SR626SW
Watch Battery
Your complete guide to the 6.8×2.6mm silver-oxide battery that powers millions of watches worldwide. Learn specs, equivalents, and find the right replacement for your timepiece.
What Is the SR626SW Battery?
The SR626SW is a silver-oxide coin cell battery and one of the most widely used watch batteries in the world. It powers quartz watches, calculators, small electronic devices, and various precision instruments.
The battery measures 6.8mm in diameter and 2.6mm in height, with a nominal voltage of 1.55 volts. Silver-oxide chemistry provides stable voltage output throughout its life, making it ideal for timekeeping applications where accuracy matters.
25–28 mAh Capacity
Higher capacity than alkaline LR626 for longer runtime
1.55V Nominal Voltage
Constant voltage for accurate watch timing
5–10 Year Shelf Life
Long storage life when kept in cool, dry conditions
SR626SW Resources
Everything you need to choose, replace, and understand your watch battery
SR626SW vs Other Batteries
Understand how SR626SW differs from similar and commonly confused battery types
Find the Right
SR626SW Replacement
Compare brands, check equivalents, and ensure your timepiece keeps accurate time for years to come.
View EquivalentsWhy Silver-Oxide
Over Alkaline?
The SR626SW uses silver-oxide chemistry, which offers several advantages over alkaline batteries like the LR626. Silver-oxide provides more stable voltage throughout the battery's life, which is critical for quartz watches that rely on precise electrical signals for accurate timekeeping.
Alkaline batteries experience gradual voltage drop as they discharge, which can cause watches to run slow or stop before the battery is fully depleted. Silver-oxide maintains near-constant 1.55V until the end of its useful life, then drops quickly—giving you reliable performance and a clear indication when replacement is needed.
Additionally, silver-oxide batteries typically offer 25–28 mAh capacity compared to 15–17 mAh for alkaline equivalents, meaning your watch will run longer between replacements when you choose SR626SW.
Where SR626SW Is Used
The SR626SW powers a wide range of precision devices beyond wristwatches
Beyond quartz wristwatches and pocket watches, the SR626SW is found in calculators, digital thermometers, laser pointers, small LED flashlights, electronic toys, glucose meters, and various medical devices. Its stable voltage and compact size make it ideal for any application requiring reliable 1.55V power in a 6.8×2.6mm form factor.
Many fitness trackers, pedometers, and small wearable devices also use this battery size. When replacing batteries in these devices, always verify the correct size—some similar-looking batteries like SR621SW or SR616SW have the same diameter but different heights and are not interchangeable. Check our equivalent batteries guide for the full cross-reference.
SR626SW in Use
See how the SR626SW powers watches and small electronics worldwide
mm Dimensions
Nominal Voltage
mAh Capacity
Years Shelf Life
Common Questions
Everything you need to know about the SR626SW watch battery
The SR626SW powers quartz wristwatches, pocket watches, calculators, small LED lights, laser pointers, toys, and various precision instruments. It is one of the most common watch battery sizes worldwide.
LR626 is an alkaline equivalent with the same dimensions (6.8×2.6mm). It will fit and work, but silver-oxide SR626SW is preferred for watches because it provides more stable voltage and longer runtime. Alkaline voltage drops over time, which can affect timekeeping accuracy.
In a typical quartz watch, an SR626SW lasts approximately 1–3 years depending on the watch's power consumption, features (e.g., backlight, alarms), and usage. Simple analog watches often last 2–3 years.
The "SW" designation indicates the battery meets IEC 60086-3 standards for watch batteries. It ensures constant voltage suitable for precision timekeeping devices. Silver-oxide watch batteries without "SW" may not meet the same quality standards.
Yes. 377 and AG4 are common alternative labels for the same 6.8×2.6mm battery. AG4 can refer to either silver-oxide or alkaline—always check the package to ensure you get silver-oxide for best watch performance. Learn more on our equivalent batteries page.
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