Suitable for lithium battery and lead-acid battery. The screen can display voltage, percentage of electricity at the same time. (Note: These three can be keyed off.) Can measure an adjustable voltage range of 6-120 V. (Lead-acid battery 12 V for this product) Waterproof and easy to connect with only two wires. Setup Mode: Power on (red for and black for-) Press a few seconds to set the mode: from 1-U, 2-b, 3-C to 4-d. 1-U: Calibration voltage 2-b : Installation Battery Type 3-C : Setting the number of batteries 4-d : Display Mode Setting 1-U: Voltage Calibration: While on 1-U , Press the button to enter the voltage calibration mode, release it and press again, the voltage will be adjusted; release the button and then press it to adjust step by step; repeat the setting and save the settings during the flash of the screen. And there is an installation. 2-b: Battery type adjustment: While on 2-b, press the button to change the type of battery, press one by one, it will be shown: 1.2V _ 2v_3.2v_3.7v_12v (when setting up the corresponding type of battery, release the button, save and exist settings with a blinking screen .) 1.2 V : Ni-MH battery, each battery 1.2 V 2 V : Lead-acid battery, each battery 2 in 3.2 V : Lithium-Iron Phosphate Battery, each battery is 3.2 V 3.7 V : Polymer lithium battery, each battery 3.7 V 12 V : Lead-acid battery, each battery 12 3-C: Setting the number of batteries: During the 3-C setting, press the button to enter the number of batteries in the setting. Release the button and press again, the value will be adjusted; release the button, and then press i T to decrease the adjustment; Repeat the setting for the appropriate number of batteries. Different range for different battery types: 12 V Lead-acid battery: 1-10 sections 3.7 V Lithium battery: 2-28 sections 3.2 V Li-ion battery: 2-32 sections 2 V Lead-acid Battery: 3-60 sections 1.2 V Battery Ni-MH: 10-70 sections Set to the appropriate mode, save the settings during the flash of the screen and exist settin 4-d: Display Mode Setting In 4-d mode, press the button to enter setup mode. Release the button, press it as soon as one mode is shown: V-voltage,% power percent (these two will be in a cyclic display) Set to the appropriate mode, save the settings during the flash of the screen and exist settings Samples for installation:   Technical specifications: Voltage measurement range: DC6 ~ 120 V (wide range), the maximum input voltage can not exceed 120 V Test voltage: DC6 ~ 120 V (Decimal point of automatic switching) Minimum resolution below 100 in: 0.1 in Minimum resolution 100 in: 1 in Energy Resolution: 1% Operating current: <20mA Screen Display: LED External dimensions: L54 x W30 x H21mm Installation Hole: 47.2×27.3 mm Measurement speed: more than 500 ms / time Voltage measurement accuracy: 1% ( /- 2 digits) Lead length:> 150 mm Minimum supply voltage: 6 V Maximum supply voltage: 120 V Operating temperature: -10 ° C ~ 50 ° C Operating humidity: 10 ~ 80% (non-condensing)     Package Include: 1×12 V Lead-Acid Lithium Battery Indicator LED Water-Resistant LED Digital Battery Capacity Monitor Voltage Meter Battery Tester