377 is the SR626SW: a 1.55 V silver oxide cell, 6.8 × 2.6 mm, with a typical capacity of 24–27 mAh.

Is 377 the same as SR626SW?

Yes. They are two codes for one cell, so a pack marked either way holds the same battery.

What can I use instead of 377?

Any code in the direct replacement list above. LR626 is the same size in another chemistry: Works, but runs out sooner. Avoid in watches and medical devices.

1.55 V, the same as any other SR626SW.

377 Battery Equivalent

377 is the SR626SW cell: 1.55 V silver oxide, 6.8 × 2.6 mm, so anything marked SG4, 376 and SR66 is the same battery and will fit.

Full SR626SW page: every equivalent, the sizes and what not to use

Chemistry: silver oxide
Voltage: 1.55 V
Size (Ø × H): 6.8 × 2.6 mm
Typical capacity: 24–27 mAh

IEC designation SR626. Sold as 376 ( high drain, W) and 377 ( low drain, SW) .

What the 377 code is

377 is one of the three-digit numbers Energizer and Renata use for silver-oxide watch cells. The digits encode nothing about the size, which is why a 377 and its IEC name look unrelated.

The IEC code for the same cell is SR626SW: silver oxide, 1.55 V, 6.8 × 2.6 mm.

377 is the low-drain number for SR626SW: built for a steady trickle, such as a plain quartz watch movement. The same case size is also sold as 376, the high-drain number. Both are 1.55 V and both fit the same holder.

SR626SW equivalents

Direct replacements

The same cell under another code. Any of these fits, whatever the brand.

SG4
376 · High drain (W)
377 · Low drain (SW)
SR66
SR626

Upgrade or downgrade

Same size, different chemistry. Read the verdict before you buy.

Cell	Chemistry	Voltage	Verdict
LR626	alkaline	1.5 V	Downgrade Works, but runs out sooner. Avoid in watches and medical devices.

Similar size, check the fit

Same diameter, different thickness. These are not drop-in replacements.

Cell	Size	Verdict
SR616SW	6.8 × 1.65 mm	Same 6.8 mm diameter, but 1.65 mm tall instead of 2.6 mm. Only if the holder fits; thinner cells can lose contact.
SR621SW	6.8 × 2.1 mm	Same 6.8 mm diameter, but 2.1 mm tall instead of 2.6 mm. Only if the holder fits; thinner cells can lose contact.

377 questions

What battery is 377?: 377 is the SR626SW: a 1.55 V silver oxide cell, 6.8 × 2.6 mm, with a typical capacity of 24–27 mAh.
Is 377 the same as SR626SW?: Yes. They are two codes for one cell, so a pack marked either way holds the same battery.
Is 377 low drain or high drain?: 377 is the low-drain number for SR626SW: built for a steady trickle, such as a plain quartz watch movement. The same case size is also sold as 376, the high-drain number. Both are 1.55 V and both fit the same holder.
What can I use instead of 377?: Any code in the direct replacement list above. LR626 is the same size in another chemistry: Works, but runs out sooner. Avoid in watches and medical devices.
What voltage is 377?: 1.55 V, the same as any other SR626SW.