Button Battery Sizes Chart

Button batteries, also known as coin cells, are compact, round batteries widely used in small electronic devices such as watches, key fobs, and medical instruments. These batteries follow a standardized naming system that encodes their dimensions and chemical composition, ensuring compatibility across manufacturers, which you can see in the chart below:

Button Battery Sizes Chart

Decoding Button Battery Codes

The International Electrotechnical Commission (IEC) standardizes button battery codes, such as CR2032, based on their physical characteristics:

• First letter(s): Indicates the battery’s chemical composition:
  • C: Lithium manganese dioxide (3V)
  • S: Silver oxide (1.55V)
  • L: Alkaline (1.5V)
• First two digits: Represent the diameter in millimeters (e.g., 20mm for CR2032)
• Last two digits: Indicate the height in tenths of a millimeter (e.g., 3.2mm for CR2032)

For example, a CR2032 battery has a 20mm diameter and a 3.2mm height.

What Are the Sizes of Button Batteries?

Button batteries come in a variety of sizes, each with a unique code that indicates its size. The most common button battery sizes are:

• LR44: Popular for small electronic devices such as calculators and watches. Also known as AG13, A76, and 357.
• CR2032: Commonly used in small devices such as remote controls and key fobs.
• CR2025: Similar in size to the CR2032 but has a lower capacity.
• LR41: Used in small electronic devices such as thermometers and toys. Also known as AG3, 392, and SR41.

Other less common button battery sizes include LR43, LR626, CR1616, and CR2016.

How Do I Know What Size Button Battery I Have?

To determine the size of a button battery needed for your device, check the battery compartment or the device manual. The battery compartment may have the size printed on it, or a code that can be referenced in the manual. If you don’t have the manual, search online for the device’s specifications to determine the correct battery size.

What Is the Most Common Button Battery Size?

The LR44 is one of the most common button battery sizes, used in a wide variety of small electronic devices and readily available at most stores. The CR2032 is also a popular size, particularly for small devices that require a higher capacity battery.

What Size Is a 1.5V Button Cell?

A 1.5V button cell battery is commonly referred to as an LR44 battery. This battery is used in various small electronic devices and has a capacity of approximately 150mAh.

Common Button Battery Sizes and Applications

Button batteries come in various sizes, each serving specific applications. Below are some of the most common sizes and their uses:

Small-Diameter Cells (<10mm)

• SR521SW (5.8×2.1mm) – Used in microelectronics and jewelry trackers.
• LR754 (7.9×5.4mm) – Found in laser pointers and digital thermometers.

Mid-Size Cells (10–15mm)

• CR1220 (12.5×2.0mm) – Common in fitness trackers and IoT sensors.
• SR44 (11.6×5.4mm) – Used in diving computers and photogate timers.

Large-Diameter Cells (>15mm)

• CR2450 (24.5×5.0mm) – Used in industrial RFID tags and automotive TPMS.
• CR927 (9.5×2.7mm) – Found in slim devices like earbud cases.

Voltage Classifications and Chemistry Relationships

Button batteries fall into three primary voltage categories based on their chemistry:

1. 3V Lithium (CR Series): High energy density, used in automotive key fobs and CMOS memory backup.
2. 1.55V Silver Oxide (SR Series): Provides stable voltage output for precision instruments such as watches and medical devices.
3. 1.5V Alkaline/Zinc-Air (LR/ZR Series): Used in calculators, hearing aids, and toys.

Compatibility Challenges and Safety Considerations

Physical Interchangeability Risks

While button batteries adhere to standard dimensions, substituting one chemistry for another can be hazardous:

• Using a 3V CR2032 in place of a 1.5V LR44 can damage sensitive circuits.
• Inserting thicker batteries in compartments designed for thinner ones may compromise casing integrity.

In 2024, an Australian recall involved CR2450 cells incorrectly labeled as CR2032, causing failures in tablet motherboards.

Child Safety and Ingestion Prevention

Button batteries pose serious ingestion risks, particularly for young children. The Royal Children’s Hospital Melbourne reports 23 button battery ingestion cases monthly. Recent Australian regulations (2023) mandate:

• Child-resistant packaging for batteries ≥16mm diameter.
• Bitter coatings to deter swallowing.
• Battery compartments requiring tools for access.

Manufacturers have responded with innovations like Energizer’s 3-in-1 Child Shield battery, featuring a bitter coating and moisture-activated blue dye for ingestion alerts (Parents.com).

Technological Advancements and Future Trends

Rechargeable Lithium Polymer Alternatives

To address environmental concerns, manufacturers are developing rechargeable LiPo button cells, such as:

• LIR2032: A 500-cycle rechargeable variant with 70mAh capacity.
• Solid-state designs: Eliminating liquid electrolytes for improved safety.

Miniaturization vs. Performance Tradeoffs

Ongoing research aims to improve button battery performance through:

• 3D-structured anodes, boosting energy density by 300% in sub-10mm cells.
• Wireless charging integration, enabling sealed medical implants.

Conclusion

The button battery industry maintains rigorous standardization while evolving to meet modern demands. Engineers must balance IEC dimensional compliance with chemistry-specific performance characteristics, particularly as IoT and medical devices drive demand for smaller, high-capacity cells.

Future advancements in solid-state electrolytes and rechargeable architectures promise sustainability without compromising the compact form factor that makes button batteries indispensable in modern technology.