Abstract: A battery system comprises at least one battery module and a docking station on which the at least one battery module is arranged in a separately removable manner. Preferably, the docking station comprises supply and/or power connections for the battery system.

Abstract: A hand-power tool includes at least one tool spindle and a drive unit configured to drive the tool spindle at a rotational speed greater than 10,000 min?1. The drive unit has a brushless electric motor.

Abstract: A method for operating a wave energy converter for converting energy from a wave motion of a fluid into a different form of energy includes at least one rotor and at least one energy converter that is coupled to the at least one rotor. A first torque that acts on the at least one rotor is generated by the wave motion, and a second torque (M1) that acts on the at least one rotor is generated by the at least one energy converter. The second torque (M1) is specified during a control of the energy converter.

Abstract: A seal between an outer part and a circular cylindrical inner part, which is accommodated within the outer part at least in sections, includes a sealing ring having a groove portion and consisting of high-temperature-resistant thermoplastic plastics material. The outer part and the inner part are movable in a linear manner in relation to each other. A circumferential groove, into which the groove portion of the sealing ring is inserted at least in sections, is realized on an inner circumference of the outer part or on an outer circumference of the inner part. The sealing ring is in one part, and the groove is closed.