T-HOT Digital Voltmeter DC Voltage Display 0-33.000V (0-33V) 5-Digits Bit High Precision Voltage Meter

TL;DR - Accuracy is much greater than the spec. The display is bright. The documentation is in Chinese but has been translated below. good bang for the buck. Details: the meter came boxed in a hard plastic case to protect it. See attached images so the packaging and instructions. the instructions are in Chinese but it is pretty easy to figure out. Accuracy I found it to be only 4.8mv off at 7.7000V which is 0.06234% error rate this exceeds its spec of +/- 0.3% the test was done with a 120000 count meter that is in calibration. current requirements. I found it to pull 24ma at 7.7v I did not do current tests at other supply voltages but I did test the advertised supply range with no issues. specs: DC Bidirectional Voltmeter DC Bidirectional Voltmeter Working voltage: DC 4~28V (5~12V recommended) Measuring range: DC -33.00~+33.000V Accuracy: +/- 0.3% Definition of lead wires: Red wire (Red): VCC~instrument working power positive pole Black wire (Black): GND~common negative pole Yellow wire (Yellow) V++~measurement power supply positive pole Lead Length:145mm Product Size: 47.6x28.7x20mm Installation hole: 45.2×26.0mm Package size: 52×68×24mm product weight: 30g (including package) I hope you found this helpful

Two major problems with this T-HOT voltmeter, it is slow to update and not accurate enough with no way to recalibrate it. And it has already failed. Was using it to monitor a 12v power supply with the meter powered from a separate source and now the meter is reading 34 volts even though the power supply output is actually 12.4 volts. Tried powering it on/off/on a few times but did not fix it. With the meter input grounded, it is reading a negative voltage. Confirmed the actual input V with one of my Fluke meters. Definitely has failed.

I am very impressed. The readings are spot on when measuring 12V and 24V, at millivolt resolution, compared to my CALIBRATED DMM's. Run them off a 9V battery to isolate from DUT (device under test). Only downside is that two of these meters will kill a 9V battery in one day, if you leave them ON.

I planned to put this on a lawn tactor to monitor the battery and charge voltage, but elected to go with a round meter that was brighter and easier to mount. In terms of performance, this meter was as accurate as a 3-1/2 digit DMM I've been using for years. I did notice the readout seemed a bit noisy, but it improved when connected securely to the voltage source. The meter can be powered by the voltage being measured by connecting the yellow and red leads both to the voltage source "+". Use of separate power and measure leads makes it easier to build a voltmeter powered by a 9V battery, although I don't know how long the 9V battery might last. After installing the round voltmeter in the tractor, I didn't revisit working with this item. Some chilly winter day....

The meter was exactly what I needed to complete a high power analog power supply.

Not very accurate as the multi-decimal digit display would suggest. I returned it.

My son needed a voltmeter to show the voltage for his hovercraft experiment in the 2025/2026 Science Olympiad, with readings up to two decimal places. Unfortunately, when we connected this product to a bench supply and fed it 12V, it displayed 0.0012 volts instead. I was expecting something around 12.xy volts.

Accurate and easy to view.