‘Primary cells’ or batteries and components having an energy density of 150 Wh/kg or more at 293 K (20 o C) Technical Notes: 1. For the purposes of this control, ‘energy density’ (Wh/kg) is calculated from the nominal voltage multiplied by the nominal capacity in ampere-hours (Ah) divided by the mass in kilograms. If the nominal capacity is not stated, energy density is calculated from the nominal voltage squared then multiplied by the discharge duration in hours divided by the discharge load in ohms and the mass in kilograms. 2. For the purposes of this control, a ‘cell’ is defined as an electrochemical device, which has positive and negative electrodes, an electrolyte, and is a source of electrical energy. It is the basic building block of a battery. 3. For the purposes of this control, a ‘primary cell’ is a ‘cell’ that is not designed to be charged by any other source.