Power-lack charging circuit suitable for battery protection system

The utility model discloses a power-lack charging circuit suitable for a battery protection system, and relates to the field of battery protection, the protection system comprises the following components: a power-lack charging circuit, a control circuit and a power supply circuit, and the power-lack charging circuit provides a charging loop for a battery when the battery is power-lack and the battery protection system cannot work normally. According to the utility model, through the arrangement of the power-deficient charging circuit, the control circuit and the power supply circuit, the power-deficient charging circuit is additionally arranged in the battery protection system without changing the performance of the battery protection system, and the power-deficient charging circuit is automatically started to charge the battery when the battery is in a power-deficient state after standing for a long time; when the battery normally supplies power to the battery protection system, the power-lack charging circ