SR626SW 377 Watch Battery: Energizer 377BPZ-2
The Energizer 377BPZ-2 is a two-pack of 377 silver oxide button cells, the size also sold as SR626SW. Each cell is 6.8 mm wide and 2.6 mm thick, gives 1.55 volts and is made for small watches and compact electronics.
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Is This the Right Battery for Your Watch?
Energizer lists its 377 as a replacement for SR626SW, SR66, D377, SB-AW, 377BP and 376/377. Run this quick check against your watch before you order.
LR626 and AG4 cells share the size but are alkaline at 1.5V, and are not the same as a silver oxide 377. Maxell sells the 376 (SR626W) as the high-drain version for watches with a light or alarm. Follow the number your watch maker specifies.
Energizer 377 Specifications
| Property | Detail |
|---|---|
| Brand / model | Energizer 377 (retail pack 377BPZ-2, two cells) |
| Replacement references | 376/377, 377BP, D377, SB-AW, SR626SW, SR66 (Energizer list) |
| Chemistry | Zinc / silver oxide (Zn/Ag₂O), non-rechargeable |
| Nominal voltage | 1.55 V (product pages often round to 1.5 V) |
| Dimensions (standard SR626SW / 377) | 6.8 mm diameter × 2.6 mm high |
| Typical weight | 0.42 g per cell |
| Typical capacity | 24 mAh (47 kΩ continuous load, 21°C, 1.2 V cut-off, per Energizer datasheet) |
| ANSI/NEDA designation | 1176SO |
| IEC designation | SR66 |
| Storage life claim | Up to 5 years in storage (not in-watch runtime) |
| Mercury | Marketed as zero mercury |
| Pack contents | 2 individual cells in a blister pack (UPC 039800109637) |
Capacity is a typical figure and changes with load, temperature and cut-off voltage. Some retail pages list 27 mAh; this page uses the figure from Energizer’s datasheet.
377 Watch Battery Replacement Difficulty
The battery itself is easy to buy and handle. Difficulty comes from the watch: a case with a battery hatch is simple, while a sealed or water-resistant case is a job for a watch repairer. Tap a slice to highlight it.
- 15% Choosing the right battery
- 35% Opening the case
- 25% Retainer & polarity
- 25% Closing & sealing
- Case back type: a hatch is easy, a snap-back or threaded back needs the matching opener.
- Battery retainer: some watches use a screwed strap or a spring-loaded arm over the cell.
- Reset: some movements need a reset after a battery change.
- Water resistance: the seal needs checking, and a pressure test needs workshop equipment.
The score and the effort split are an editorial estimate for a typical quartz watch, not an official rating.
How to Replace a 377 Watch Battery
This is a general overview. Steps differ by watch. Follow your watch manual where it gives instructions. Tap each step to tick it off as you go.
- 1Confirm the battery and case typeCheck the manual or old cell for 377 or SR626SW, and see how the case back opens before you touch it.
- 2Open the caseUse the tool that matches the case back, such as a case knife, a case wrench or a screwdriver. Stop if the tool slips.
- 3Swap the cellNote how the old cell sits and which side faces up. Release the retainer, lift the cell out and fit the new 377 with plastic tweezers.
- 4Reset, check and closeFollow any reset step for your movement, check the gasket and press or screw the case back closed. Set the time and date.
Check that the cell is the right type, sits flat under its retainer and faces the right way. Some movements need a reset. Check your watch instructions.
Closing the case does not confirm water resistance. If your watch is rated for water, have the seal checked by a watch shop.
Other Devices That Use a 377 (SR626SW)
Energizer lists watches, toys, glucose monitors and calculators for its 377. Miyota names SR626SW for several of its movements. Confirm the battery type in your device manual first.
- Quartz watchesCheck the number in your manual
- Miyota 2015, 2025 & 2035Movements specified for SR626SW
- CalculatorsListed by Energizer
- Toys & gamesListed by Energizer
- Glucose monitorsCheck your manual
- Heart-rate monitorsCheck your manual
- Keyless entry remotesCheck your manual
Safety, Storage & Disposal
Button batteries can cause serious injury or death if swallowed. Do not wait for symptoms. In the US, call the National Battery Ingestion Hotline on 800-498-8666 or Poison Help on 800-222-1222 straight away, and go to an emergency department.
- Never recharge, open or burn it, and do not fit it backwards.
- Do not mix battery types, and replace all cells in a device at the same time.
- Store in a cool, well-ventilated place. Heat can shorten battery life.
- Follow local rules for disposal and use a collection point that accepts button cells.
SR626SW 377 Watch Battery: FAQ
Is SR626SW the same as 377?
SR626SW and 377 are two names for the same silver oxide watch battery size. Energizer lists SR626SW as a replacement reference for its 377. Capacity can still differ from brand to brand.
How many batteries come in the Energizer 377BPZ-2 pack?
Two separate 377 cells in a blister pack. They are not joined together.
Is the 377 a 1.5V or 1.55V battery?
The Energizer datasheet gives a nominal voltage of 1.55V. Product pages often round this to 1.5V.
How long does a 377 last in a watch?
It depends on the watch. Energizer’s five-year figure refers to storage, not running time. Movement makers such as Miyota publish their own battery-life figures for specific movements, for example three years for the 2035. These are not a guarantee for every watch.
Is the Energizer 377 rechargeable?
No. It is a single-use silver oxide cell. Energizer warns that recharging can cause leakage or rupture, and that a cell fitted backwards can be charged by accident.
Can I use an LR626 or AG4 instead?
LR626 and AG4 share the 6.8 × 2.6 mm size, but they are alkaline cells rated at 1.5V. A watch made for SR626SW should use a silver oxide 377 or SR626SW cell.
What separates 377 (SR626SW) from 376 (SR626W)?
Maxell sells the SR626SW as a low-drain cell for watches without a backlight or alarm, and the SR626W as a high-drain cell. Energizer covers both numbers with its 377/376 datasheet and lists 376/377 as replacements for its 377.
Which way round does the battery go?
Follow the polarity marks in your watch and the way the old cell sat. The correct side is set by the watch, not by the battery number.
Why has my watch not restarted after a battery change?
Check that the cell is the correct type, sits flat under its retainer and faces the right way. Some movements also need a reset after a battery change; the instructions for your watch will say.
Will a battery change affect water resistance?
It can. Opening the case disturbs the seal, and gaskets age. Seiko notes that water resistance is not permanent and advises regular checks, and its battery service can include new gaskets and a pressure test.
How should I dispose of a used 377?
Follow your local battery disposal rules and use a collection point that accepts button cells. Keep used cells away from children until you drop them off.
