Applies to direct current (d.c.) powered mobile equipment. The equipment is operated while being transported, for example in or on a vehicle but does not form part of the vehicle, and is not designed to be installed permanently in a vehicle. The equipment experiences general open-air climates according to IEC 60721-2-1. The degree of simulation of this test cycle is low. The contents of the corrigendum of March 1996 have been included in this copy.