Be In Your Mind 2Pcs 3.7V 20A 4S Polymer Lithium Battery Protection Board 18650 BMS PCM 55x18mm Red

This protection board is a power-type high-current lithium battery protection board. It has a small size and high current, and can be used in high-current applications such as power tools and model aircraft. Before installing the protection board, the batteries must be well matched (the voltage difference of each battery is no more than 0.05V, the internal resistance difference is no more than 5m, and the capacity difference is less than 30mAh). As long as there is a string of batteries It will protect if the voltage is too high or too low. The better the consistency of the battery, the longer the power of the entire battery, and the better the performance When connecting 4 sets of batteries in series, please ensure that the voltage of each set of batteries is the same. If they are different, please charge each set of batteries separately before using them in series. During the discharge test, the battery with the fastest voltage drop is the bad battery. Don't mix good batteries with bad batteries. The closer the capacity and internal resistance of the battery pack are, the better. Lithium batteries must be charged with a special charger for lithium batteries. Do not use a lead-acid battery charger. Lead-acid charging may cause high voltage to breakdown the MOS tube of the protective board, causing the protective board to be overcharged and not protected.