IEC 60086-1:2015 RLV contains both the official IEC International Standard and its Redline version. The Redline version is available in English only and provides you with a quick and easy way to compare all the changes between the official IEC Standard and its previous edition. IEC 60086-1:2015 is intended to standardize primary batteries with respect to dimensions, nomenclature, terminal configurations, markings, test methods, typical performance, safety and environmental aspects. As a primary battery classification tool, electrochemical systems are also standardized with respect to system letter, electrodes, electrolyte, nominal and maximum open circuit voltage. The object of this part of IEC 60086 is to benefit primary battery users, device designers and battery manufacturers by ensuring that batteries from different manufacturers are interchangeable according to standard form, fit and function. Furthermore, to ensure compliance with the above, this part specifies standard test methods for testing primary cells and batteries. This twelfth edition cancels and replaces the eleventh edition (2011) and constitutes a technical revision. The major technical changes with respect to the previous edition are: - the order of the Annexes was changed to the order in which they appear in the document and a caption was added to indicate where the Annex information first appears in the document; - the humidity conditions for non P-system batteries in Table 3 was modified; - the standard discharge voltage for the Y and W chemistries was determined to be at 3,5 V and 2,8 V respectively; - details on capacity measurement were moved from Annex E to Subclause 5.1. - the coin/button cell and battery definition was clarified in order to better address issues with the swallowing of coin cells. Keywords: fundamental requirements and information on primary cells and batteries