A charging control circuit for a mobile device being configured to be charged by a mobile charger (102; 902), the charging control circuit comprising a device-side connector and a battery, wherein the mobile charger (102; 902) comprises a power converting circuit and a communication interface, while a power output path is arranged between the power converting circuit and the communication interface, the charging control circuit comprising: an input switch, positioned on a power input path arranged between the device-side connector and the battery, wherein the device-side connector is configured to be detachably connected to an output terminal of the mobile charger (102,902) such that when the power converting circuit transmits a DC voltage signal (Vdc) and a DC current signal (Idc) to a charging cable through the communication interface, and the charging cable provides an output voltage signal (Vout) and an output current signal (lout) to the output terminal detachably connected with the device-side connector, the device-side connector receives power transmitted from the output terminal; a device-side sensing circuit, arranged to operably sense signal on the power input path (Vin; Iin; VB; IB); and a device-side control circuit, coupled with the device-side connector and the input switch, and arranged to operably control the input switch; characterised in that the device-side control circuit is arranged to operably generate a corresponding device-side voltage value based on sensing result of the device-side sensing circuit, or to operably read the device-side voltage value from other circuit, and when the mobile charger (102; 902) transmits a charger-side voltage value corresponding to signal on the power output path (Vdc; Idc) to the device-side control circuit through the data signal (DATA), the device-side control circuit is arranged to operably calculate a difference between the charger-side voltage value and the device-side voltage value to generate a voltage drop estimation value of the charging cable; wherein the device-side control circuit is further arranged to operably generate a corresponding adjustment instruction based on the voltage drop estimation value, and to operably transmit the adjustment instruction to the mobile charger (102; 902) through the data signal (DATA) to instruct the mobile charger (102; 902) to control the power converting circuit to maintain the output voltage signal (Vout) and the output current signal (Iout) supplied to the mobile device in a safe range by adjusting the magnitude of at least one of the DC current signal (Idc) and the DC voltage signal (Vdc) so as to control a voltage drop of the charging cable to be less than a predetermined threshold. an input switch, positioned on a power input path arranged between the device-side connector and the battery, wherein the device-side connector is configured to be detachably connected to an output terminal of the mobile charger (102,902) such that when the power converting circuit transmits a DC voltage signal (Vdc) and a DC current signal (Idc) to a charging cable through the communication interface, and the charging cable provides an output voltage signal (Vout) and an output current signal (lout) to the output terminal detachably connected with the device-side connector, the device-side connector receives power transmitted from the output terminal; a device-side sensing circuit, arranged to operably sense signal on the power input path (Vin; Iin; VB; IB); and a device-side control circuit, coupled with the device-side connector and the input switch, and arranged to operably control the input switch; characterised in that the device-side control circuit is arranged to operably generate a corresponding device-side voltage value based on sensing result of the device-side sensing circuit, or to operably read the device-side voltage value from other circuit, and when the mobile charger (102; 902) transmits a charger-side voltage value corresponding to signal on the power output path (Vdc; Idc) to the device-side control circuit through the data signal (DATA), the device-side control circuit is arranged to operably calculate a difference between the charger-side voltage value and the device-side voltage value to generate a voltage drop estimation value of the charging cable; wherein the device-side control circuit is further arranged to operably generate a corresponding adjustment instruction based on the voltage drop estimation value, and to operably transmit the adjustment instruction to the mobile charger (102; 902) through the data signal (DATA) to instruct the mobile charger (102; 902) to control the power converting circuit to maintain the output voltage signal (Vout) and the output current signal (Iout) supplied to the mobile device in a safe range by adjusting the magnitude of at least one of the DC current signal (Idc) and the DC voltage signal (Vdc) so as to control a voltage drop of the charging cable to be less than a predetermined threshold.