The letters give the chemistry and the shape, and on coin and button cells the numbers give the size. A CR2032 is a round lithium cell, 20 mm across and 3.2 mm thick.
Printed on the flat side of a coin or button cell, or on the label of a larger battery.
What the code means
The first letter: the chemistry
GP’s guide gives two letters in its own words: “The C means lithium primary”, and “the L stands for alkaline”.
| Letter | On the sheet | Sheet |
|---|---|---|
| C | CR2032, lithium manganese dioxide, 3 V | Energizer and Panasonic CR2032 |
| L | LR44, alkaline, 1.5 V | Energizer A76 |
| S | SR44, silver oxide, 1.55 V | Energizer 357 |
| B | BR2032, Panasonic’s BR series lithium, 3 V | Panasonic BR2032 |
| F | FR6, an AA in lithium iron disulfide, 1.5 V | Energizer L91 |
| P | PR44, a 675 zinc air hearing aid cell, 1.4 V | Energizer 675 |
| H | HR22, a rechargeable nickel metal hydride 9V, 8.4 V | Energizer NH22-175 |
The R and the numbers
GP’s guide to coin cells says the R means a round shape. On a CR coin cell the numbers are the size: in GP’s words, 2032 means a diameter of 20 mm and a thickness of 3.2 mm. Other lengths of number follow the size on their own sheets:
- Four digits: Energizer’s 189 sheet gives the LR54, which GP also lists as LR1130, as 11.6 mm across and 3.05 mm thick. The 11 is the width in whole millimeters, rounded down.
- Three digits: on Renata’s 377 sheet, SR626SW is 6.8 x 2.6 mm. The 6 is the width rounded down, and 26 the thickness in tenths.
- Five digits: on Energizer’s 123 sheet, CR17345 is 17 x 34.5 mm, the width and then the length in tenths.
- One or two digits: on Energizer’s A76 sheet, LR44 is 11.6 x 5.4 mm, and LR6 is the IEC name on its AA sheet. These numbers aren’t millimeters.
The number in front of a code such as 6LR61, the 9V, is part of the IEC name the maker prints.
SW and W at the end
Renata heads its 377 sheet SR626SW and its 376 sheet SR626W: the same 6.8 x 2.6 mm silver oxide size. Its sheets call the SW cells (377, 384, 390) low drain and the W cells (376, 392, 389) high drain. Energizer’s silver oxide manual says low drain cells are for steady use over years, as in analog watches, and high drain ones for watches with a backlight or alarm and for calculators.
CR or BR
Panasonic makes both a CR2032 and a BR2032, each 3 V and 20 x 3.2 mm. Its CR2032 is rated 225 mAh at a 0.2 mA drain, works from -30 to 85°C and has, in Panasonic’s words, “excellent low-temperature performance”. Its BR2032 is rated 200 mAh at 0.03 mA, works from -40 to 85°C and is “primarily used for memory-backup power in low-drain applications”. Fit the letter your device names.
Numbers that aren’t IEC codes
Watch numbers such as 377 and 357, makers’ product numbers such as A76 and MN21, and ANSI numbers such as 1604A name a cell without spelling out its chemistry or size. The battery equivalent finder ties each one to the cell its makers give it.
If a battery is swallowed
If anyone may have swallowed a coin or button battery, don’t delay: call the 24-hour National Battery Ingestion Hotline at 1-800-498-8666 or your poison center at 1-800-222-1222.