Button and coin cells look almost identical across brands, but a code like CR2032 or LR44 tells you the exact chemistry, voltage and dimensions. Reading that code correctly is the difference between ordering the right cell and getting a battery that is the wrong height, voltage or chemistry for the holder. This chart explains the naming system and lists the common button cell battery sizes side by side.
How to read a button cell code
Most codes follow the IEC system: one or two letters for the chemistry, then digits for the size. The first letter is the chemistry — C = lithium manganese dioxide, L = alkaline, S = silver oxide. The R means round. The digits encode the physical size: the first two are the diameter in millimetres, the rest give the height in tenths of a millimetre. So CR2032 is a lithium round cell, 20 mm across and 3.2 mm tall. Watch and hearing-aid cells also carry older trade names (AG, SR, PR) shown alongside below.
Chemistry, voltage and what it means
| Prefix | Chemistry | Nominal voltage | Typical use |
|---|---|---|---|
| CR | Lithium (Li-MnO2) | 3.0V | Motherboards, key fobs, medical, IoT |
| LR / AG | Alkaline | 1.5V | Toys, calculators, laser pointers |
| SR | Silver oxide | 1.55V | Watches, precision instruments |
| PR | Zinc air | 1.4V | Hearing aids |
Voltage matters more than size: a 3V CR cell and a 1.5V LR cell can share a diameter but must never substitute for each other. Silver-oxide SR cells hold a flatter, more stable voltage than alkaline, which is why watches and instruments prefer them.
Lithium (CR) coin cell sizes
| Code | Diameter | Height | Voltage |
|---|---|---|---|
| CR1220 | 12.5 mm | 2.0 mm | 3.0V |
| CR1620 | 16.0 mm | 2.0 mm | 3.0V |
| CR1632 | 16.0 mm | 3.2 mm | 3.0V |
| CR2016 | 20.0 mm | 1.6 mm | 3.0V |
| CR2025 | 20.0 mm | 2.5 mm | 3.0V |
| CR2032 | 20.0 mm | 3.2 mm | 3.0V |
| CR2430 | 24.5 mm | 3.0 mm | 3.0V |
| CR2450 | 24.5 mm | 5.0 mm | 3.0V |
The 20 mm CR20xx family is the most common source of mix-ups: CR2016, CR2025 and CR2032 share a diameter and differ only in height and capacity. Taller means more capacity — a CR2032 holds roughly twice the capacity of a CR2016.
Alkaline (LR / AG) and silver-oxide (SR) sizes
| Alkaline code | Equivalent | Diameter | Height |
|---|---|---|---|
| LR41 | AG3 / 392 | 7.9 mm | 3.6 mm |
| LR43 | AG12 / 386 | 11.6 mm | 4.2 mm |
| LR44 | AG13 / 357 | 11.6 mm | 5.4 mm |
| LR1130 | AG10 / 389 | 11.6 mm | 3.0 mm |
Silver-oxide SR cells often share these dimensions (for example SR44 matches LR44) but deliver a steadier 1.55V, so instruments that need stable voltage specify SR even where an LR would physically fit.
Frequently asked questions
Can I replace a CR2032 with a CR2025?
They share a 20 mm diameter, so a CR2025 usually fits the holder, but it is thinner (2.5 mm vs 3.2 mm) with less capacity and may sit loose. Use the exact code the device specifies for reliable contact and full runtime.
Is LR44 the same as AG13 and 357?
Yes — LR44, AG13 and 357 are common names for the same 11.6 × 5.4 mm 1.5V alkaline cell. The silver-oxide equivalent (SR44 / SR1154) shares the size but delivers a more stable 1.55V.
What does the number in a button cell code mean?
Under the IEC system the first two digits are the diameter in millimetres and the remaining digits are the height in tenths of a millimetre. CR2032 is therefore 20 mm in diameter and 3.2 mm tall.
Source button cells in bulk
JBWCELL manufactures the full range of button cells — lithium (CR), alkaline (LR/AG) and silver oxide (SR) — with OEM/ODM and private-label packaging. New to coin cells? See our coin cell buyer’s guide, or contact us for bulk pricing and datasheets.
