Abstract: An electrical apparatus comprising a battery for powering the apparatus, the battery comprising a plurality of elongate battery cells, the elongate battery cells each having cell bodies, and positive and negative electrical connections at a first end of the cells, and the battery cells being electrically connected together at their first ends via said connections; and, a coolant flow system arranged to cause a flow of coolant past the bodies of the battery cells toward the first ends of the battery cells.

Abstract: A unit for installation in a complex product comprising an electric machine requiring an AC power supply. The unit comprises: a housing carrying an AC output; a battery in the housing comprising at least one battery cell; an inverter in the housing, the inverter comprising a plurality of voltage controlled impedances, VCIs, for providing a power supply to the AC output based on energy from the battery; wherein the housing carries a timing signal input configured to receive a timing signal from outside the housing; and wherein the timing signal input is coupled to control the VCIs so that changes in the impedances of the VCIs are synchronised with the timing signal.

Abstract: A unit for installation in a complex product comprising an electric machine requiring an AC power supply. The unit comprises: a housing carrying an AC output; a battery in the housing comprising at least one battery cell; an inverter in the housing, the inverter comprising a plurality of voltage controlled impedances, VCIs, for providing a power supply to the AC output based on energy from the battery; wherein the housing carries a timing signal input configured to receive a timing signal from outside the housing; and wherein the timing signal input is coupled to control the VCIs so that changes in the impedances of the VCIs are synchronised with the timing signal.

Abstract: A screw actuator comprises a sleeve encircling part of an actuator shaft, one of the sleeve and the actuator shaft being rotatable, a drive arrangement for rotating the rotatable one of the sleeve and the actuator shaft, and a friction brake arrangement for applying a braking load to the said rotatable one of the sleeve and the shaft to resist rotation thereof, wherein the drive arrangement is adapted to adjust the axial position of the said rotatable one of the sleeve and the actuator shaft to disengage the friction brake arrangement when the said rotatable one of the sleeve and the actuator shaft is being rotated by the drive arrangement.