APPLICABLE BATTERY: Supports 3-20 series lithium battery packs, 4-24 series lithium-iron phosphate battery packs, and lead-acid batteries of 12V, 24V, 36V, 48V, 60V, 72V, and 84V. This product also supports a custom mode within the range of 9.5-100V. DISPLAY: Features a digital LCD display with backlight and a reinforced waterproof screen. It simultaneously displays battery voltage and remaining capacity, allowing users to clearly view the battery status. POWER-OFF MEMORY: When the power supply to the voltmeter is turned off, the function settings retain their previous state. LOW VOLTAGE ALARM: The low voltage alarm activates when the battery level drops below 10%, indicated by a flashing display, alerting the user that the battery needs charging. LOW POWER CONSUMPTION: The voltmeter has very low power consumption; in normal mode, it draws less than 15mA, and in low-power mode, less than 1mA. CALIBRATION: Includes a calibration screw hole for zero bias adjustment by turning the screw, providing enhanced accuracy and ease of use. EASY TO INSTALL: Can be easily mounted on a panel using the included nut and bracket. WATERPROOF & DUSTPROOF: Rated IP67 for waterproof and dustproof protection, meaning it can withstand water splashes in most conditions. Color: Black Material: Plastic Package Contents: 1 x Battery Capacity Tester Note: Other items shown are not included. Note: Lighting and monitor differences may cause slight variations in color appearance. Measurement error allowance is +/- 1-3 cm.