Battery charging circuit and device

The utility model provides a charging circuit and device of a battery. The charging circuit comprises a power supply module for outputting DC voltage; the DC/DC conversion module is used for reducing and outputting the DC input voltage provided by the power supply module; the DC/DC conversion module is also provided with a feedback input end; the output end of the charging module is connected with the positive electrode of the battery for charging the battery; one end of the sampling resistor is connected with the output end of the DC/DC conversion module, the other end of the sampling resistor is connected with the input end of the charging module, the input end of the feedback module obtains current sampling signals from the two ends of the sampling resistor, and the sampling signals are amplified and then input into the feedback input end of the DC/DC conversion module; the MCU is connected with the enabling end of the DC/DC conversion module and the enabling end of the charging module, so that the DC/DC c