A motor vehicle key of flat structure includes a circuit board with an opening, a mounting for a battery, wherein the mounting extends at least partially over the opening, and contact elements, which are electrically coupled to the circuit board. One contact element includes a resilient contact section, by means of which the battery may be fixed in the position in the mounting. The contact element is fastened to the circuit board such that a region of the resilient contact section extends over the opening above a plane defined by the surface of the circuit board and at least this region is received in the opening when the battery is disposed in the mounting and is fixed in position in it by the resilient contact section.

Embodiments provide an Energy Reduction Maintenance Setting (ERMS) key that includes a data connector configured to communicatively couple to a data port of a target device. The ERMS key further includes an illumination device and an actuator mechanism having a base positional state and an actuated positional state. The ERMS key includes logic configured to, upon detecting the actuator mechanism has moved from the base positional state to the actuated positional state, generate and transmit a first data message to the target device through the data connector instructing the target device to enter a protected mode. The logic is further configured to, upon receiving a second data message from the target device over the data connector acknowledging that the target device has successfully entered the protected mode, cause the illumination device to illuminate.

The present disclosure relates to a LOTO for an MSD switch, a power battery comprising the LOTO, and a work machinery comprising the power battery. The MSD switch comprises a socket formed with a cavity. The LOTO comprises: a lock bracket which is disposed adjacent to the socket and is provided with a lock hole; a retainer which can be releasably locked with the lock bracket; and an insulating block which is mounted on the retainer. The retainer and the insulating block are configured such that when the retainer is locked to the lock bracket, the insulating block engages in the cavity. The LOTO of the present disclosure features simple structure and assembly, low cost and high versatility.