List of battery sizes

Standardization

The current IEC standards for portable primary (non-rechargeable) batteries bear the 60086 number. The relevant US standards are the ANSI C18 series, which are developed by a committee of the US National Electrical Manufacturers Association (NEMA).

Both standards have several parts covering general principles, physical specifications and safety. Designations by IEC and ANSI standards do not entirely agree, although harmonization is in progress. Manufacturers further have their own systematic identification of cell types, so cross-reference tables are useful to identify equivalent types from different manufacturers.

Lead-acid automotive starting, lighting and ignition batteries have been standardized according to IEC standard 60095 and in North America by standards published by BCI.

Non-standard brand-specific names

Manufacturers may assign proprietary names and numbers to their batteries, disregarding common, colloquial, IEC, and ANSI naming conventions (see LR44 battery as an example). Often this is done to steer customers towards a specific brand, and away from competing or generic brands, by obfuscating the common name. For example, if a remote control needs a new battery and the battery compartment has the label, "Replace with CX472 type battery," many customers will buy that specific brand, not realizing that this is simply a brand name for a common type of battery. For example, British standard "U" series batteries were often sold under manufacturer prefixes such as "C", "SP", "HP", etc.; Ever Ready sold "U2" (D) batteries as "SP2" (standard-duty zinc carbon) and "HP2" (heavy duty zinc chloride).

On the other hand, with obscure battery types the designation assigned by a specific brand will sometimes become the most common name for that battery type, as other manufacturers copy or modify the name so that customers recognize it.

Battery chemistry

The terminal voltage of a battery cell depends on the chemicals and materials used in its construction, and not on its physical size. For example, primary (non-rechargeable) alkaline batteries have a nominal voltage of 1.5 volts. Rechargeable NiCd (nickel cadmium) and NiMH (nickel metal hydride) typically output 1.25 volts per cell. Devices intended for use with primary batteries may not operate properly with these cells, given the reduction in voltage.

Dry Leclanche (carbon-zinc), alkaline and lithium batteries are the most common modern types. Mercury batteries had stable cell terminal voltages around 1.35 volts. From the late 1940s until the mid-1990s, mercury batteries were made in many consumer and industrial sizes. They are no longer available since careless disposal can release toxic mercury into the environment. They have been replaced by zinc-air batteries, which also produce 1.35 volts.

The full battery designation identifies not only the size, shape and terminal layout of the battery but also the chemistry (and therefore the voltage per cell) and the number of cells in the battery. For example, a CR123 battery is always Li-MnO₂ ('lithium') chemistry, in addition to its unique size.

The following tables give the common battery chemistries for the current common sizes of batteries. See Battery Chemistries for a list of other electrochemical systems.

Physical interchangeability

Cylindrical cells typically have a positive terminal nub at one end, and a flat negative terminal at the other. A cell with a nub on the positive terminal is called a button-top, and a cell without a positive nub is called a flat-top. Two different cells of the same nominal size, e.g. two 18650 cells, may have different diameter buttons if made by different manufacturers, and this can lead to incompatibility with devices. Flat-top cells cannot be used in series without modification or soldering into position, because the flat positive terminal of one cell cannot contact with the next cell's negative terminal. Rarely however, a manufacturer may include tiny bumps on the negative terminal, so flat-tops can be used in series.

It is important to check the battery contacts in a device before attempting to install cells, because some will not work with flat-tops or with button-tops whose buttons are the wrong diameter. Some devices have a small bump or spring where the positive terminal of the cell connects, and this allows the use of either button- or flat-top cells. Other devices have a flat area that can only be contacted by a button-top. To prevent damage if a cell is inserted backwards, some devices have a raised plastic ring around the positive contact. This stops the flat negative end of a cell from connecting accidentally, but also stops the positive end of a flat-top or of a button-top with too large button from connecting.

Cylindrical batteries

These are all round batteries with height greater than their diameter. In zinc-carbon or alkaline types they produce around 1.5 volts per cell when fresh. Other types produce other voltages per cell (as low as 1.2 volts for rechargeable nickel-cadmium, up to around 3 volts for lithium/manganese dioxide). This form has a positive nub terminal at the cap of the cell, and the negative terminal at the bottom of the can; the side of the can is not used as a terminal.

Camera batteries

Digital and film cameras often use specialized primary batteries to produce a compact product. Flashlights and portable electronic devices may also use these types.

Lithium cells

Coin-shaped cells are thin compared to their diameter. Polarity is usually stamped on the metal casing.

The IEC prefix "CR" denotes lithium manganese dioxide chemistry. Since Li-MnO₂ cells produce 3 volts there are no widely available alternative chemistries for a lithium coin battery. The "CR" prefix indicates a round lithium/carbon monofluoride cell. See lithium battery for discussion of the different performance characteristics. One Li-MnO₂ cell can replace two alkaline or silver-oxide cells.

IEC designation numbers indicate the physical dimensions of the cylindrical cell. Cells less than one centimeter in height are assigned four-digit numbers, where the first two digits are the diameter in millimeters, while the last two digits are the height in tenths of millimeters. Taller cells are assigned five-digit numbers, where the first two digits are the diameter in millimeters, followed by the last three digits indicating the height in tenths of millimeters.

