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BQ21040: Re-charge After a Pre-Charge Timeout

Part Number: BQ21040


The datasheet states that if the battery voltage drops below Vrch (nominally 4.105V), then a new charge cycle is initiated even after the 10-hour timer has timed-out.

The datasheet also states if a discharged battery fails to reach 2.5V during the pre-charge phase after 30mins, then charging is terminated.

The datasheet is clear what would trigger an automatic re-charge after a complete charge, but not a failed pre-charge phase.

Does failing the pre-charge phase stop all charging (until a power cycle) or will the charger automatically attempt a new charge cycle because the voltage is below Vrch?

  • Hi Froylan,

    The failing precharge condition you have described is part of the initial charge cycle that was attempted on power up hence the device will need an adapter toggle to restart charging. 

    In the case where VRCH was hit, the initial charge cycle was completed and it is being recharged. 

    Regards,

    Gautham