Suitable range: For nominal voltage 3.6V 3.7V lithium battery(Including 18650, 26650, lithium polymer batteries). Charging voltage: 12.6V. Maximum output current: 20A. Maximum output power/charging power: 252W. Successful start of the drill requires three 15C-20C power batteries, or six 10C-15C power batteries (ordinary 18650 can not start the drill). The 0V and 12.6V connecting wires use copper wires of 2mm2 or more, and the shorter the length, the better. Strictly follow the diagram wiring 0V, 4.2V, 8.4V, 12.6V, do not intentionally short circuit. When using a brush motor type load, a capacitor (10uF-1000uF) must be connected in parallel with the positive and negative terminals of the motor to prevent the reverse spike voltage generated by the motor from interfering with the protection board or breaking through the MOS tube. When connecting 3 sets of batteries in series, please ensure that the voltage of each set of batteries is the same. If they are different, please fill each set of batteries separately and use them in series. In the discharge test, the battery with a faster voltage drop is a poor battery.