Need to replace your watch battery? The SR626SW is the world's most common button cell, but finding the right equivalent can be confusing. This guide cuts through the jargon and gets you the correct battery—fast.

Before diving into equivalents, let's clarify what SR626SW means and why it’s the standard for so many devices.

The SR626SW is a 1.55V battery shaped like a small button, measuring about 7mm wide and 3mm thick. It is used in watches, calculators, small medical devices, and key fobs. "SR" means it's made with silver oxide, "626" refers to its size, and "SW" means it's designed for devices that use a small, steady amount of power.

SR626SW Battery Equivalent Chart

*AG4 batteries can be either silver oxide or alkaline—check the label closely, as only silver oxide batteries (usually marked as SR626SW or 377) are chemically compatible with precision devices. Alkaline batteries (marked LR626 or AG4 alkaline) may not perform correctly and can damage your device.

Using an LR626 alkaline battery instead of a silver oxide battery can cause voltage drops that disrupt a quartz watch's accuracy, making it run fast. Alkaline batteries are also more likely to leak, which can harm circuits. The minimal upfront savings are outweighed by the cost of device repairs.
Always choose silver oxide for watches and precision devices.

Tips：Selecting a reputable brand ensures reliability. Avoid unbranded AG4 cells from unknown sources—they are prone to counterfeits and poor performance.

Tools Needed

• Plastic tweezers (never metal)
• Case knife or small flat screwdriver
• Soft cloth

Step 1: Open the Case
Locate the notch on the caseback. Insert the case knife at a <15° angle and twist gently to pop open the case. For screw-down cases, use the correct blade size to prevent slot damage.

Step 2: Remove and Replace
Note battery orientation (+ side usually up). Lift the old battery with plastic tweezers. Insert a new SR626SW/377 with the same orientation. Ensure full contact with metal clips.

Step 3: Verify and Close
Check that the second hand moves (analog) or the display activates (digital). Align the caseback properly and press until sealed—no gaps.
Safety Notes
Work on a soft surface to prevent crystal scratching.
Don't touch the battery terminals with your fingers—oils can cause corrosion.
Dispose of old batteries immediately at the recycling point.

Q: SR626SW vs 377—what's the difference? 

A: None. SR626SW is the technical name; 377 is what most stores call it. They are the same battery, just labeled differently.

Q: Can I use LR626 instead of SR626SW? 

A: No. LR626 is a different type (alkaline, 1.50V), and it will not work well. Only use 1.55V silver oxide batteries for your devices.

Q: How often should I replace my watch battery? 

A: Typically 2–3 years for analog watches, 1–2 years for digital watches with alarms or backlights. Replace immediately if the watch runs slowly or stops.

Q: My watch is losing time—is it the battery? 

A: Probably yes. Silver oxide batteries keep working at full strength almost until they run out. If your watch is running slow, the battery is almost empty—change it soon.

Q: Why did my new battery die in 3 months? 

A: Probable causes: (1) counterfeit battery with reduced capacity, (2) expired stock (check date code), (3) high-drain device requiring SR626SW "W" (high-drain) variant, or (4) device malfunction causing parasitic drain.

Where to Buy Genuine SR626SW Batteries
For reliable performance and device protection, source from authorized distributors with verified supply chains. Counterfeit batteries flood discount marketplaces—authenticity matters when protecting precision electronics.

Welllinkchip supplies certified SR626SW and 377 batteries from top brands: Energizer, Maxell, Sony, and Renata. We offer fresh stock, competitive pricing, and OEM support for bulk orders.