0.28 Inch Digital DC Voltmeter 2.4-40V LED Display with Reverse Protection

This 0.28-inch LED digital DC voltmeter provides a compact solution for measuring voltage on vehicles, battery packs, and DIY projects. With a measurement range of 2.4V to 40V, it suits 18650 batteries, cell phone lithium batteries, NiMH packs, motorcycles, cars, and more. The two-wire connection makes wiring straightforward, and reverse connection protection prevents damage if polarity is reversed. A fine-tuning function allows precise adjustment, and the display automatically moves the decimal point: two digits below 10V for detailed battery readings, one digit above 10V for higher voltages. Accuracy is 3‰. The unit draws under 30mA and measures at least every 200mS. Note the input voltage must not exceed 40V.

Features and Construction

The voltmeter combines a small LED display with practical circuitry for reliable voltage monitoring. It operates from DC2.4-40V, includes reverse connection protection, and offers a fine-tuning function. Available in blue, green, red, or yellow, the 0.28-inch display is readable in most indoor and vehicle installations.

Material and Build

The display uses a 0.28-inch LED panel, and the unit comes with two wires for connection. Reverse connection protection safeguards the circuit if wires are accidentally swapped. The fine-tuning function lets you adjust the reading within its range. Working current stays below 30mA, and measurement rate is at least 200mS per reading, supporting regular monitoring without drawing significant power.

Size and Practical Fit

The compact 0.28-inch LED display fits into small panels or enclosures where space is limited. It measures voltages from 2.4V to 40V, with automatic decimal point adjustment: two digits after the decimal point below 10V, and one digit above 10V. This suits both low-voltage battery monitoring and higher-voltage checks. Operating temperature is -10 to +65°C, humidity 10-80% without condensation, and air pressure 80-106kPa.

Uses and Placement

This voltmeter is intended for measuring battery and vehicle voltages. It can be connected to car, motorcycle, or battery car interiors, and also works for other voltage measurement purposes within its range. Keep it away from direct sunlight and within the stated environmental limits.

Event or Professional Use

For automotive or battery workshops, the voltmeter offers a quick way to check voltage on motorcycles, cars, and battery packs. The two-wire setup simplifies temporary or permanent installation. Reverse connection protection reduces the risk of damage during wiring. The fine-tuning function helps maintain accurate readings where slight adjustments are needed.

Everyday Home Use

At home, use it to monitor 18650 batteries, cell phone lithium batteries, NiMH packs, or other battery packs. The 0.28-inch LED display shows voltage clearly, and the automatic decimal point gives more detail below 10V. Below 3.0V the display dims but still measures correctly. Always keep input voltage under 40V to prevent damage.

Benefits and Buying Value

This voltmeter provides a straightforward way to check voltages without complex setup. Its small size, two-wire connection, and protective features make it a practical addition to vehicle or battery monitoring tasks. Available in four colours, it can match different installations.

Reuse and Low Maintenance

The unit has no moving parts and draws less than 30mA, so it can remain connected for regular monitoring. Reverse connection protection helps prevent damage from wiring mistakes. With a measurement rate of at least 200mS, it updates quickly enough for most checks. Avoid exceeding 40V and keep within the operating temperature and humidity ranges to maintain function.

Why Choose This Product

Choose this voltmeter for its 0.28-inch LED display, 2.4-40V range, and automatic decimal point adjustment. The two-wire connection and reverse connection protection simplify installation, while the fine-tuning function allows small adjustments. It suits 18650 batteries, motorcycle and car batteries, and other voltage measurement needs. Package includes one digital voltmeter.