Coin batteries, also known as button cells, are small, circular, and flat batteries commonly used in a variety of electronic devices.
Coin batteries are categorized by their chemical composition. Common types include:
- Lithium Manganese Dioxide (LiMnO2 or Li-M): Known for high energy density, stable 3-volt output, and long shelf life. Used in car key fobs, computer motherboards, and remote controls. Examples are CR2032, CR2025, and CR2016.
- Alkaline Manganese Dioxide: Affordable and readily available with a stable 1.5-volt output. Suitable for low-drain devices like remote controls and toys. Examples include LR44, LR41, and AG13.
- Silver Oxide: Offer a stable 1.55-volt output, high capacity, and long lifespan. Often found in watches and hearing aids. Examples are SR626SW, SR44, and SR41.
- Zinc-Air: Primarily used in hearing aids, providing high energy density and a voltage range of 1.4 to 1.45 volts. They are activated by air and have a shorter lifespan once opened. They are considered more environmentally friendly than lithium batteries.
- Zinc-Carbon: A cost-effective option with a 1.5-volt output for low-drain devices like clocks and calculators, but with a shorter shelf life. Examples include AG0, AG1, and AG3.
Coin cells are identified by codes indicating their chemistry and dimensions. The numbers specify the diameter and height.
- CR2032: 20mm diameter, 3.2mm height, 3V; used in calculators, motherboards, and remote controls.
- LR44 (AG13): 11.6mm diameter, 5.4mm height, 1.5V; used in toys and small electronics.
- SR626SW (377): 6.8mm diameter, 2.6mm height, 1.55V; commonly used in watches.
- ZA312 (Brown Tab): 7.9mm diameter, 3.6mm height, 1.4V; used in hearing aids.
Most coin batteries are non-rechargeable, offering a longer shelf life and wider availability. Rechargeable options exist but have a shorter shelf life due to self-discharge, though they offer lower long-term costs.
Consider these factors when selecting a coin cell:
- Device compatibility: Match the size, voltage, and chemistry to the device’s requirements.
- Performance requirements: Evaluate factors like operating temperature, energy density, and shelf life.
- Safety and certifications: Look for safety features and certifications such as IEC, UL, and CE.
- Brand and quality: Choose reputable brands for reliability.
- Environmental considerations: Dispose of used batteries properly, especially lithium-ion batteries.
Selecting the correct battery ensures proper function and longevity of your device.
How do I know which coin battery I need?
Measure the old battery’s diameter and height, or consult the device’s manual to find out the recommended battery size. Ensure that the replacement battery matches these dimensions. Voltage is another critical specification. Most button batteries have a voltage range between 1.2V and 3V.