Already in 2003, eight double decker hotel trains of the type City Night Line have been equipped with the multi-voltage auxiliary power supply system MEE-NTLD developed by SMA. In spring 2009, further 5 double decker hotel trains of the German Rail daughter DB Autozug will be provided with SMA technology. The multi-voltage auxiliary power supply system MEE-NTLD operates at a power of 75 kVA and comprises a high-voltage inverter, a battery charger, that charges the wagon battery, and two three-phase converters, that supply the electrical consumers and the air conditioning system in the coach. The conversion of the coaches is realized in the Neumünster plant of the German Rail (DB).