Repair method of LED rechargeable lithium battery flashlight

LED rechargeable lithium battery flashlight repair and refurbish a yg-859led rechargeable flashlight. After using it for a period of time, the following failures occur: the phenomenon that the brightness of the LED light drops rapidly after only a few minutes after charging for one night. Then, disassemble the flashlight to check. In order to facilitate maintenance, the circuit principle of physical mapping will be explained according to the actual situation for reference during maintenance. The working principle of this rechargeable LED flashlight is relatively simple. This is a current limiting and charge release circuit. The upper 220v AC power of C1 and R is positive, and the current goes through C1,→D1→slide switch battery positive→battery negative→→D4 back to -220v AC power. When the lower end of the 220V AC power supply is positive, the current flows through D3→slide switch, battery positive→battery negative→D2→C1→back to the negative pole of the 220V AC power supply. At the same time, for all other battery anodes, the charging indicator light-emitting diode will return to the negative of 220v AC power when d5-330 current-limiting resistor-C1. When I push the slide switch to illuminate the file position, the white light LED 1, 3, 5, 7, 9, will slide the switch to illuminate the file position Ⅱ, in addition to the white light LED 1, 3, 5, 7, 9, and the white light LED 2, 4, 6, 8 also emit light . Check all components in the flashlight, Φ found the red charging indicator LED D5 reverse leakage phenomenon, after the new change, charging for 12 hours, the fault remains. When this kind of problem occurs, the general problem is the battery. Because of the price of this type of flashlight, manufacturers use mini maintenance-free batteries in order to reduce processing costs. The life of this kind of battery is very short, and most of them are broken after less than one and a half years , It is caused by the decrease of battery capacity due to the evaporation of battery electrolyte. The maintenance method is to replace the new battery or repair the battery. Since there is no such battery supply on the market, and the method of repairing the battery has been followed, there is no effect, and I am going to throw away the flashlight. Imagine that the digital camera in your hand has eliminated 4 2300 mAh and 5 Ni-MH rechargeable batteries. These 4 batteries have stopped working for a long time, resulting in varying degrees of aging. According to the method of sealing treatment, heat treatment is carried out after the pressure cooker is placed, which has some effects, but whether it is using a digital camera or not. According to the principle of waste utilization, the four nickel-hydrogen batteries are welded in series to form a nickel-hydrogen battery pack, the original battery is removed, and the nickel-hydrogen battery pack is connected to the original battery. Turn on the slide switch to test, and the flashlight resumes normal operation. As can be seen from the above picture, the flashlight is a battery, and the charging is controlled by a sliding switch. For safety, do not try to flip the light switch while the flashlight is charging. The charging current of the battery is determined by the current-limiting capacitor C, the formula is as follows: Cu003d14.5i. The unit of C is FI about a, and the derivation steps of the formula are as follows: Assume that the capacitive reactance of capacitor C in a 50Hz AC circuit is xc-1/2? Cu003d1/2x3.14x50xC, Iu003dU/Xcu003d220x2PI?Cu003d 220x2×3.14×50C, then Cu003dI/220×314, where the unit of C is F (Farads), and I is A (amperes), using national international units. If I change the unit of C to F, in order to keep the equation unchanged, I must multiply the right side by 106. ≈14.471 Canadian dollars. It can be used as Cu003d14.5i. According to the formula Cu003d14.5i, the total current of the charging circuit Iu003d69mA, which is basically the same as the actual measured 69.7mA. Even without considering the current consumed by the D5, the full charge time of a 2300mAh battery is estimated to be 33 hours. But that is enough. After the observation, it was fully charged and used intermittently. There was no problem for one month. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.