Abstract: A battery power supply system and a battery power supply method for a main system are provided. The battery power supply system includes a power supply processor, an expansion slot module with plural slots, and plural battery units. The plural battery units are docked with the corresponding slots. Moreover, plural control switches are electrically connected between the corresponding slots and the power supply processor. A voltage value of one battery unit is defined as a fiducial voltage value. If the difference between the fiducial voltage value and the voltage value of at least one battery unit of the rest of the battery units is within a predetermined value, the control switch corresponding to the at least one battery unit is turned on. The battery unit with the fiducial voltage value and the at least one battery unit are connected with each other in parallel.

Abstract: A battery power supply system and a battery power supply method for a main system are provided. The battery power supply system includes a power supply processor, an expansion slot module with plural slots, and plural battery units. The plural battery units are docked with the corresponding slots. Moreover, plural control switches are electrically connected between the corresponding slots and the power supply processor. A voltage value of one battery unit is defined as a fiducial voltage value. If the difference between the fiducial voltage value and the voltage value of at least one battery unit of the rest of the battery units is within a predetermined value, the control switch corresponding to the at least one battery unit is turned on. The battery unit with the fiducial voltage value and the at least one battery unit are connected with each other in parallel.

Abstract: A dual screen point-of-sale system includes a point-of-sale device and a tablet computer. The point-of-sale device includes a first display screen and a first connection part. A first picture of the point-of-sale device is shown on the first display screen in response to a first device signal. The first connection part receives the first device signal. The tablet computer includes a second connection part and a second display screen. When the first connection part and the first connection part are in communication with each other, the first device signal is transmitted from the point-of-sale device to the tablet computer. Consequently, a picture corresponding to the first device signal is shown on the second display screen. When the first connection part and the first connection part are not in communication with each other, a second picture is shown on the second display screen.

Abstract: A dual screen point-of-sale system includes a point-of-sale device and a tablet computer. The point-of-sale device includes a first display screen and a first connection part. A first picture of the point-of-sale device is shown on the first display screen in response to a first device signal. The first connection part receives the first device signal. The tablet computer includes a second connection part and a second display screen. When the first connection part and the first connection part are in communication with each other, the first device signal is transmitted from the point-of-sale device to the tablet computer. Consequently, a picture corresponding to the first device signal is shown on the second display screen. When the first connection part and the first connection part are not in communication with each other, a second picture is shown on the second display screen.