A protection circuit (1A, 1B) for protecting a battery pack having rechargeable batteries (6-1, 6-2,...) connected in series from overcurrents and overvoltages, the protection circuit (1A, 1B) comprising: a protection device having a heating resistor and a fuse element provided on a circuit board; a plurality of sensing means for sensing an overvoltage between different batteries in the battery pack, each sensing means being configured to detect an overvoltage across any of its sensed batteries and to switch a current flowing into the heating resistor; and a first FET configured to flow a current through drain - source of the first FET, when the voltage at its gate is above a first predetermined voltage, thereby causing the current flowing into the heating resistor to be switched on, wherein the fuse element is configured to be melted in an overcurrent condition, and each sensing means is configured to switch on the current flowing into the heating resistor in an overvoltage condition on any of its sensed batteries, thereby causing the heating resistor to generate heat and the fuse element to be melted, a first sensing means includes a first voltage sensing IC, wherein the first voltage sensing IC is configured to sense a voltage across a predetermined number out of the batteries in the battery pack and each individual battery of said predetermined number out of the batteries in the battery pack, and to output the sensed voltage to the gate of the first FET, a second sensing means includes a second voltage sensing IC, wherein the second voltage sensing IC is configured to sense a voltage across a predetermined number out of the batteries in the battery pack and each individual battery of said predetermined number out of the batteries in the battery pack, and to output the sensed voltage to a gate of a second FET, thereby causing the voltage at the gate of the first FET to raise above the first predetermined voltage. the protection circuit (1A, 1B) comprising: a protection device having a heating resistor and a fuse element provided on a circuit board; a plurality of sensing means for sensing an overvoltage between different batteries in the battery pack, each sensing means being configured to detect an overvoltage across any of its sensed batteries and to switch a current flowing into the heating resistor; and a first FET configured to flow a current through drain - source of the first FET, when the voltage at its gate is above a first predetermined voltage, thereby causing the current flowing into the heating resistor to be switched on, wherein a protection device having a heating resistor and a fuse element provided on a circuit board; a plurality of sensing means for sensing an overvoltage between different batteries in the battery pack, each sensing means being configured to detect an overvoltage across any of its sensed batteries and to switch a current flowing into the heating resistor; and a first FET configured to flow a current through drain - source of the first FET, when the voltage at its gate is above a first predetermined voltage, thereby causing the current flowing into the heating resistor to be switched on, wherein the fuse element is configured to be melted in an overcurrent condition, and each sensing means is configured to switch on the current flowing into the heating resistor in an overvoltage condition on any of its sensed batteries, thereby causing the heating resistor to generate heat and the fuse element to be melted, a first sensing means includes a first voltage sensing IC, wherein the first voltage sensing IC is configured to sense a voltage across a predetermined number out of the batteries in the battery pack and each individual battery of said predetermined number out of the batteries in the battery pack, and to output the sensed voltage to the gate of the first FET, a second sensing means includes a second voltage sensing IC, wherein the second voltage sensing IC is configured to sense a voltage across a predetermined number out of the batteries in the battery pack and each individual battery of said predetermined number out of the batteries in the battery pack, and to output the sensed voltage to a gate of a second FET, thereby causing the voltage at the gate of the first FET to raise above the first predetermined voltage.