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List of Battery Sizes

A battery size is a standardized physical format — the case, the terminals, and the nominal voltage — independent of what chemistry fills it. The international standard IEC 60086 names each format with a chemistry letter (L alkaline, S silver-oxide, C lithium, P zinc-air), an R for round, and a size code, so the same AA case is an LR6 as an alkaline, an R6 as a zinc-carbon, and an FR6 as a lithium cell; ANSI publishes parallel American numbers such as 15A.

The table runs family by family: the cylindrical 1.5-volt cells from AAAA up to D, the little 12-volt A23 and A27, the rectangular and multi-cell blocks led by the nine-volt, button and coin cells from the LR41 to the CR2450, photo lithium, the rechargeable lithium-ion sizes whose names encode their dimensions (an 18650 is 18 mm across and 65 mm long), and the four color-coded zinc-air hearing-aid sizes. The A, A23, and A27 cells also appear in the encyclopedia’s A band.

Cylindrical cells

AAAA	Quadruple-A cellSlim 1.5-volt cell, 8.3 × 42.5 mm (IEC LR8D425, ANSI 25A); powers styluses, laser pointers, and glucose meters, and six of them stack inside some nine-volt batteries.
AAA	Triple-A cell1.5-volt cell, 10.5 × 44.5 mm (alkaline LR03, zinc-carbon R03, lithium FR03; ANSI 24A); the standard size for remote controls and other low-drain devices.
AA	Double-A cell1.5-volt cell, 14.5 × 50.5 mm (alkaline LR6, zinc-carbon R6, lithium FR6; ANSI 15A); the most widely used household battery size in the world.
A	A cellUncommon 1.5-volt cell, 17 × 50 mm; rarely sold at retail on its own, but formerly common inside laptop and other assembled battery packs.
B	B cell1.5-volt cell, 21.5 × 60 mm; now rare in consumer devices, surviving mainly inside some European lantern batteries.
C	C cell1.5-volt cell, 26.2 × 50 mm (alkaline LR14, zinc-carbon R14; ANSI 14A); a medium-drain size for flashlights, toys, and portable audio.
D	D cellThe largest common cylindrical 1.5-volt cell, 34.2 × 61.5 mm (alkaline LR20, zinc-carbon R20; ANSI 13A); standardized in the 1920s and descended from the earliest flashlight cells.
F	F cellTall 1.5-volt cell, about 33 × 91 mm; almost never sold alone — four of them typically sit inside a six-volt lantern battery.
N	N cellShort 1.5-volt cell, 12 × 30.2 mm (alkaline LR1; ANSI 910A); used in small flashlights, instruments, and some remote transmitters.
A23	A23 batteryCompact 12-volt alkaline cylinder, about 10.3 × 28.5 mm (8LR932, MN21) — internally a stack of eight 1.5-volt cells; standard in keyless-entry remotes and wireless doorbells.
A27	A27 batterySlim 12-volt alkaline cylinder, about 8 × 28.2 mm (8LR732, MN27), a thinner sibling of the A23; used in small remote controls and security transmitters.

Rectangular & multi-cell batteries

9V	Nine-volt battery (PP3)Rectangular nine-volt block, roughly 48.5 × 26.5 × 17.5 mm, with two snap terminals (6LR61; ANSI 1604A) — internally six 1.5-volt cells in series; the classic smoke-alarm battery.
3LR12	4.5-volt flat packFlat 4.5-volt battery of three cells with two brass strip terminals; a mainly European format, historically common in pocket flashlights.
4LR25	Six-volt lantern batteryLarge six-volt block of four cells with spring or screw terminals; powers lanterns and other high-drain portable lights.

Button & coin cells

LR41	Alkaline button cell (AG3)1.5-volt alkaline button, 7.9 × 3.6 mm (also sold as AG3 or 192; the silver-oxide twin is SR41/392); used in small thermometers, watches, and laser pointers.
LR44	Alkaline button cell (AG13)1.5-volt alkaline button, 11.6 × 5.4 mm (also AG13, A76, or LR1154); one of the most common button cells, used in calculators, toys, and thermometers.
SR44	Silver-oxide button cell (357)1.55-volt silver-oxide twin of the LR44 in the same 11.6 × 5.4 mm case (also 357 or 303); a flatter discharge curve and higher capacity make it the choice for watches.
CR2016	20 mm lithium coin cell, 1.6 mmThree-volt lithium coin cell, 20 mm across and 1.6 mm thick — the thinnest of the common 20-millimeter coins; used in key fobs and slim electronics.
CR2025	20 mm lithium coin cell, 2.5 mmThree-volt lithium coin cell, 20 × 2.5 mm, the middle thickness between the CR2016 and CR2032; common in car keys and small scales.
CR2032	20 mm lithium coin cell, 3.2 mmThree-volt lithium coin cell, 20 × 3.2 mm — the most widely used coin cell, powering motherboard clocks, car keys, and fitness trackers; the digits encode the size (20 mm diameter, 3.2 mm height).
CR2450	24.5 mm lithium coin cellLarge three-volt lithium coin cell, 24.5 × 5.0 mm, with several times the capacity of a CR2032; used in LED candles, sensors, and medical wearables.

