Abstract: To make a battery pack (2) capable of connection over a communication network for the sake of maintenance of the battery pack (2). The battery pack (2) is provided with a network interface (12) given a unique IP address, which is connected to a LAN along with a network interface (11) of a PC body (1). Even if the PC body (1) is suspended, the battery pack (2) can be accessed over the LAN. A computer for maintenance, arranged on the LAN, can thus access the battery back (2) to acquire the operating status of a rechargeable battery (3) and data stored in a memory (8), such as a serial number, thereby performing maintenance.

Abstract: Firmware of a battery pack (2) is stored in a rewritable storage device such as a flash memory (8). When troubleshooting or performance improvement is needed, a personal computer main body (host equipment) (1) obtains up-to-date firmware from a storage medium or the Internet, and transmits it to a battery pack (2) via an SMBus (5) using a firmware transfer device (12). A firmware rewriting device (11) of the battery pack (2) rewrites the firmware stored in the flash memory (8) on the basis of the up-to-date firmware.

Abstract: To make a battery pack (2) capable of connection over a communication network for the sake of maintenance of the battery pack (2). The battery pack (2) is provided with a network interface (12) given a unique IP address, which is connected to a LAN along with a network interface (11) of a PC body (1). Even if the PC body (1) is suspended, the battery pack (2) can be accessed over the LAN. A computer for maintenance, arranged on the LAN, can thus access the battery back (2) to acquire the operating status of a rechargeable battery (3) and data stored in a memory (8), such as a serial number, thereby performing maintenance.

Abstract: Firmware of a battery pack (2) is stored in a rewritable storage device such as a flash memory (8). When troubleshooting or performance improvement is needed, a personal computer main body (host equipment) (1) obtains up-to-date firmware from a storage medium or the Internet, and transmits it to a battery pack (2) via an SMBus (5) using a firmware transfer device (12). A firmware rewriting device (11) of the battery pack (2) rewrites the firmware stored in the flash memory (8) on the basis of the up-to-date firmware.