An aircraft including a battery pack having a plurality of battery cells arranged to vent into a venting region of the battery pack. A path is defined between the venting region and an exterior of the aircraft, whereby thermal products vented by the cells can exit the aircraft via the path. In some embodiments, the venting region is or is in fluid communication with an air channel through which air flows from an aircraft air inlet to an aircraft air outlet. In other embodiments, the path joins the venting region and an opening in an external surface of the aircraft.