BATTERY PACK AND ELECTRICAL DEVICE

摘要

A battery pack designed to be incapable of supplying power to an incompatible electrical tool is provided. Said battery pack (88) has the following: a cell assembly that comprises a plurality of battery cells connected in series and has at least a prescribed battery capacity; a controller that monitors the voltage of each battery cell in the cell assembly and outputs a warning signal if the voltage of at least one of the battery cells has fallen to or below a threshold; and a tool-contacting surface (89) on which a positive terminal (73) and a negative terminal (74) for electrically connecting to an electrical-tool body are formed, as is an S terminal (80) for outputting the warning signal from the controller. This battery pack is provided with the following: a first long protrusion (87) for making it such that the battery pack cannot be attached to an electrical-tool body that has a rated voltage lower than the output voltage of the cell assembly; and a second long protrusion (82) for making it such that the battery pack cannot be attached to an electrical-tool body that is not provided with a terminal via which the warning signal outputted via the S terminal can be inputted.