Abstract: Disclosed is a battery assembly, comprising a battery box, comprising a housing including a base plate and a cover; at least one battery cell stack mounted inside the housing, wherein each battery cell stack comprises a plurality of battery cells stacked on top of the base plate along a stacking direction and electrically connected in series or in parallel; electrical connectors disposed on the outer side of the housing; and an interface unit for coupling with an electronics unit; and an electronics unit, comprising electronic control components; and an interface unit for coupling with the battery box; wherein in use the battery box and the electronics unit are interfaced by their such respective interface units such that operation of the at least one battery cell stack is controlled by the electronic control components of the electronics unit. Furthermore, the invention relates to an electrical propulsion VTOL aircraft comprising such a battery assembly.

Abstract: An emergency power supply for an electrical device that provides power sufficient to operate the emergency flotation system for a predetermined period of time after a malfunction of a primary power source. The emergency power supply includes at least one capacitor and a control circuit that are disposed in a housing that is sealed to prevent ingress of liquids. The emergency power supply remains functional even when it is partially submerged.