The invention relates to a battery pack, especially for a hand-held power tool. Said battery pack comprises a battery housing (10) and an electronic unit (16) housed in said battery housing (10). The electronic unit (16) has one or more light sources (18). A first light-guiding element (28) can be inserted into the battery housing (10) and interacts with the at least one light source (18) in such a manner that the light emitted by the at least one light source (18) can be injected into the first light-guiding element (28).