SR42 Battery Equivalent
SR42 is the same cell as 242, 344, 350, 387S and SR1136, so any of those codes will fit; no other cell here is 11.6 × 3.6 mm at 1.5 V.
- Chemistry
- silver oxide
- Voltage
- 1.55 V
- Size (Ø × H)
- 11.6 × 3.6 mm
- Typical capacity
- 105 mAh
IEC designation SR1136. Sold as 344 ( low drain, SW) and 350 ( high drain, W) .
SR42 equivalents
Direct replacements
The same cell under another code. Any of these fits, whatever the brand.
- 242
- 344 · Low drain (SW)
- 350 · High drain (W)
- 387S
Similar size, check the fit
Same diameter, different thickness. These are not drop-in replacements.
| Cell | Size | Verdict |
|---|---|---|
| SR1116SW | 11.6 × 1.65 mm | Same 11.6 mm diameter, but 1.65 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact. |
| SR1120SW | 11.6 × 2.1 mm | Same 11.6 mm diameter, but 2.1 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact. |
| SR1126 | 11.6 × 2.6 mm | Same 11.6 mm diameter, but 2.6 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact. |
| SR1130SW | 11.6 × 3.1 mm | Same 11.6 mm diameter, but 3.1 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact. |
| SR43 | 11.6 × 4.2 mm | Same 11.6 mm diameter, but 4.2 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact. |
| SR44 | 11.6 × 5.4 mm | Same 11.6 mm diameter, but 5.4 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact. |
Low drain or high drain
SR42 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): 344
- A steady trickle of current: a quartz watch with hands, a thermometer, a key fob.
- High drain (W): 350
- 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.
SR42 questions
- Is 242 the same as SR42?
- Yes. 242 is another code for the same cell: silver oxide, 1.55 V, 11.6 × 3.6 mm.
- Is 344 the same as SR42?
- Yes. 344 is another code for the same cell: silver oxide, 1.55 V, 11.6 × 3.6 mm.
- Will SR1116SW work in place of SR42?
- Same 11.6 mm diameter, but 1.65 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact.
- Will SR1120SW work in place of SR42?
- Same 11.6 mm diameter, but 2.1 mm tall instead of 3.6 mm. Only if the holder fits; thinner cells can lose contact.
- What voltage is SR42?
- SR42 is a 1.55 V silver oxide cell with a typical capacity of 105 mAh.
- What size is SR42?
- 11.6 mm across and 3.6 mm thick.