Duracell 371/370 Silver Oxide Battery (SR920)

This is a single silver oxide button cell in the 371/370 size, rated at 1.5 volts, with the code SR920 printed on the card. Silver oxide is the chemistry chosen where a small cell has to hold a steady voltage across most of its working life rather than fade away gradually, which is why it is the usual choice for quartz watches and small precision instruments. The card also lists the equivalents V371, V370, SR69, SR920W, SR920WS, SR921W and SR921WS, so if the cell you are replacing carries any of those numbers, this is the same item under another name.

You will find cells of this size in wristwatches, small clocks, calculators, laser pointers and digital thermometers, and the surest way to identify the one you need is to read the number printed on the cell already in the device rather than measure it. Button cells in this family look almost identical to the eye, so matching the printed code matters far more than matching the look. If you are opening a watch back yourself, work over a cloth on a clear table, and handle the new cell by its edges so the flat faces stay clean.

You receive one cell, sealed on the blister card the manufacturer supplies. The pack carries a keep out of reach of children warning, and that is worth taking seriously with any button cell: a swallowed cell is a serious hazard, so keep spares on the card until you need them and take the spent one to a battery recycling point. The pack also states long lasting, power guaranteed. Minimum order is ten units, sold in multiples of ten, which suits a repair bench or a workshop drawer better than a single swap. We stock other Duracell specialist cells alongside it, including CR2032, LR44, SR621 and SR626.

My watch takes a 370, not a 371. Is this the right cell?

The pack is printed 371/370 and covers both references, so a device calling for either number takes this cell. Check the old cell before fitting.

How do I work out which button cell my device needs?

Read the code printed on the face of the cell already fitted, or check the manual. Cells in this family look alike, so the printed number is what you match.

Is this the same as an SR920W, SR921W or SR69?

Yes. The card lists V371, V370, SR69, SR920W, SR920WS, SR921W and SR921WS as equivalents for this cell, so any of those references will be met.

How many cells do I actually receive?

One cell on its own blister card. The minimum order on this listing is ten of those cards, sold in multiples of ten, so ten cells in total.

Does the manufacturer state a shelf life for this cell?

No figure is printed on the retail pack, so we state none.

What voltage does it give and does that drop as it runs down?

It is a 1.5 volt cell. Silver oxide chemistry is used in timekeeping because it holds close to its nominal voltage for most of its life.