The invention relates to a storage unit for storing electric energy. The storage unit has at least one energy accumulator, in particular a capacitor or an accumulator, the energy accumulator having at least one positive electric connection and at least one negative electric connection. The energy accumulator is designed to be charged with electric energy via the positive connection and the negative connection and to emit the electric energy via the connections. The storage unit has an electrically conductive contact rail connected to the positive connection and an electrically conductive contact rail connected to the negative connection. The contact rails each have at least one contact element which is moulded on the contact rails, in particular in resilient manner, the contact element having at least two wings. The wings extend with at least one direction component in mutually opposed directions. The wings are connected to the connection, each by means of a welded joint.