For M18 PCB Charging Protection Circuit Board For Milwaukee 18V 3Ah 4Ah 5Ah 6Ah Li-ion Battery Parts 1. Built-in IC detects the voltage and current of the battery cell, and remembers the number of times it has been used! 2. Detect and protect the battery: overheat protection, overvoltage protection, undervoltage protection, overcurrent protection, overcharge protection. 3. The entire Milwaukee series achieves low-voltage shutdown and is highly applicable! 4. Stable quality and shock resistance, it is the best partner for Milwaukee torque wrenches, impact drills, angle grinders, etc. 5. PCB design may change with changes in supply chain and processing technology. Preparation before assembly: 1. If using new batteries, please note: a. 18650 power lithium battery cells must be selected, b. A set of 5/10/15 batteries must be equipped with resistors and capacitors to make their voltages consistent. 2. If you repair an old battery, please test the voltage across each battery cell. If the voltage is different, please charge each battery cell to the same voltage value. New and high quality Material: PCB Color:blue Size:8.2*3*1.5cm Package Included:1Pc Note: Due to manual measurement, please allow an error of 1-3mm. As different computers display different colors, thank you for your understanding, the actual product color may be slightly different from the image. _x000D_