1.4 series 16.8V 40A lithium battery protection board (with its own recovery function - AUTO Recovery); 2. Integrate 10 imported low internal resistance MOS tubes, continuous discharge 40A, 100mA balanced current, suitable for electric drills, sprayers, LED lights, low-power inverters; 3. Scope of application: suitable for nominal voltage 3.6, 3.7V (including 18650, 26650, polymer lithium battery), 4.2V lithium battery with full voltage 4. Suitable for electric drills with starting current below 80A power below 230W, with balanced charging function 5. The high current heating is reduced by 30%, the anti-interference function is increased Conditions for successfully starting the electric brick: 1, 4 15C-20C power batteries or 810C-15C power batteries (ordinary 18650 power drills are required!! 2. The connection line between the battery pack the protection board should be as short as possible as thick as possible; 3. When welding the battery for the first time, do not need any load or any equipment at the output end. 4. If it still can't start, please contact the shop king again to tell you the solution. Precautions: 1: 4 10C-20C power batteries, or 8 5C-10C power batteries are required to successfully start the electric drill (recommended power battery models: VTC4, VTC4A, VTC5A, VTC6) 0V 12.6V connecting cables, use 3 square mm above copper wire (nickel sheet cannot be used!!) 2: Strictly connect 0V, 4.2V, 8.4V, 12.6V, 16.8V according to the diagram, do not touch any components on the board when soldering the wires, do not intentionally short-circuit. 3: When the battery is welded for the first time or is being charged, as long as a single battery exceeds the 4.2V430 resistance, it will heat up discharge (discharge to about 4.19V stop heating). If the 430 resistor is seriously hot (don't dare to touch it when it is too hot), please check whether the wiring is wrong Product weight: 10.3g Colour:green Material: PCB Size:45 x 60 x 3.4mm Package Contents: 1 x 4 string equalizer board Only the above package content, other products are not included. Note: Light different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.