LR44 vs SR44: the same 11.6 × 5.4 mm size does not make them the same battery
LR44 and SR44 button cells can fit the same physical envelope, but the prefixes identify different chemistries. LR44 is an alkaline button cell with a 1.5 V nominal rating; SR44 is a silver-oxide button cell commonly rated at 1.55 V. That difference matters more than the shared size.
LR44 and SR44 at a glance
| Specification | LR44 | SR44 |
|---|---|---|
| Chemistry family | Alkaline button | Silver oxide |
| Model-prefix meaning | LR = alkaline, round | SR = silver oxide, round |
| Nominal voltage | 1.5 V | 1.55 V |
| Nominal diameter | 11.6 mm | 11.6 mm |
| Nominal height | 5.4 mm | 5.4 mm |
| Common branded/cross-reference examples | A76, AG13, G13A, L1154, 1166A | 357/303 and other SR44-family markings |
| Voltage behavior | Alkaline discharge profile | Silver oxide is commonly chosen where stable voltage is useful |
Cross-reference labels are manufacturer and market dependent. Treat the chemistry designation and the device maker's requirement as more important than a retailer's generic “equivalent” list.
The prefix is the chemistry clue
Panasonic's battery-model FAQ explains that the first letter identifies battery type and that LR denotes alkaline batteries while SR denotes silver-oxide batteries. The second letter, R, indicates a round cell. That means LR44 and SR44 are not two names for one chemistry even though the package dimensions match.
The shared “44” size designation is useful for physical compatibility, but it cannot tell you the electrochemical system. This is the same general lesson as the CR2032 versus BR2032 guide: a similar size code does not erase the information carried by the prefix.
Why 1.50 V versus 1.55 V is not the whole story
The nominal-voltage difference is small: Panasonic lists LR44 at 1.5 V and its current SR44P reference at 1.55 V. It would be easy to conclude that the two cells are therefore practically identical. But nominal voltage is only one characteristic of a battery.
Panasonic's educational material describes silver-oxide batteries as having stable voltage and long life, and notes their use in watches and precision equipment. The same source describes alkaline button batteries as a lower-cost 1.5 V option used in products such as toys, calculators and cameras. Those descriptions point to different design priorities even before a particular device's load is considered.
A device may care about how voltage changes during discharge, not only the fresh-cell voltage. Precision timing, measurement or display circuits can therefore have a different tolerance for substitution than a simple low-cost toy or light.
Do not compare the mAh numbers without the test conditions
Energizer's A76 datasheet identifies the cell as IEC-LR44 and gives a typical capacity of 150 mAh under a 7.5 kΩ continuous-drain test to a 0.9 V cutoff. Energizer's 357/303 silver-oxide datasheet identifies that product as IEC-SR44 and also gives a typical capacity of 150 mAh, but under a 6.8 kΩ continuous-drain test to a 1.2 V cutoff.
Those two “150 mAh” numbers are therefore not a clean head-to-head battery-life comparison. The load resistance and end voltage are different. Capacity depends on the test method, load, temperature and cutoff voltage, so equal printed mAh values do not prove equal runtime in a real device.
What do A76 and AG13 mean?
Panasonic's current LR44 cross-reference table maps LR44 to Energizer A76 and also lists AG13, G13A, L1154 and 1166A among other market references. That is useful when a device or old battery uses a non-IEC label.
The important limitation is that AG13 belongs on the LR44 side of this comparison in Panasonic's table. It should not be treated as a chemistry-neutral synonym for every 11.6 × 5.4 mm button cell. If a listing says “AG13 / LR44 / SR44 / 357 all the same,” it is compressing distinct chemistry designations into a physical-size shortcut.
Energizer's own A76 sheet explicitly designates A76 as IEC-LR44, while its 357/303 sheet designates that product as IEC-SR44. Those are more useful clues than a marketplace title containing a long string of battery numbers.
Can SR44 replace LR44?
Sometimes equipment documentation or the manufacturer may permit both chemistries, but that permission should come from the device maker rather than from the fact that the cells fit the same holder. Panasonic's general battery-use guidance notes that certain silver-oxide batteries can be used with devices compatible with alkaline button batteries, while also warning that equipment conditions matter. That is a compatibility exception, not proof that the two designations are identical.
If the device specifies only LR44, use LR44 unless the manual or manufacturer explicitly gives an allowed silver-oxide equivalent. If it specifies SR44, use SR44 or an explicitly approved SR44-family cross reference rather than assuming a cheaper alkaline cell is equivalent.
Can LR44 replace SR44?
The same caution applies in the other direction. An LR44 can occupy the same nominal space, but it does not reproduce the silver-oxide chemistry or its voltage behavior. A device designed around a stable-voltage silver-oxide cell may behave differently as an alkaline cell discharges.
For a watch, measuring device, calculator, camera accessory or other small electronic product, the battery door and manual are better evidence than a retailer's “fits the same” claim.
A practical replacement workflow
- Read the original marking exactly. Record LR44, SR44, A76, 357/303 or the other printed designation before discarding the old cell.
- Translate branded names carefully. Use a manufacturer cross-reference table, not a marketplace keyword list.
- Preserve the chemistry when possible. LR and SR identify different battery systems even at the same size.
- Check nominal voltage. LR44 is typically 1.5 V; SR44 is typically 1.55 V.
- Do not rank unlike datasheets by mAh alone. Check the load and cutoff voltage used for the capacity test.
- Let the device manual decide substitutions. Physical fit is necessary but not sufficient evidence of compatibility.
Related battery guides
- CR2032 vs BR2032 is another same-size comparison where the chemistry prefix changes the electrical behavior.
- 1.5V alkaline vs 1.2V NiMH AA shows why a shared physical form factor still does not make two battery chemistries electrically identical.
Primary sources
- Panasonic Energy — Alkaline Button Technologies, for LR44 voltage, 11.6 × 5.4 mm dimensions and the LR44/A76/AG13-family cross-reference table.
- Panasonic Energy — Dry Batteries FAQ, for the LR and SR model-prefix meanings.
- Panasonic Energy — Simple battery structure, for the 1.5 V alkaline-button and 1.55 V silver-oxide descriptions and their general performance positioning.
- Panasonic Energy — How to use batteries, for the manufacturer's general compatibility guidance between certain silver-oxide and alkaline button batteries.
- Panasonic Energy Japan — SR44P cross-reference entry, for the cited 1.55 V rating and 11.6 × 5.4 mm dimensions.
- Energizer — A76 product datasheet, for the IEC-LR44 designation, chemistry, nominal voltage, dimensions and capacity-test conditions.
- Energizer — 357/303 product datasheet, for the IEC-SR44 designation, silver-oxide chemistry, nominal voltage, dimensions and capacity-test conditions.
Bottom line
LR44 and SR44 share a common button-cell size, but they do not share a chemistry. LR44 is alkaline; SR44 is silver oxide. Use the exact device-specified designation, interpret A76 and AG13 as LR44-family references rather than universal “44-size” synonyms, and compare capacity figures only when their test conditions are comparable.