Patent attributes
A rechargeable battery pack attachable to a power tool includes a display element, a remaining capacity detection device, a remaining capacity display control device, an abnormality detection device, and an abnormality display control device. The display element is provided such that a lighted state thereof can be confirmed from outside. The remaining capacity detection device detects a remaining capacity of a rechargeable battery. The remaining capacity display control device displays the remaining capacity detected by the remaining capacity detection device by controlling the lighted state of the display element. The abnormality detection device detects an abnormality of the rechargeable battery. The abnormality display control device displays the abnormality of the rechargeable battery detected by the abnormality detection device by controlling the lighted state of the display element to an abnormality display state, which is different from a remaining capacity display state controlled by the remaining capacity display control device.
