Charging controller

A charging controller connected to one or more secondary cells and detachably connected to a charger or a cell driver, the charging controller comprising:

• a charging amount control circuit detecting a cell voltage of each secondary cell;
• comparing the detected cell voltage with a predetermined target voltage;
• and outputting a charging control signal for instructing the charger to reduce a charging current when the detected cell voltage exceeds the target voltage;
• and
• a protection circuit detecting a cell voltage of each secondary cell;
• comparing the detected cell voltage with a predetermined upper limit voltage higher than the target voltage;
• and cutting off a current path from the charger to the secondary cells when the detected cell voltage exceeds the upper limit voltage,
• wherein the charging amount control circuit operates by using the secondary cells as a power source when a control trigger signal is being inputted from the charger while the secondary cells are charged by the charger.

The charging controller connected to one or more secondary cells and detachably connected to a charger or a cell driver, each of the charger and the cell driver having a control power supply circuit supplying a control power to the charging controller, the charging controller comprising:

• a charging amount control circuit detecting a cell voltage of each secondary cell;
• comparing the detected cell voltage with a predetermined target voltage;
• and outputting a charging control signal for instructing the charger to reduce a charging current when the detected cell voltage exceeds the target voltage;
• a fuse connected between the secondary cells and charging terminal to which the charger is connected and;
• a protection circuit detecting a cell voltage of each secondary cell;
• comparing the detected cell voltage with a predetermined upper limit voltage higher than the target voltage;
• and cutting off a current path from the charger to the secondary cells by melting the fuse when the detected cell voltage exceeds the upper limit voltage,
• a protection power supply switch which is switched on or off to supply or stop supply a power from the secondary cells to the protection circuit;
• and
• a switch control circuit controlling the protection power supply switch to be switched on or off,
• wherein the charging amount control circuit does not operate while the control power is not supplied to the charging controller,
• wherein the switch control circuit executes an intermittent switch-on-operation so that the protection power supply switch is intermittently switched on while the control power is not supplied to the charging controller, and the switch control circuit monitors an output of the protection circuit during the intermittent switch-on operation, terminates the intermittent switch-on operation after the protection circuit starts to generate an output for melting the fuse and moves to a continuous switch-on operation.