The disclosed embodiments provide a battery pack that includes a fault-monitoring mechanism for detecting faults in the battery pack and indicating the faults to a user. The battery pack also includes a battery cell and enclosure material that encloses the battery cell. The fault may correspond to penetration of the battery pack, a puncture in the enclosure material, a short circuit within the battery cell, and/or a change in pressure within the battery pack. To detect the fault, the fault-monitoring mechanism may utilize a conductive mechanism, a color-changing mechanism, and/or a sensor mechanism in the battery pack.