Features: Equipped with an acrylic shell baffle that protects the device from damage and provides a clear view of the display. Support 1~24 series lithium battery pack (voltage between 2V~4.5V battery). Display the voltage of each string, total voltage, highest string voltage, lowest string voltage, maximum voltage difference of the battery pack, average voltage, equalization voltage, number of battery pack strings. Each string voltage accuracy 0.003 or so. With reverse connection, high voltage (more than 4.5V), low voltage (less than 2V) warning sound and prompt. Type-C and DC two kinds of power supply (power supply 5V). Support mixed plug (no need to start from B1). Can switch between English and Chinese. Operation Steps: 1. Turn on the power switch after the device is powered on. 2. The battery pack is wired according to the label on the device or the adapter board. 3. Check whether the display data on the display is normal, if not, check the wiring or the battery pack. Note: The matching adapter board is self-contained 2.0/2.54 pitch pin position, can not be connected to two interfaces at the same time. Specifications: Type: With expansion board / Without expansion board (Optional) Material: Acrylic Model: 24 series Power Supply: Type-C and DC Item Size: 140 * 95 * 36mm / 5.51 * 3.74 * 1.42in Item Weight: 243g / 8.57oz Package Weight: 369g / 13.01oz Package Size: 203 * 140 * 70mm / 7.99 * 5.51 * 2.76in Package List: 1 * Lithium Battery Voltage Detector 1 * Lithium Battery Expansion Board 1 * USB Cable 1 * User Manual (English) OR 1 * Lithium Battery Voltage Detector 1 * USB Cable 1 * User Manual (English)