1. The drill requires three 15C–20C power batteries or six 10C–15C power batteries (standard 18650 batteries are not compatible). 2. Connect wires strictly according to the voltage markings: 0V, 4.2V, 8.4V, 12.6V, and 16.8V. Do not short-circuit terminals. 3. When using a brushed motor, connect a non-polarized capacitor (rated for ≥25V, 10µF–100µF) across the motor’s positive and negative terminals to suppress voltage spikes and protect the MOSFET. 4. When connecting three battery groups in series, ensure all groups have identical voltage. Charge each group individually before series connection. 5. During discharge testing, the battery group showing faster voltage drop indicates lower performance. 3S 12.6V 40A Lithium Battery Protection Board with Balancing Function for Screwdrivers Compatible with nominal 3.6V or 3.7V lithium batteries (including 18650, 26650, and polymer lithium cells) Charging Voltage Range: 12.6V – 13.6V Maximum Continuous Discharge Current: 40A (reduce load current if cooling is insufficient) Maximum Continuous Charging Current: 20A Type: 3S 40A 18650 Protection Board Color: Green Material: PCB Dimensions: 4 x 6 cm Package Includes: 1 x Protection Board Note: Color may vary slightly due to lighting and screen settings. Dimensions may vary by ±1–3 cm.