Member #708004

Member Since: August 10, 2015

Country: United States

  • I purchased five of this, and none of them recharges.

    I have 3.7V 40mA batteries as well. 60% of them were not able to recharge when I got them. I had to open them up and re-wire them. It was considered to be as miner problem. It was just messy manufacturer wiring job.

    However 3.7V 110mA batteries much nicer wiring job, however it just doesn't work. I think there is problem with charging protection circuit. Charging protection circuit are used two chips, 8205a and DW01 usually. People who designed this battery use their own DW01, which I think causing the charging problem.

    Since I can upload picture of the schematics, please search DW01, and keep that in mind the manufacturer use their own DW01(It is little bit different)

    So when the normal state, the OD and OC should power two transisters M1 and M2(from 8205a). And when either the voltage at the battery is too low or the voltage at the battery is close to 4.3V then OD or OC will turn off to protect the Battery. It is determined by comparing two voltage difference between Vdd and GND and between CS and GND.

    Here comes the problem. initially before I connect a battery to a charger, OD and OC is close to Vdd. However as soon as I connected the battery to the charger, OC became zero. That means, the circuit thinks that the battery voltage is very close to the 4.3V, which never been true so far.... I suspect CS is shorted to P+(charger power)

    It seems no one has recharging problem but me... Please advise me in this case.

  • I purchased five of this, and none of them recharges.

    I have 3.7V 40mA batteries as well. 60% of them were not able to recharge when I got them. I had to open them up and re-wire them. It was considered to be as miner problem. It was just messy manufacturer wiring job.

    However 3.7V 110mA batteries much nicer wiring job, however it just doesn't work. I think there is problem with charging protection circuit. Charging protection circuit are used two chips, 8205a and DW01 usually. People who designed this battery use their own DW01, which I think causing the charging problem.

    Since I can upload picture of the schematics, please search DW01, and keep that in mind the manufacturer use their own DW01(It is little bit different)

    So when the normal state, the OD and OC should power two transisters M1 and M2(from 8205a). And when either the voltage at the battery is too low or the voltage at the battery is close to 4.3V then OD or OC will turn off to protect the Battery. It is determined by comparing two voltage difference between Vdd and GND and between CS and GND.

    Here comes the problem. initially before I connect a battery to a charger, OD and OC is close to Vdd. However as soon as I connected the battery to the charger, OC became zero. That means, the circuit thinks that the battery voltage is very close to the 4.3V, which never been true so far.... I suspect CS is shorted to P+(charger power)

    It seems no one has recharging problem but me... Please advise me in this case.

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