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BQ77915: voltage issue

Part Number: BQ77915

Hi team,

Issue: Charge the 5-string Li-ion battery with the BQ7791500, and the voltage across the pack drops to 13.4V after 16-V undervoltage protection. Remove load + charge, cannot recover and cannot charge battery.

Could you help check this case? Thanks!

Best Regards,


  • Hello Cherry,

    UV protection should keep the CHG FET on, allowing charge to go through. Can they see if the CHG FET or DSG FET is on? See Table 9-5 in the datasheet for fault condition description.

    I find it strange that the battery pack voltage would get that low. Which part number are they using? None of the BQ77915 offer UV protection at 16-V (See Section 6 of the datasheet).

    Best Regards,

    Luis Hernandez Salomon