LR41 vs SR41
The LR41 and the 392 fit the same battery compartment: both measure 7.9 mm across and 3.6 mm tall. The LR41 is a 1.5 volt alkaline cell holding 25 to 32 mAh; the 392 is the silver-oxide SR41W at 1.55 volts with about 45 mAh and a much flatter discharge.
| LR41 | SR41 | |
|---|---|---|
| Chemistry | Alkaline (Zn/MnO2) | Silver oxide (Ag2O) |
| Voltage | 1.5 V | 1.55 V |
| Diameter | 7.9 mm | 7.9 mm |
| Height | 3.6 mm | 3.6 mm |
| Capacity | 25-32 mAh | 42-45 mAh |
| Also sold as | AG3, LR736, L736, 192 | 392, 384, SR736, SR41W (392) |
This pairing matters mostly because of digital thermometers, which made the LR41 a household name. For a thermometer used occasionally, the cheap alkaline cell is genuinely fine: each reading draws current for under a minute, and even a modest cell lasts years. The multipacks sold as AG3 are the same battery again.
The 392 earns its premium in three situations. Watches, where the flat 1.55 volts keeps time accurate for two to three years instead of a drifting year on alkaline. Medical devices used daily, where the extra capacity and stable output reduce mid-measurement surprises. And anything stored long-term, because silver-oxide cells self-discharge more slowly and are markedly less likely to leak; a leaked LR41 destroys thermometer contacts with depressing regularity.
One naming note: the 384 is the same silver cell tuned for low drain (SR41SW), preferred for simple analog watches. The 392 is the high-drain version. Either replaces an LR41 without any fitting concern.