All these lithium cells are rated nominally 3 volts (on-load), with open circuit voltage about 3.6 volts. Manufacturers may have their own part numbers for IEC standard size cells. The capacity listed is for a constant resistance discharge down to 2.0 volts per cell.

Silver oxide and alkaline cells

Round button cells have heights less than their diameter. The metal can is the positive terminal, and the cap is the negative terminal.

Button cells are commonly used in electric watches, clocks, and timers. IEC batteries that meet the international IEC 60086-3 standard for watch batteries carry a "W" suffix. Other uses include calculators, laser pointers, toys, LED "blinkies", and novelties.

IEC designation numbers indicate the physical dimensions of the cylindrical cell. Cells less than one centimeter in height are assigned 4-digit numbers, where the first 2 digits are the diameter in millimeters, while the last 2 digits are the height in tenths of millimeters. Taller cells are assigned 5-digit numbers, where the first 2 digits are the diameter in millimeters, followed by the last 3 digits indicating the height in tenths of millimeters.

In the IEC designations, cell types with an "SR" prefix use silver oxide chemistry and provide 1.55 volts, while the "LR" prefix batteries use alkaline chemistry and provide 1.5 volts. Common alternative manufacturer's prefixes for these two types are "SG" for silver oxide and "AG" for alkaline. Since there are no "common" names beyond the AG designation, many vendors use these four designations interchangeably for the same physical sized cell.

The functional differences are that silver oxide batteries typically have 50% greater capacity than alkaline chemistry, relatively slowly declining voltage during discharge compared to alkaline types of the same size, and superior leakage resistance. The ultimate energy capacity of a silver battery may be as much as twice that of an alkaline. Also, a silver cell with a flat discharge characteristic is preferable for devices that need a steady voltage, such as photographic light meters, and devices that will not operate below a certain voltage; for example, some digital calipers, which do not work below 1.38 V.

Alkaline batteries are usually cheaper than silver oxide equivalents. Inexpensive devices are sometimes supplied fitted with alkaline batteries, although they would benefit from the use of silver oxide batteries. Exhausted silver oxide cells are often recycled to recover their precious metal content, whereas depleted alkaline cells are discarded with household trash or recycled, depending on the local practices.

Mercury batteries were formerly commonly made in button sizes for watches, but due to careless disposal and the resulting mercury pollution hazard, they are no longer available. This is also a concern for users of vintage camera equipment, which typically used a mercury button battery in the exposure meter for its very steady voltage characteristic. Substitute non-mercury batteries have been produced to replace certain discontinued mercury batteries, typically by incorporating a miniature voltage regulator to simulate the flat voltage discharge characteristics of the original batteries.

In the following table, sizes are shown for the silver-oxide IEC number; types and capacity are identified as "(L)" for alkaline, "(M)" for mercury (no longer manufactured), and "(S)" for silver-oxide. In some cases, sizes that originally were considered distinct are now interchangeable. For example, the 189/389 cell is 3.1 mm high and was designated 1131, while the 190/390 size is 3.0 mm high and was designated 1130, but these sizes are now considered equivalent.

Zinc air cells (hearing aid)

Miniature zinc-air batteries are button cells that use oxygen in air as a reactant and have very high capacity for their size. Each cell needs around 1 cubic centimetre of air per minute at a 10 mA discharge rate. These cells are commonly used in hearing aids. A sealing tab keeps air out of the cell in storage; a few weeks after breaking the seal the electrolyte will dry out and the battery becomes unusable, regardless of use. Nominal voltage on discharge is 1.2 volts.

Cylindrical lithium-ion rechargeable battery

Lithium-ion rechargeable batteries are generally not interchangeable with primary types using different chemistry, although certain sizes of lithium primary cells do have lithium-ion rechargeable equivalents. Most rechargeable cylindrical cells use a chemistry with a nominal voltage around 3.7 volts, but LiFePO
4 cells produce only 3.2 volts.

Lithium-ion cells are made in various sizes, often assembled into packs for portable equipment. Many types are also available with an internal protection circuit to prevent over-discharge and short-circuit damage. This can increase their physical length; for example, an 18650 is around 65 mm (2.6 in) long, but may be around 68 mm (2.7 in) long with an internal protection circuit. Safe and economic recharging requires use of chargers specified for these cells. Popular applications include laptop battery packs, electronic cigarettes, flashlights, electric vehicles, and cordless power tools.

Commonly-used designation numbers indicate the physical dimensions of the cylindrical cell, in a way similar to the system used for lithium button primary cells. The larger rechargeable cells are typically assigned five-digit numbers, where the first two digits are the (approximate) diameter in millimeters, followed by the last three digits indicating the (approximate) height in tenths of millimeters.

Obsolete batteries

These types are no longer manufactured or only used in legacy applications.

Further information on obsolete batteries may be found on the web sites of the Classic Radio Shop in the UK and the Radiomuseum in Switzerland.

PP series

The PP (Power Pack) series was manufactured by Ever Ready in the UK (Eveready in the US). The series comprised multi-cell carbon-zinc batteries used for portable electronic devices. Most sizes are uncommon today, however the PP3 size (and to a lesser extent PP8 and PP9, which are used in electric fencing and marine applications respectively) is readily available. The PP4 was cylindrical; all the other types were rectangular. Most had snap terminals as seen on the common PP3 type.