SR721SW Battery Equivalent
SR721SW is the same cell as SG11, 361, 362 and SR58, so any of those codes will fit; LR721 is the same size in alkaline and will work, though it runs out sooner.
- Chemistry
- silver oxide
- Voltage
- 1.55 V
- Size (Ø × H)
- 7.9 × 2.1 mm
- Typical capacity
- 23–24 mAh
IEC designation SR721. Sold as 361 ( high drain, W) and 362 ( low drain, SW) .
SR721SW equivalents
Direct replacements
The same cell under another code. Any of these fits, whatever the brand.
- SG11
- 361 · High drain (W)
- 362 · Low drain (SW)
- SR58
- SR721
Upgrade or downgrade
Same size, different chemistry. Read the verdict before you buy.
| Cell | Chemistry | Voltage | Verdict |
|---|---|---|---|
| LR721 | 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 |
|---|---|---|
| SR41 | 7.9 × 3.6 mm | Same 7.9 mm diameter, but 3.6 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
| SR712SW | 7.9 × 1.2 mm | Same 7.9 mm diameter, but 1.2 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
| SR714SW | 7.9 × 1.4 mm | Same 7.9 mm diameter, but 1.4 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
| SR716SW | 7.9 × 1.65 mm | Same 7.9 mm diameter, but 1.65 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
| SR726SW | 7.9 × 2.6 mm | Same 7.9 mm diameter, but 2.6 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
| SR731SW | 7.9 × 3.1 mm | Same 7.9 mm diameter, but 3.1 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
| SR754SW | 7.9 × 5.4 mm | Same 7.9 mm diameter, but 5.4 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact. |
Low drain or high drain
SR721SW is sold under two numbers for the same case size. Manufacturers mark low-drain cells SW and high-drain cells W, which records what the cell is built to deliver rather than how big it is.
- Low drain (SW): 362
- A steady trickle of current: a quartz watch with hands, a thermometer, a key fob.
- High drain (W): 361
- Short bursts of heavier current: a watch with a backlight, an alarm or a chronograph.
Both are 1.55 V and both fit the same holder, so either will run the device. The matched one lasts longer.
About the SR721SW cell
On the shelf it is sold with a SR721 on the pack .
SR721SW questions
- Is SG11 the same as SR721SW?
- Yes. SG11 is another code for the same cell: silver oxide, 1.55 V, 7.9 × 2.1 mm.
- Is 361 the same as SR721SW?
- Yes. 361 is another code for the same cell: silver oxide, 1.55 V, 7.9 × 2.1 mm.
- Can I use LR721 instead of SR721SW?
- Works, but runs out sooner. Avoid in watches and medical devices.
- Will SR41 work in place of SR721SW?
- Same 7.9 mm diameter, but 3.6 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact.
- Will SR712SW work in place of SR721SW?
- Same 7.9 mm diameter, but 1.2 mm tall instead of 2.1 mm. Only if the holder fits; thinner cells can lose contact.
- What voltage is SR721SW?
- SR721SW is a 1.55 V silver oxide cell with a typical capacity of 23–24 mAh.
- What size is SR721SW?
- 7.9 mm across and 2.1 mm thick.