4LR44 vs 4SR44
The 4LR44 and the 4SR44 are the same shape, 13 mm across and 25.2 mm long, built from four button cells stacked in a tube. The 4LR44 is alkaline at 6 volts with 110 to 150 mAh. The 4SR44 is silver oxide at 6.2 volts with 150 to 180. The chemistry is the whole story.
| 4LR44 | 4SR44 | |
|---|---|---|
| Chemistry | Alkaline (4-cell stack) | Silver oxide (Ag2O), 4-cell stack |
| Voltage | 6 V | 6.2 V |
| Diameter | 13 mm | 13 mm |
| Height | 25.2 mm | 25.2 mm |
| Capacity | 110-150 mAh | 150-180 mAh |
| Also sold as | A544, PX28A, 476A, 4A76 | PX28, 544, V28PX, 4G13 |
Alias confusion comes first. The alkaline is sold as A544, PX28A, 476A, 4A76, V4034PX and L1325, while the silver version is sold as PX28, 544, V28PX and 28PX. Listings often present the same battery as several different products at several different prices, so read the chemistry code rather than the brand number. An L or LR means alkaline, an S or SR means silver oxide.
For dog training and bark collars, which buy most of today's supply, the cheaper alkaline 4LR44 is fine and is what most replacement multipacks contain. For vintage film cameras the calculus changes. Bodies with voltage-sensitive meters, such as the Canon AE-1, were designed around the silver cell's stable output, so the 4SR44 gives more accurate metering across the life of the battery. Cameras with bridge-type meters are less fussy and run happily on the alkaline.
A third option shares the form factor: the lithium 2CR1/3N, sold as 28L, at 6 volts with long shelf life and better cold performance. It is slightly narrower, so check the fit before committing. In a pinch, four LR44 button cells stacked in the tube deliver the same 6 volts and usually work.