This is a DIY kits,need buyer to assemble it.
Power display is to take some voltage, perform simulations show the percentage of segments, such as 3.7V lithium battery, take the lower voltage 3V, the upper limit of 4.2V, 4.2-3 = 1.2V, the voltage difference between the lower limit of 1.2V, is the battery Analog power up.
LM3914 can accurately detect an analog voltage, 10 LED display, either Multi-light bar display or a single light dot display.
10 LED Displays the battery voltage,bar display full brightness 42mA, single light shows 4mA.
Support: single lithium 1S (4.2V) ~ 4S (16.8V), lead acid 6V ~ 12V, NiMH 3.6V ~ 18V, nickel-cadmium batteries 3.6V ~ 18V.