About the Principle of balance: This module is adjacent to the differential voltage balance, and the adjacent battery voltage difference reaches 0.1V or more. The internal trigger balance is working until the adjacent battery voltage difference stops within 0.03V. There is an adjacent differential voltage when charging and discharging on the battery pack. Trigger balance, the battery pack voltage error will be pulled back to the Perfect value, reducing battery maintenance costs. Balanced BMS Features: High-precision energy transfer equalization, balanced IC, high current 1.3A energy transfer battery voltage balancer, significantly balancing battery voltage, improving overall battery pack efficiency Technical Parameters: Operating voltage range: 3.0-4.5V, -//Lifepo4/18650 lithium battery universal. balance current: Adjacent voltage difference is 0.1V or more (current is about 0.5-0.7A) Adjacent voltage difference is above 0.2V (maximum balance current is 1.3A) The smaller the differential voltage , the smaller the balance current. About Connect: B-, the negative pole of the battery pack (the negative pole of the first battery) B1, the positive electrode of the first battery , the positive electrode of the second battery B3, the positive electrode of the third battery And so on About the Indicator: 1.The indicator is lighting,it mean the Active balancing work for between the batteries. 2.The indicator is no lit,the equalization have been completed or not reach for start-up balancing. 3.The indicator is flash,the equalization not work. colour: green Material: PCB size: 22x30.5x4mm Package Contents: 1 x 3S 1300mA Equalizer Balancer Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.