1. Same size, different chemistry
An SR44 (silver oxide) and an LR44 (alkaline) are both about 11.6 mm wide and 5.4 mm thick. They fit the same slot, but they aren’t the same battery.
2. Steady voltage
A silver oxide cell gives about 1.55 volts and keeps that level until it’s nearly empty. An alkaline gives about 1.5 volts, and its voltage falls more gradually as it’s used.
3. Where silver oxide suits you
Watches, calculators and precision gadgets, where steady power and accurate timing matter. They cost more per cell.
4. Where alkaline is fine
Toys, laser pointers, thermometers and other devices that don’t depend on exact timing. An alkaline is the cheaper choice for these.