Photo lithium cells

CR123A	Photo lithium cellStubby three-volt lithium cell, about 17 × 34.5 mm, built for high-drain loads; a staple of cameras, tactical flashlights, and security sensors.
CR2	Photo lithium cell (CR2)Compact three-volt lithium cell, about 15.6 × 27 mm, shorter than the CR123A; used in film cameras, rangefinders, and some sensors.

Rechargeable lithium-ion cells

14500	AA-size lithium-ion cellRechargeable lithium-ion cylinder, 14 × 50 mm — the same case as an AA but a nominal 3.6–3.7 volts, so the two are not interchangeable unless a device explicitly supports both.
18650	18 mm lithium-ion cellThe workhorse rechargeable lithium-ion cylinder, 18 × 65 mm at a nominal 3.6–3.7 volts, produced by the billions for laptops, power tools, e-bikes, and electric cars; the name encodes the size (18 mm diameter, 65 mm length).
21700	21 mm lithium-ion cellNewer, larger rechargeable lithium-ion cylinder, 21 × 70 mm, holding roughly a third more energy than an 18650; increasingly the standard cell in electric vehicles and premium flashlights.

Zinc-air hearing-aid batteries

10	Size 10 hearing-aid batterySmallest standard 1.4-volt zinc-air hearing-aid cell, 5.8 × 3.6 mm, marked by a yellow tab; fits completely-in-canal and other tiny aids. Pulling the tab lets air reach the cell and activates it.
13	Size 13 hearing-aid battery1.4-volt zinc-air hearing-aid cell, 7.9 × 5.4 mm, marked by an orange tab; a common size for behind-the-ear aids.
312	Size 312 hearing-aid batteryThe most commonly used hearing-aid size in the United States — a 1.4-volt zinc-air cell, 7.9 × 3.6 mm, marked by a brown tab (IEC PR41); fits receiver-in-canal and mini behind-the-ear aids.
675	Size 675 hearing-aid batteryLargest standard 1.4-volt zinc-air hearing-aid cell, 11.6 × 5.4 mm, marked by a blue tab (IEC PR44); powers high-power behind-the-ear aids and cochlear-implant processors.

The standard battery sizes side by side — cylindrical cells from AAAA to D, the nine-volt block, button and coin cells, photo lithium, 18650 and 21700 lithium-ion, and zinc-air hearing-aid batteries

Frequently asked questions

What is the most common battery size?

The AA (IEC LR6 in its alkaline form) is the most widely used household battery size in the world, followed by the AAA. Both are nominal 1.5-volt cylindrical cells; the AA measures 14.5 × 50.5 mm.

What do the letters in LR6 or CR2032 mean?

The IEC code reads chemistry first, then shape, then size: L is alkaline, S silver-oxide, C lithium, and P zinc-air, while R means round. A four-digit size code gives the dimensions — CR2032 is a lithium round cell 20 mm across and 3.2 mm high.

What size battery do hearing aids use?

Four standardized zinc-air sizes, identified by the color of the pull tab: size 10 (yellow), 13 (orange), 312 (brown), and 675 (blue). All are nominal 1.4-volt cells, and size 312 is the most commonly used in the United States.

Why is the small A23 battery 12 volts?

Because it is not a single cell — inside the 28.5 mm cylinder is a stack of eight 1.5-volt button cells in series, giving 12 volts for keyless-entry remotes and doorbells. Its slimmer sibling, the A27, is built the same way.

Can a 14500 lithium-ion cell replace an AA?

Only if the device explicitly supports it. A 14500 has the same 14 × 50 mm case as an AA but delivers a nominal 3.6–3.7 volts instead of 1.5 — more than double — which can destroy electronics designed for AA cells.

What does 18650 mean on a battery?

It encodes the dimensions: an 18650 is a cylindrical cell 18 mm in diameter and 65 mm long. It is the workhorse rechargeable lithium-ion size, used in laptops, power tools, e-bikes, and electric cars; the newer 21700 (21 × 70 mm) holds roughly a third more energy.