Description note:       The protection board can not be used for lithium iron phosphate battery, xenon lamp, hand drill battery pack, can not be used for electric fish battery pack, electric bicycle battery pack, children's car battery, 775 (4A) above motor, 1W fisheye LED lamp, For the above combination of purchase customers please pay attention! .  The power range described applies to the following products:         Massager battery pack, LED lamp backup power supply, 12V electronics, solar street light battery pack, monitoring standby power, and other products. Note: For products discharged above 3A, the battery discharge rate should be 3C or more. Magnification formula: 1C rate battery, 2000 capacity equal to 2AH*1=2A operating current. 3C rate battery, 2000 capacity equal to 2AH*3=6A operating current. In use, the battery will heat up and the battery power is not applicable. This condition cannot be used for a long time and the battery will be damaged quickly. Note 1: Connect 0V (B-), 3.7V (B1), 7.4V (B2), and 11.1V (B+) exactly as shown. Do not intentionally short-circuit! Note 2: After the cable is connected, it needs to be charged before output. Note 3: When connecting 3 batteries in series, please make sure that the voltage of each battery is the same. If not, please fill each battery separately and use it in series. In the discharge test, the battery with the fastest voltage drop is the bad battery.  Explain: Don't mix good batteries and bad batteries together! The capacity/internal resistance of the 3 batteries should be as close as possible (2 good batteries + 1 bad battery use effect = 3 bad battery use results).   The lithium battery protection board properties: Model: HX-3S-FL25A-A  Over charge voltage range: 4.25-4.35v±0.05v Size: 56*45*4.0mm Over discharge voltage range: 2.3-3.0v±0.05v Maximum operating current: 20-25A (note heat dissipation) Working temperature:-40---+50°C Upper limit instantaneous current: 35-40A Storage condition: -40-- +80°C Quiescent current: less than 30uA Effective life: more than 30000 hours Internal resistance: less than 100mΩ Short-circuit protection: protection, delay self-recovery. Balance current: 45 mA Charging voltage: 12.6V-13V Test Point Description: S1 S2 short circuit P + P- will output voltage, indicating that all MOS protection is normal, plus a normally open temperature detection can expand the temperature protection.  The protection board size and device description;  The protection board size is 56*45*4.0mm; Packaging includes: 1 x pcs   SPU:JCL6943