Specifications: Basic performance parameters: Display color: blue Voltage measurement accuracy: 1% Power resolution: 1% Supply voltage: DC4.0-30V Voltage measurement range: DC0-150V Dimensions: height 15mm/0.59in, outer diameter 25mm/0.98, mounting opening 22mm/0.87in Wiring method: 2-wire or 3-wire automatic identification Color: White Quantity: 1 Pc Suitable for all kinds of batteries, the buttons can be set, and the alarm value can be set. Wiring instructions: Wiring method: 2-wire mode Measuring range 4-30v - Connect the battery negative, + connect the battery positive, V+ dangling Wiring method: 3-wire mode Measuring range 0-150v - Connect the battery negative pole, + Connect the power supply positive pole (4-30v), V+ to the total positive pole Size Description: The opening is 22mm and can be glued and reinforced. The surface is rainproof Note: Transition: 1cm=10mm=0.39inch. The voltage and percentage are linearly related. U-L corresponds to 0% of power, U-H corresponds to 100% of power Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 1 x Digital Voltage Battery Power Indicator (The default 12V lead acid) About model selection: [Factory default second-line lead acid 12v] You can use it directly on lead-acid 12V when you get it. If you use it in other batteries, please reset U-L (undervoltage) and U-H (full charge). More settings are as follows. For changes, please refer to the following method: 1. There is a white high button on the back of the board. Pre the button for 3 seconds to display 1-U, release the button, pre 1 second to display UL, release the button, pre 1 second to display UH, release The button, pre 1 second. Display 4-d; Second, when displaying 1-U, pre the button for 3 seconds, you can fine-tune the voltage measurement. At this time, release the button and pre it again. The voltage will be fine-tuned upwards. Pre and hold again, And then fine-tune it. You can adjust it repeatedly. Wait for the screen. Automatically save and exit after flashing; generally no need to correct The value is added, the stop is preed and Then the button is preed, the value is reduced, and the adjustment can be repeated after the screen is blinking. Automatically save and exit. This voltage value corresponds to 0% of the power. At the time, release the button and pre it again. The value is added, the stop is preed and then The long pre, the value is reduced , and the adjustment can be repeated after the screen flickers. Automatically save and exit. This voltage value corresponds to 100% of the power 5. When 4-d is displayed, the display mode can be adjusted, and the long pre can change the value. V is the voltage mode, % is the percentage mode, and the V% voltage and percentage cycle are displayed. 6. When 5-L is displayed, the power alarm value can be adjusted. At this time, release the button and pre and hold again. The value is added, the stop is preed and then long preed, the value is reduced, and The adjustment is be repeated repeatedly. After the screen flickers, it will automatically save and exit. The default is 10%. When the battery level is lower than this value, the alarm will flash. 7. After each adjustment value is set, wait until the screen flashes automatically to save and exit before proceeding to the next operation, otherwise the new adjustment value will not be saved! Setting example: Set up a battery-powered system. The lowest alarm voltage is 21v. The full voltage is 27.5V. The display mode is only showing the percentage. Set as follows: select 21V in U-L, 27.5V in U-H, and % in 4-d; Frequently Asked Questions: (Q &A) 1 : Power percentage and voltage Do you want to switch manually? A: The default power percentage and voltage values are automatically displayed in turns and displayed in 2 second intervals. Users can also set their own fixed display one. 2 : I don't know how much my lithium battery is. How to buy it A: Lithium batteries are generally divided into two kinds of lithium batteries: 3.7V/3.2v. Lithium in the option is the default 3.7v (full charge is 4.2v) lithium battery. Look at the maximum output voltage of the charger/4.2V to get the number of strings. For example, the charger writes a maximum output of 54.6v. 54.6v/4.2V=13 strings. 12.6V/4.2v=3 strings. Lithium-free parallel connection. 3.2V lithium battery (full charge 3.6v). For example, the maximum output of the charger is 14.4v. 14.4/3.6v=4 strings. For 3.2v lithium battery, customers need to set it up. 3: I don't know my battery U-L, U-H is how much v. A: The general approach is as follows U-L is the battery undervoltage value, you can try to use up the power to finish the observation of how much v