Abstract: A method of charging a battery and a system using the same are provided. The method includes: detecting a terminal voltage of a battery; When the terminal voltage is less than a voltage threshold, performing quick charging which includes: calculating a rising rate of the terminal voltage, comparing the rising rate with a rising rate reference value, and controlling the terminal voltage according to the comparison result; and when the terminal voltage is not less than the voltage threshold, performing low current floating charging which includes: intermittently charging the battery by a predetermined floating charging period, calculating a falling rate of the terminal voltage, comparing the falling rate with a falling rate reference value, controlling the terminal voltage according to the comparison result, in a first time duration of the floating charging period, and suspending charging in a second time duration of the floating charging period.

Abstract: The present invention discloses a power supply circuit and a UPS auxiliary power supply system having the same. The power supply circuit comprises a transformer, a primary-side switch unit and a secondary-side switch unit. When the input power supply is powered on, the second switch of the secondary-side switch unit maintains in an off state, the first switch of the primary-side switch unit performs an on-off action, and the input power supply supplies power to the load and the energy storage unit. When the input power supply is powered down, the first switch of the primary-side switch unit maintains in an off state, the second switch of the secondary-side switch unit performs an on-off action, and the energy storage unit supplies power to the load.

Abstract: A method of charging a battery and a system using the same are provided. The method includes: detecting a terminal voltage of a battery; When the terminal voltage is less than a voltage threshold, performing quick charging which includes: calculating a rising rate of the terminal voltage, comparing the rising rate with a rising rate reference value, and controlling the terminal voltage according to the comparison result; and when the terminal voltage is not less than the voltage threshold, performing low current floating charging which includes: intermittently charging the battery by a predetermined floating charging period, calculating a falling rate of the terminal voltage, comparing the falling rate with a falling rate reference value, controlling the terminal voltage according to the comparison result, in a first time duration of the floating charging period, and suspending charging in a second time duration of the floating charging period.

Abstract: The present invention discloses a power supply circuit and a UPS auxiliary power supply system having the same. The power supply circuit comprises a transformer, a primary-side switch unit and a secondary-side switch unit. When the input power supply is powered on, the second switch of the secondary-side switch unit maintains in an off state, the first switch of the primary-side switch unit performs an on-off action, and the input power supply supplies power to the load and the energy storage unit. When the input power supply is powered down, the first switch of the primary-side switch unit maintains in an off state, the second switch of the secondary-side switch unit performs an on-off action, and the energy storage unit supplies power to the load.