Battery nomenclature

Standard battery nomenclature describes portable dry cell batteries that have physical dimensions and electrical characteristics interchangeable between manufacturers. The long history of disposable dry cells means that many manufacturer-specific and national standards were used to designate sizes, long before international standards were reached. Technical standards for battery sizes and types are set by standards organizations such as International Electrotechnical Commission and American National Standards Institute. Popular sizes are still referred to by old standard or manufacturer designations, and some non-systematic designations have been included in current international standards due to wide use.
The complete nomenclature for the battery will fully specify the size, chemistry, terminal arrangements, and special characteristics of a battery. The same physically interchangeable cell size may have widely different characteristics; physical interchangeability is not the sole factor in substitution of batteries.
National standards for dry cell batteries have been developed by ANSI, JIS, British national standards, and others. Civilian, commercial, government, and military standards all exist. Two of the most prevalent standards currently in use are the IEC 60086 series and the ANSI C18.1 series. Both standards give dimensions, standard performance characteristics, and safety information.
Modern standards contain both systematic names for cell types that give information on the composition and approximate size of the cells, as well as arbitrary numeric codes for cell size.

History of the IEC standard

The International Electrotechnical Commission was established in France in 1906 and co-ordinates development of standards for a wide range of electrical products. The IEC maintains two committees, TC21 established in 1933 for rechargeable batteries, and TC35 established in 1948 for primary batteries, to develop standards. The current designation system was adopted in 1992. Battery types are designated with a letter/number sequence indicating number of cells, cell chemistry, cell shape, dimensions, and special characteristics. Certain cell designations from earlier revisions of the standard have been retained.
The first IEC standards for battery sizes were issued in 1957.
Since 1992, International standard IEC 60086 defines an alphanumeric coding system for batteries.
British standard 397 for primary batteries was withdrawn and replaced by the IEC standard in 1996.

History of the ANSI standard

Standardization of batteries in the United States started in 1919, when the US National Bureau of Standards published recommended test procedures and standard dimensions of cells. American standards were revised several times during the following decades, as new sizes of cells were introduced and new chemistry developed, including chloride, alkaline, mercury and rechargeable types.
The first American Standards Association standard C18 appeared in 1928. It listed cell sizes using a letter code, roughly in order of size from smallest to larger types. The only numerical designation was the 6-inch tall "No. 6" cell. The older "No. 1" through "No. 5" batteries were discontinued, each being 1 to 5 inches high respectively, although the similarly sized Burgess No. 1 and No. 2 were still produced under that name through the 1950s. Eventually, the No. 6 was phased out by the 1970s and slowly replaced with the 6-volt four-cell battery. The 1934 edition of the C18 standard expanded the nomenclature system to include series and parallel arrays of cells. In 1954, mercury batteries were included in the standard. The 1959 edition identified types suitable for use with transistor radios. In 1967, NEMA took over responsibility for development from the National Bureau of Standards. The 12th edition of C18 began to be harmonized with the IEC standard. Rechargeable batteries were introduced in the C18 standard in 1984, and lithium types were standardized in 1991.
In 1999 the ANSI standards were extensively revised and separate safety standards provided. The current edition of the ANSI standards designates sizes with an arbitrary number, with a prefix letter to designate shape, and with a suffix letter or letters to identify different chemistry, terminals, or other features.

IEC battery nomenclature

Three different technical committees of IEC make standards on batteries: TC21, SC21 and TC35. Each group has published standards relating to the nomenclature of batteries - IEC 60095 for lead-acid starter batteries, IEC 61951-1 and 61951-2 for Ni-Cd and Ni-MH batteries, IEC 61960 for Li-ion, and IEC 60086-1 for primary batteries.

Primary batteries

Battery numbering

Examples of the IEC nomenclature are batteries coded R20, 4R25X, 4LR25-2, 6F22, 6P222/162, CR17345 and LR2616J. The letters and numbers in the code indicate the number of cells, cell chemistry, shape, dimensions, the number of parallel paths in the assembled battery and any modifying letters deemed necessary. A multi-section battery will have a multi-section designation.
Prior to October 1990, round cells were designated with a sequential numeric size code ranging from R06 through to R70; for example, R20 is the size of a "D" cell or ANSI"13" size. After October 1990, round cells became systematically identified with a number derived from their diameter and height. Primary cells larger than 100 mm in diameter or height are designated with an oblique "/" between diameter and height.

Designation	Series Cells	System	Shape	Standardized code or diameter code	Diameter modifier	Height code	Height adjustment modifier	Modifier	Parallel strings	Remarks
R20			R	20						A single zinc-carbon cell, "size 20" which is equivalent to D, or ANSI "13" size
4R25X	4		R	25				X		A zinc-carbon lantern battery, consisting of 4 round "size 25" cells in series. Terminated with spring terminals.
4LR25-2	4	L	R	25					2	An alkaline lantern battery, consisting of 2 parallel strings of 4 round "size 25" cells in series
6F22	6		F	22						A zinc-carbon rectangular battery, consisting of 6 flat "size 22" cells. Equivalent to a PP3 or transistor battery.
6P222/162	6		P	222		162				A zinc-carbon battery, maximum dimensions: length 192 mm, width 113 mm, and height 162 mm. Consisting of 6 cells in series.
CR17345		C	R	17		345				A single-cell round lithium cell, 17 mm diameter, 34.5 mm height
LR2616J		L	R	26		16	J			A single-cell round alkaline battery, 26.2 mm diameter, 1.67 mm height
LR8D425		L	R	8.5	D	425				A single-cell round alkaline battery, 8.8 mm diameter and 42.5 mm long, AAAA or ANSI "25" size

Electrochemical system

The first letter identifies the chemical composition of the battery, which also implies a nominal voltage.
It is common to refer to the negative electrode first in IEC battery definitions.

Letter code	Negative electrode	Electrolyte	Positive electrode	Nominal voltage	Maximum open circuit voltage	Main article
	Zinc	Ammonium chloride, Zinc chloride	Manganese dioxide	1.5	1.725	Zinc-carbon battery
A	Zinc	Ammonium chloride, Zinc chloride	Oxygen	1.4	1.55	Zinc-air battery
B	Lithium	Organic electrolyte	Carbon monofluoride	3.0	3.7	Lithium battery
C	Lithium	Organic electrolyte	Manganese dioxide	3.0	3.7	Lithium battery
E	Lithium	Non-aqueous inorganic electrolyte	Thionyl chloride	3.6	3.9	Lithium battery
F	Lithium	Organic electrolyte	Iron disulfide	1.5	1.83	Lithium battery
G	Lithium	Organic electrolyte	Copper oxide	1.5	2.3	Lithium battery
L	Zinc	Alkali metal hydroxide	Manganese dioxide	1.5	1.65	Alkaline battery
M	Zinc	Alkali metal hydroxide	Mercuric oxide	1.35		Mercury battery
N	Zinc	Alkali metal hydroxide	Mercuric oxide, manganese dioxide	1.4		Mercury battery
P	Zinc	Alkali metal hydroxide	Oxygen	1.4	1.68	Zinc-air battery
S	Zinc	Alkali metal hydroxide	Silver oxide	1.55	1.63	Silver-oxide battery
Z	Zinc	Alkali metal hydroxide	Manganese dioxide, nickel oxyhydroxide	1.5	1.78	Nickel oxyhydroxide battery

Italics indicate a chemical system unlikely to be found in consumer or general-purpose batteries, or withdrawn from the current standard.