Button batteries are small, round power sources used in a wide range of compact electronic devices. Often referred to as coin batteries or coin cell batteries, these batteries come in various chemistries and sizes. Despite their common name, a button battery is technically a single electrochemical cell and should more accurately be called a button cell. However, the term “battery” is widely accepted and used interchangeably in everyday language.
Table of Contents
- What Is a Button Battery?
- Common Types of Button Batteries
- Button Battery Size and Type Comparison Chart
- Button Battery Applications in Electronics
- Battery Holders for Button Batteries
- Tips for Button Battery Use
- Did You Know About Button Batteries?
- Frequently Asked Questions About Button Batteries
- Conclusion
What Is a Button Battery?
A button battery is a compact, disc-shaped cell that provides a small but consistent voltage, typically 1.5V or 3V, depending on its chemistry. These batteries are designed for devices that require a small form factor and low power consumption. Examples include watches, car key fobs, calculators, hearing aids, and small electronic toys.
Although “battery” typically refers to multiple cells, button batteries are single-cell units. In professional and academic contexts, they are more accurately referred to as “cells.” Still, both terms are commonly used in the electronics and consumer industries.
Common Types of Button Batteries
Button batteries are available in various chemistries and sizes. Here’s a breakdown of the most common types:
Lithium Coin Batteries (3V)
- CR2032 – One of the most popular lithium coin cells. Common in car key fobs, fitness devices, and motherboards. Read our full guide on the CR2032 battery.
- CR2025 – Similar to CR2032 but thinner (2.5mm vs. 3.2mm)
- CR2016, CR2430, CR2450, CR2477, CR1220, CR1225, CR1616, CR1632, CR1620 – Used in watches, toys, medical devices, and other compact electronics
Alkaline and Silver Oxide Button Batteries (1.5V)
- LR44 – Widely used in small LED lights, laser pointers, and toys
- AG13 Button Cell Battery – An LR44 equivalent, often used in watches and laser tools
- Silver Oxide Cells – Used in precision devices such as analog watches and medical instruments
Button Battery Size and Type Comparison Chart
When choosing a button battery, it’s crucial to understand the differences between types like CR2032, LR44, CR2025, and many others. Each coin battery varies in size, voltage, and chemistry, which directly affects compatibility and performance in devices like car key fobs, watches, medical sensors, and toys.
The table below offers a detailed comparison of the most common button batteries to help you quickly identify the right replacement and understand possible equivalents.
| Model | Diameter (mm) | Height (mm) | Chemistry | Voltage | Typical Use Cases | Equivalent Models |
|---|---|---|---|---|---|---|
| CR2032 | 20.0 | 3.2 | Lithium | 3V | Key fobs, RTC, calculators | DL2032, BR2032 |
| CR2025 | 20.0 | 2.5 | Lithium | 3V | Watches, key fobs | DL2025, ECR2025 |
| CR2016 | 20.0 | 1.6 | Lithium | 3V | Toys, wristwatches | DL2016, ECR2016 |
| CR2450 | 24.5 | 5.0 | Lithium | 3V | Fitness trackers, medical | DL2450, BR2450 |
| CR2477 | 24.5 | 7.7 | Lithium | 3V | Sensors, beacons | DL2477 |
| CR1616 | 16.0 | 1.6 | Lithium | 3V | Remote controls | DL1616 |
| CR1632 | 16.0 | 3.2 | Lithium | 3V | Key fobs, watches | DL1632 |
| CR2430 | 24.5 | 3.0 | Lithium | 3V | IoT devices, alarms | DL2430 |
| CR1220 | 12.0 | 2.0 | Lithium | 3V | Calculators, toys | DL1220 |
| CR1225 | 12.0 | 2.5 | Lithium | 3V | Thermometers, gadgets | DL1225 |
| CR1620 | 16.0 | 2.0 | Lithium | 3V | Watches, medical devices | DL1620 |
| LR44 | 11.6 | 5.4 | Alkaline | 1.5V | Laser pointers, toys | AG13, A76, L1154 |
| AG13 | 11.6 | 5.4 | Alkaline | 1.5V | Same as LR44 | LR44, A76 |
Button Battery Applications in Electronics
Button batteries are essential in electronics, especially for powering:
- Real-time clocks (RTCs) on PC motherboards (e.g., CR2032)
- Memory backup systems in embedded devices
- Portable measurement tools
- Remote controls and wireless sensors
Due to their compact size and long shelf life, button batteries are ideal for embedded and hobby electronics projects. Many microcontroller-based projects, including those using Arduino, incorporate a button battery for RTC or low-power memory retention.
Battery Holders for Button Batteries
To use a button battery safely and securely in a project, a matching battery holder is essential. These holders:
- Prevent short circuits
- Ensure reliable contact with terminals
- Allow for easy battery replacement
Button battery holders are available for surface mount and through-hole configurations. For example, a common CR2032 holder can be found on RTC modules for Arduino.
Tips for Button Battery Use
- Choose the correct size and chemistry for your device. Substituting a CR2025 for a CR2032 may work in some cases, but not always reliably.
- Store button batteries in a cool, dry place to maintain their shelf life.
- Use a battery holder for prototyping and permanent installations.
- Watch for polarity when inserting the battery; incorrect insertion can damage circuits.
- Keep out of reach of children, as ingestion can be dangerous.
Did You Know About Button Batteries?
- The term “button battery” is a misnomer in technical terms. As they are single cells, “button cell” is more accurate.
- The CR prefix stands for Chromium-based lithium manganese dioxide chemistry, which delivers 3V.
- Button batteries have a long shelf life, often exceeding 5–10 years depending on chemistry.
- The CR2016 vs CR2032 comparison is mainly about thickness — CR2032 lasts longer due to a higher capacity.
- In CR2025 vs CR2032, both have the same diameter (20mm) but differ in thickness and capacity.
Frequently Asked Questions About Button Batteries
What is the difference between a button battery and a coin battery?
They are essentially the same. “Coin battery” often refers specifically to the larger lithium types like CR2032, while “button battery” is a more general term.
Is it correct to call a button battery a battery?
Technically, no. A single unit like a CR2032 is a cell, not a battery. But in common usage, “battery” is accepted.
What is the LR44 battery equivalent?
LR44 has several equivalents including AG13, A76, and 357. Check voltage and size when substituting.
What are button batteries used for?
They power small electronic devices like watches, hearing aids, key fobs, thermometers, and toys.
Are all button batteries 3V?
No. Lithium button batteries like CR2032 are 3V, while silver oxide and alkaline versions like LR44 are typically 1.5V.
Conclusion
Button batteries are compact, versatile power sources essential to modern electronics. While they’re technically cells, the term “button battery” is universally accepted. From CR2032 and CR2025 to LR44 and silver oxide cells, these components play a crucial role in both consumer and embedded electronics.