A battery module including a row of batteries; and end plates coupled to ends of the row of batteries, wherein the end plates include a reinforcing portion for increasing strength of the end plates. The method determines a regenerative torque capacity, calculates a desired regenerative torque amount for the braking system, detects that the desired regenerative torque amount exceeds the regenerative torque capacity by at least a threshold amount, and controls actuation of the friction braking system in response to the detecting. Use of the security chip protects against offline attacks. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units. This offers the advantage that relevant X-ray examination apparatus may have a simple construction, that the electronic components used in the construction have a correspondingly prolonged service life due to the constant low temperature, and that the apparatus can operate with a higher mean power as a result of the cooling. The retrievable valve assembly includes a rotary valve member having one or more primary flow ports.