Everything You Need to Know About the SR920SW Battery

The SR920SW battery is a small, silver oxide button cell battery commonly used in a variety of electronic devices. Known for its reliability, long shelf life, and stable voltage output, the SR920SW is a popular choice for powering small gadgets such as watches, calculators, medical devices, and other compact electronics. In this article, we’ll explore everything you need to know about the SR920SW battery, including its specifications, applications, advantages, disadvantages, and tips for proper usage and disposal.

1. Overview of the SR920SW Battery

The SR920SW is a silver oxide button cell battery, which means it uses silver oxide as the cathode and zinc as the anode. Silver oxide batteries are known for their high energy density and stable voltage output, making them ideal for devices that require consistent power over a long period.

Key Specifications:

• Chemistry: Silver Oxide (Ag2O)
• Voltage: 1.55V
• Capacity: Approximately 40-50 mAh (milliampere-hours)
• Diameter: 9.5 mm
• Height: 2.1 mm
• Weight: Around 0.6 grams
• Terminal Type: Flat contacts
• Operating Temperature Range: Typically between 0°C and 60°C (32°F to 140°F)

The SR920SW is often compared to other similar-sized batteries, such as the LR921 (alkaline) and 371 (silver oxide). While these batteries may have similar dimensions, their chemical composition and performance characteristics differ.

2. Applications of the SR920SW Battery

The SR920SW battery is widely used in small electronic devices that require a compact and reliable power source. Some common applications include:

A. Watches

The SR920SW is frequently used in analog and digital watches, particularly those with additional features like backlighting, alarms, or chronographs. Its stable voltage ensures accurate timekeeping over an extended period.

B. Calculators

Many handheld calculators, especially scientific or graphing models, rely on the SR920SW for power. Its ability to maintain a consistent voltage is crucial for the accurate functioning of these devices.

C. Medical Devices

The SR920SW is used in small medical devices such as glucose meters, thermometers, and hearing aids. Its reliability and long life make it a trusted choice for health-related applications.

D. Key Fobs and Remote Controls

Some car key fobs and remote controls use the SR920SW battery due to its compact size and ability to deliver consistent power.

E. Toys and Gadgets

Small electronic toys, LED lights, and other gadgets often use the SR920SW battery to provide a lightweight and efficient power source.

3. Advantages of the SR920SW Battery

The SR920SW battery offers several advantages that make it a preferred choice for many applications:

A. Stable Voltage Output

Silver oxide batteries like the SR920SW provide a stable voltage of 1.55V throughout their lifespan. This ensures consistent performance in devices that require precise power levels.

B. Long Shelf Life

The SR920SW has a shelf life of up to 5 years when stored properly. This makes it an excellent choice for backup power or infrequently used devices.

C. High Energy Density

Silver oxide batteries have a higher energy density compared to alkaline batteries of the same size. This means they can store more energy and last longer in high-drain devices.

D. Leak Resistance

The SR920SW is less prone to leakage compared to alkaline batteries, reducing the risk of damage to the devices it powers.

E. Compact Size

Its small size makes it ideal for use in compact electronic devices where space is limited.

4. Disadvantages of the SR920SW Battery

While the SR920SW has many advantages, there are a few drawbacks to consider:

A. Higher Cost

Silver oxide batteries are generally more expensive than alkaline batteries. However, their longer lifespan and superior performance often justify the higher price.

B. Environmental Concerns

Silver oxide batteries contain small amounts of silver, which can be harmful to the environment if not disposed of properly. Recycling is recommended to minimize environmental impact.

C. Limited Availability

The SR920SW may not be as widely available as alkaline batteries, especially in smaller retail stores. However, it can usually be found online or in specialty electronics stores.

5. Comparing SR920SW with Other Batteries

The SR920SW is often compared to other button cell batteries, such as the LR921 (alkaline) and 371 (silver oxide). Here’s how they stack up:

A. SR920SW vs. LR921

• Chemistry: SR920SW uses silver oxide, while LR921 uses alkaline.
• Voltage: Both provide 1.5V, but the SR920SW maintains a more stable voltage over time.
• Capacity: The SR920SW typically has a higher capacity (40-50 mAh) compared to the LR921 (30-40 mAh).
• Cost: The SR920SW is more expensive but offers better performance and longevity.

B. SR920SW vs. 371

• Size: The 371 battery is slightly larger in diameter (9.5 mm vs. 9.2 mm) and height (2.6 mm vs. 2.1 mm).
• Capacity: The 371 has a slightly higher capacity (50-55 mAh) compared to the SR920SW.
• Applications: The 371 is often used in similar devices but may be preferred for higher-drain applications.

6. Tips for Using and Maintaining SR920SW Batteries

To get the most out of your SR920SW battery, follow these tips:

A. Proper Installation

Ensure the battery is installed correctly, with the positive (+) and negative (-) terminals aligned as indicated in the device. Improper installation can lead to poor performance or damage.

B. Storage

Store the SR920SW in a cool, dry place away from direct sunlight and extreme temperatures. This helps preserve its shelf life and performance.

C. Avoid Mixing Batteries

Do not mix old and new batteries or batteries of different chemistries in the same device. This can lead to uneven performance and potential damage.

D. Regular Replacement

Replace the battery as soon as you notice a decline in device performance. Delaying replacement can cause the device to malfunction or the battery to leak.

7. Disposal and Recycling of SR920SW Batteries

Proper disposal of the SR920SW battery is essential to minimize environmental impact. Here’s what you need to know:

A. Recycling

Silver oxide batteries contain valuable materials like silver that can be recycled. Many electronics stores and recycling centers accept used button cell batteries for recycling.

B. Local Regulations

Check your local regulations for specific guidelines on battery disposal. Some areas have designated drop-off points or special collection programs for small batteries.

C. Safe Handling

Avoid puncturing or damaging the battery, as this can release harmful chemicals. Store used batteries in a secure container until they can be properly recycled.

8. Frequently Asked Questions (FAQs)

Q1: Can I replace an SR920SW with an LR921 battery?

While the LR921 is a similar size, it has a lower capacity and less stable voltage. It’s best to use the battery type recommended by the device manufacturer.

Q2: How long does an SR920SW battery last?

The lifespan depends on the device and usage. In low-drain devices like watches, it can last 1-2 years or more.

Q3: Are SR920SW batteries rechargeable?

No, the SR920SW is a non-rechargeable battery. Attempting to recharge it can cause leakage or rupture.

Q4: Where can I buy SR920SW batteries?

They are available online, at electronics stores, and in some supermarkets. Look for reputable brands to ensure quality.

9. Conclusion

The SR920SW battery is a reliable and efficient power source for a wide range of small electronic devices. Its stable voltage, long shelf life, and compact size make it a popular choice for applications ranging from watches to medical devices. While it may be more expensive than alkaline alternatives, its superior performance and durability often justify the cost. By following proper usage, storage, and disposal practices, you can maximize the lifespan of your SR920SW battery and minimize its environmental impact. Whether you’re replacing a battery in a favorite gadget or powering a critical device, the SR920SW is a dependable option worth considering.