SR626SW Battery Equivalent: 377 Watch Battery Replacement Guide

The SR626SW battery is a small silver oxide button cell commonly used in analog watches, compact electronic devices, calculators, small instruments, and other low-drain circuits. It is often searched under several related terms, including SR626SW battery, SR626SW watch battery, 377 battery, watch battery SR626SW, and SR626SW replacement battery.

The most common replacement for an SR626SW battery is usually the 377 watch battery. However, battery replacement should not be based only on physical size. Voltage, chemistry, discharge behavior, and device current requirements also matter, especially for watches that need stable voltage over long operating periods.

This guide explains SR626SW battery specifications, equivalent models, 377 compatibility, silver oxide versus alkaline alternatives, and practical replacement checks for watches and small electronics.

SR626SW Battery Specifications

SR626SW is a silver oxide button cell with a nominal voltage of 1.55V. The code itself gives useful information about the battery type and size. "SR" usually refers to silver oxide chemistry, while "626" indicates a button cell size close to 6.8mm diameter and 2.6mm height.

Because SR626SW is a small coin or button battery, it is easy to confuse it with physically similar cells. The correct replacement should match the original size and provide suitable voltage stability for the device.

SR626SW Battery Equivalent and Cross Reference

The SR626SW battery has several common equivalent and cross-reference codes. These codes may vary by battery manufacturer, region, and product label, but they usually refer to the same or very similar silver oxide watch battery format.

When checking an SR626SW battery equivalent, it is important to compare more than one code. Different brands may use different markings for the same or similar silver oxide button cell, such as SR626SW, 377, SR66, SG4, and other regional references.

The Coin & Button Cell Battery Cross-Reference Guide provides a practical way to compare common coin and button cell battery codes before selecting a replacement. This is especially useful when the original battery uses a brand-specific code rather than the more common 377 or SR626SW marking.

Is SR626SW the Same as a 377 Battery?

In most watch battery replacement situations, SR626SW and 377 are treated as equivalent. A 377 battery is commonly used as the direct replacement for SR626SW in analog watches and other low-drain devices.

The important point is that 377 is typically a silver oxide watch battery, not an alkaline substitute. Silver oxide chemistry provides a more stable discharge voltage than alkaline chemistry, which makes it better suited for watches that require consistent operation over a long period.

For a watch battery SR626SW replacement, a silver oxide 377 is generally preferred over AG4 or LR626. Alkaline alternatives may fit physically, but they often have lower voltage stability and may not last as long in precision timekeeping applications.

SR626SW Watch Battery Applications

The SR626SW watch battery is most commonly used in analog watches. It may also appear in compact low-power electronic devices where a stable small button cell is required.

Common applications include:

• analog wristwatches
• small digital instruments
• compact calculators
• miniature clocks
• low-power electronic modules
• small measuring devices

In watches, stable voltage is more important than high pulse current capability. This is why silver oxide cells such as SR626SW and 377 are commonly used instead of alkaline equivalents.

SR626SW Replacement Battery Selection

When selecting an SR626SW replacement battery, the first check is physical size. The battery must fit the holder properly without excessive force. The second check is chemistry. For most watches, silver oxide chemistry is the better choice.

A proper SR626SW replacement should match these points:

• same approximate diameter: 6.8mm
• same approximate height: 2.6mm
• 1.55V silver oxide chemistry where possible
• compatible low-drain watch battery specification
• reliable brand or verified cross-reference code

Some battery compartments list only one number, such as 377, while others may show SR626SW or SR626. These are usually pointing to the same replacement family. If the device manual lists a specific chemistry or brand code, that information should take priority.

Silver Oxide vs Alkaline Alternatives

SR626SW is a silver oxide battery. Some physically similar batteries use alkaline chemistry, such as AG4 or LR626. These may fit into the same battery compartment, but they are not always the best replacement for a watch.

For a watch battery SR626SW equivalent, silver oxide is normally the safer choice. Alkaline alternatives may be acceptable in some toys or simple devices, but they may not provide the same long-term accuracy or service life in watches.

SR626SW vs SR626W

Some battery codes are very close but not identical. SR626SW and SR626W are physically similar silver oxide batteries, but the suffix can indicate different discharge characteristics.

In general, "SW" is associated with low-drain applications such as analog watches, while "W" is often associated with higher-drain applications. Many modern replacement guides may group these cells together, but it is still better to follow the device manufacturer's original recommendation.

For most standard analog watches, SR626SW or 377 is the expected replacement. If the original battery was marked SR626W, the device may require a battery with different discharge capability.

Common Brand References for SR626SW and 377

Different battery brands may print different codes on packaging even when the battery is compatible with SR626SW. This is one reason cross-reference checking is useful before replacement.

Brand markings can vary by region and packaging. The safest approach is to verify the battery code, chemistry, size, and intended application rather than relying only on one printed label.

Common Mistakes When Replacing SR626SW Batteries

Most SR626SW replacement problems come from choosing a physically similar battery without checking chemistry or code compatibility.

Common mistakes include:

• using an alkaline AG4 or LR626 when a silver oxide 377 is preferred
• forcing a battery into a tight holder
• installing the battery with reversed polarity
• touching the battery surface with dirty or oily fingers
• mixing old and new batteries in devices that use multiple cells
• assuming every 6.8mm button battery has the same performance

Button cells are small, but they still require careful handling. Poor contact, wrong polarity, or surface contamination can cause a watch to stop even when the battery itself is new.

SR626SW Battery Quick Reference Table

SR626SW is best understood as a small silver oxide watch battery family, with 377 being the most common replacement code. For watches and precision low-drain electronics, a silver oxide equivalent is normally the better choice than an alkaline substitute. Checking cross-reference codes, chemistry, voltage, and size before replacement helps avoid poor service life, unstable operation, or incorrect battery selection.