Abstract: A modification to existing mono-block battery design for positively indicating the operating condition of the battery. The voltage of two groups of internal series connected cells are measured and compared. An indicator of one color indicates the battery is operating normally, an indicator of a contrasting color indicates the battery is defective.

Abstract: When a charging control computer energized by an auxiliary battery detects a failure of an external AC power supply based on a change in the level of a failure on/off signal while a battery, mounted as an energy source on an electric vehicle, is being charged by the external AC power supply, the charging control computer stores a charged time up to the failure of the external AC power supply. Then, the charging control computer immediately changes from a normal power consumption mode to a low power consumption mode. When the charging control computer subsequently detects when the external AC power supply recovers from the failure, the charging control computer calculates a new target charging time from an initial target charging time and the charged time. Wasteful power consumption by the auxiliary battery during the failure of the external AC power supply is minimized.

Abstract: A safety device for a portable battery-powered electric apparatus having a battery unit with one or more battery cells for supplying power to electric circuitry in the apparatus. The apparatus is connectable to a charging device for charging the battery unit while maintaining the supply of power to the apparatus. The safety device has a first fuse device connected between the battery unit and a first terminal of the apparatus for receiving charging current from the charging device, and a second fuse device connected between the battery unit and a second terminal of the apparatus for supplying power to electric circuitry in the apparatus. The fuse devices are operatively independent of each other, particularly in that the second fuse device maintains the electric connection between the battery unit and the electric circuitry in the apparatus, even when or if the first fuse device releases or opens in response to an undesired condition in the charging device.