Features: The protections module offers robusts protections for 18650 Lithiums batteries, ensuring safety with features like overcharge, over discharge, and short circuits protections, making it essential component for battery management systems. Note:B - and C-wires should be connecting with thick wire and ensure that the solder pad is correctly soldered to the positive and negative terminals of the corresponding equipment. Note 2: Before installing the protections board, the batteries must be matching properly (the voltages difference between each battery is not more than 0.05V, the internal resistance difference is not more than 5mΩ, and the capacity difference is less than 30mAh). The protections board is design to protect each string of batteries, and any string of batteries with high or low voltages will be protecteds. The better the consistency of the battery, the longer battery lifes, and the better performances of the protective board. Note 3: Single batteries need to be connecting in parallel to form the required number of battery pack before being used. Note 4: When connecting 3groups of batteries in series, please ensure that the voltages of each group of batteries is the same. If they is not the same, please fully charge each group of batteries separately before using it in series. During the discharge test, the group of batteries with the fastest voltages drop is a poor battery. Specifications: Component:Plastic Size:Approx.23.7x54.3mm/0.93x2.13inch Working Current:10-20A Instantaneous Current: 25-40A Internal Resistance:3mΩ Option Type:1s,2s3s,4s,5s; for 18650 Lithiums Batteries; Package Includes: 1pc 18650 Lithiums Batteries Protections Circuit Board note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.