everything to settle down.. Too bad I had to burn 3 devices finding this out.

The voltage meter seems to be within about +/- .3V from my multimeter so pleased with the accuracy and the 3 wires. The quality is very low so expect to resolder all those pads and replace all the wires. Other than that, the voltmeter works. The size is perfect and small as described. The brightness of the display is what I would expect. Design seems great with accuracy within a tolerance but it's quality is pretty low and ill expect some accident breakages.

these are 12 volts, no more

Ok separate power needs all connected by ground line so the yellow wire is the voltage sensor line for measuring whatever and it works really well worth the value for small indication spots

On one, as I was gently unwinding the wires to connect, the wires broke at the solder joint. On the second, the voltage was under by 0.25V compared against my Fluke. These are NOT the version with the pot on the back to adjust, so, these are basically junk.