AG4, LR626, LR66, 177/376/377, SR626, SR626SW Battery Comphrehensive Knowledge

AG4, LR626, LR66, 177, 376, 377, SR626, and SR626SW are button cell batteries widely used in small electronics, with key differences in chemistry—alkaline versus silver oxide—affecting voltage stability, capacity, and suitable applications. Understanding their equivalents, voltage specs, capacity, and compatibility ensures optimal device performance and longevity, especially for precision instruments like watches and medical devices.

What Are the Physical Dimensions and Chemistry of AG4, LR626, and LR66 Batteries?

AG4, LR626, and LR66 button cells share identical physical dimensions of approximately 6.8 mm diameter and 2.6 mm thickness. They are alkaline batteries with a nominal voltage of 1.5 volts and a typical capacity of about 18 mAh. These batteries are generally non-rechargeable and used in consumer electronics where high voltage stability is less critical.

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Which Batteries Are Equivalent to 177, 376, 377, SR626, and SR626SW?

The 177, 376, and 377 are silver oxide button cells equivalent to the SR626 and SR626SW batteries. They also have dimensions of 6.8 mm diameter by 2.6 mm thickness but use silver oxide chemistry, offering a nominal voltage of 1.55 volts and a higher capacity ranging from 25 to 32 mAh. Silver oxide batteries maintain constant voltage throughout their life, making them ideal for precision devices like wristwatches and medical instruments.

How Do Voltage and Capacity Differ Between Alkaline and Silver Oxide Batteries?

Alkaline AG4/LR626 batteries have a nominal voltage of 1.5 volts but exhibit voltage decline over their lifespan, dropping to around 1.0 volt or lower near the end of life. Silver oxide SR626/SR626SW batteries have a slightly higher nominal voltage of 1.55 volts, maintaining a more stable voltage output until depletion, which contributes to longer device runtime and stable performance.

Typical Voltage and Capacity Comparison Chart

What Devices Commonly Use These Batteries?

Alkaline AG4 and LR626 batteries are often used in low-drain devices like calculators, toys, and remote controls. Silver oxide equivalents are preferred in precision devices like wristwatches, hearing aids, medical alarms, and LED flashlights, where voltage stability and reliable long-term power are essential.

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How Do Manufacturers and Standards Label These Batteries?

Battery labeling follows different standards:

• IEC standard: LR626 for alkaline; SR626 or SR626SW for silver oxide versions.
• ANSI standard: 177 for silver oxide batteries (equivalent to SR626SW).
• Manufacturers sometimes add suffixes like “SW” indicating compliance with the watch battery standard IEC 60086-3 and the use of sodium hydroxide electrolyte in silver oxide batteries.
• Markings such as AG, LR, or SR reveal chemistry type: AG and LR signify alkaline; SR and SG indicate silver oxide (SG also sometimes used variably).

What Are the Benefits of Choosing Silver Oxide SR626SW Over Alkaline AG4?

The SR626SW maintains a consistent 1.55 volts throughout its life, provides 30%-50% higher capacity compared to alkaline AG4 when considering typical device cutoff voltages, and exhibits slower voltage drop-off, enhancing device accuracy. Although generally more expensive, silver oxide batteries provide better performance for watches and sensitive electronics.

How Do the Different Battery Codes (177, 376, 377) Relate to Each Other?

Battery codes 177, 376, and 377 essentially refer to the same size but differ slightly in discharge rating or manufacturer guidelines:

• 376 is often a lower drain silver oxide version.
• 377 is a high-drain silver oxide battery.
• 177 is commonly used as a designation for silver oxide watch batteries.
  These variations cater to devices differing in power consumption, from simple analog watches to higher-drain digital models.

Are Alkaline AG4 and Silver Oxide SR626 Batteries Interchangeable?

Physically, yes—the batteries share the same size of 6.8 x 2.6 mm. However, their chemistry differences mean alkaline AG4 batteries may cause performance issues or shorter runtime in devices designed for silver oxide SR626 batteries. Using the chemically correct battery ensures device longevity and proper functioning.

What Precautions Should Be Taken When Replacing These Batteries?

Always verify device battery specifications and choose the recommended chemistry type. Avoid mixing chemistries and do not use silver oxide batteries in devices specifying alkaline if not recommended, or vice versa. Pay attention to voltage, capacity, and battery label markings. Proper disposal of old batteries according to local regulations is essential.

How Does Redway Power Contribute to Button Cell Battery Quality?

Redway Power, with over 13 years of experience as an OEM lithium battery pack factory, maintains stringent quality standards (ISO 9001:2015) and employs advanced MES manufacturing systems. They supply specialized batteries for applications requiring high reliability and safety, promoting innovations in battery chemistry and consistent product performance in small electronic devices.

Redway Power Expert Views

“Selecting the right button cell battery—whether alkaline AG4 or silver oxide SR626—is critical for device reliability and longevity. At Redway Power, we focus on manufacturing advanced lithium and silver oxide batteries with consistent voltage delivery and lifespan, supporting precision electronics with the energy they require. Our quality control and OEM expertise ensure customers receive batteries that meet rigorous standards for performance and safety.”

— Senior Battery Engineer, Redway Power

Conclusion

Understanding the comprehensive characteristics of AG4, LR626, LR66, 177, 376, 377, SR626, and SR626SW batteries involves considering size, chemistry, voltage, capacity, and intended application. Alkaline versions like AG4 offer affordable, general-purpose power with declining voltage, while silver oxide batteries such as SR626SW provide stable, longer-lasting voltage favored in precision devices. Choosing the ideal chemistry and brand—such as OEMs like Redway Power—ensures optimal device function and user satisfaction.

FAQs

Q: What is the voltage difference between AG4 and SR626SW batteries?
A: AG4 (alkaline) is 1.5 volts nominal, while SR626SW (silver oxide) is 1.55 volts nominal with more stable voltage output.

Q: Are LR626 and AG4 batteries the same?
A: Yes, they share identical size and alkaline chemistry and are interchangeable.

Q: Can I use SR626SW in place of AG4 batteries?
A: Technically yes, but SR626SW is preferred for watches and precision devices due to better voltage stability.

Q: What devices typically use these button cell batteries?
A: Watches, calculators, digital thermometers, remote controls, fitness devices, and hearing aids.

Q: How do Silver Oxide batteries maintain voltage better than alkaline?
A: Silver oxide chemistry sustains a flat discharge curve, providing consistent voltage output until the battery is nearly depleted.