About Button Cell Battery Specifications

Button cell batteries, also known as coin batteries, are small, round batteries commonly used in compact electronic devices such as watches, hearing aids, calculators, and medical devices. Their small size and lightweight design make them ideal for powering devices where space is limited. Understanding the specifications of button cells is essential for choosing the right battery for specific applications.

Key Specifications of Button Cells
1. Size and Dimensions

Button cell batteries come in various sizes, with diameters typically ranging from 5 mm to 25 mm and heights from 1 mm to 6 mm. The size of the battery is crucial for compatibility with the device. Below is a table illustrating the dimensions of some common button cell types:

2. Voltage
Button cell batteries typically provide a nominal voltage of either 1.5V or 3V, depending on their chemistry. Some common types of button cell chemistries include:

• Alkaline: 1.5V
• Silver Oxide: 1.55V
• Lithium: 3V
• Zinc-Air: 1.4V (commonly used in hearing aids)

The voltage of the battery is an essential factor to consider, as different devices require different voltages to operate correctly.

3. Capacity (mAh)

The capacity of a button cell battery is measured in milliampere-hours (mAh), which indicates how much energy the battery can deliver over time. Capacities vary based on battery size and chemistry. Below are the typical capacities for some popular button cells:

4. Chemistry
The type of chemical composition inside the battery affects its voltage, capacity, and application. The most common chemistries used in button cells include:

5. Operating Temperature
Button cell batteries typically have an operating temperature range between -20°C and 60°C, but this can vary depending on the chemistry. Lithium button cells, for example, have a broader operating temperature range compared to alkaline or zinc-air types, making them more suitable for devices exposed to extreme temperatures.

6. Shelf Life
Shelf life refers to how long a battery can be stored without significant loss of charge. Lithium button cells generally have a shelf life of 10 years or more, while alkaline and silver oxide batteries have shorter shelf lives of around 3 to 5 years. Zinc-air batteries have the shortest shelf life once activated, as they rely on air exposure to generate power.

7. Self-Discharge Rate
Self-discharge is the rate at which a battery loses its charge while not in use. Lithium button cells have the lowest self-discharge rate, typically around 1% per year, making them ideal for long-term use in devices like watches. Alkaline and silver oxide batteries have higher self-discharge rates, which can reduce their capacity over time if not used.

Common Button Cell Battery Types and Their Codes

Button cells are designated by codes that reflect their size and chemistry. Here are some common button cell battery types:

Button cell batteries are essential components in a wide variety of small electronic devices, and their specifications—such as size, voltage, capacity, and chemistry—play a key role in determining their suitability for different applications. Understanding these specifications ensures that you choose the right button cell battery to match the power needs of your devices, enhancing performance and longevity.