Patent ID: 8390243

Claim:
A charge-controlling system applicable to a backup power system, the backup power system having a fuel-cell-based power supply and a regulated battery that serves to stabilize a power output of the backup power system, and the charge-controlling system comprising: a bidirectional converter electrically connected between the fuel-cell-based power supply and the regulated battery; a feedback circuit configured to generate a feedback signal corresponding to an output voltage of the bidirectional converter; a voltage controller electrically connected to the feedback circuit and configured to generate a control voltage according to the feedback signal and a constant voltage; a pulse-width-modulation generator electrically connected the voltage controller and configured to generate a PWM signal according to the control voltage; a switch unit electrically connected between the bidirectional converter and the pulse-width-modulation generator, wherein when the switch unit turns on the bidirectional converter and the pulse-width-modulation generator, the bidirectional converter, according to the PWM signal, charges the regulated battery with power generated by the fuel-cell-based power supply; and an over-charging protection circuit electrically connected between the feedback circuit and the switch unit and configured to control the switch unit according to the feedback signal and a saturation voltage of the regulated battery.