Abstract: There is disclosed herein a protection device (100) for a battery pack, and a battery pack (800) comprising such a protection device (100). The protection device (100) comprises a fuse (102) arranged in a space (103) between electrical conductors (104) and configured to weaken when an 5 overcurrent passes therethrough. According to a beneficial aspect of the present disclosure, the protection device (100) comprises an insulator (106) formed as a resilient member having a biased state and a relaxed state. The insulator (106) is held in the biased state by the fuse (102) and is biased towards the space (103) between the electrical conductors (104) in the biased 10 state.