Silver oxide vs alkaline batteries
Two button cell chemistries in shared sizes: silver oxide at 1.55 V with a flat discharge curve and more capacity, alkaline at 1.5 V and far cheaper.
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In button cells these are the two choices, and they are the same size, so both will fit. Silver oxide holds an almost constant voltage until the moment it dies and stores around half again as much energy. Alkaline starts slightly lower and fades steadily from the first day. For a watch, a light meter or callipers — anything where a drifting voltage shows up as a wrong reading — buy silver oxide. For a toy or a calculator, alkaline costs a fraction as much and does the job.
- Verdict:
- Silver oxide for precision, alkaline for price
Side by side
| Specification | Silver oxide | Alkaline |
|---|---|---|
| Nominal voltage | 1.55 V | 1.5 V |
| Discharge curve | Nearly flat | Slopes from the start |
| Capacity (LR44 size) | 150–200 mAh | 110–130 mAh |
| Cost | Three to five times more | Low |
| Code prefix | SR | LR |
| Best for | Watches, meters, instruments | Toys, calculators, thermometers |
The flat curve is what you pay for
A silver oxide cell holds close to 1.55 V for nearly its whole life then drops off quickly. An alkaline cell of the same size begins sagging immediately. In a watch that means it keeps time to the end rather than running slow for weeks.
They share sizes deliberately
SR44 and LR44 are the same 11.6 × 5.4 mm cell in two chemistries, which is why a device can accept either. The 0.05 V difference is negligible for most things and decisive for a few.
Reading the code
The first letter gives the chemistry: S for silver oxide, L for alkaline. If you can read that one letter you can tell the two apart on any shelf, whatever the brand's own number says.
Watch repairers default to silver oxide
Ask a jeweller to change a watch battery and you will get a silver oxide cell. It is not upselling: a watch is a low-drain device that runs for years, which is exactly where the flat discharge curve and the better leak resistance pay off.
Leak resistance is the quiet advantage
Alkaline button cells left flat in a device can vent and corrode contacts, and in a watch that means damage to a movement worth far more than the cell. Silver oxide is markedly less prone to it, which matters in anything you would rather not open in a hurry.
Where you cannot substitute
Some vintage cameras and light meters were calibrated around a mercury cell at 1.35 V that is no longer sold. Silver oxide at 1.55 V is the usual modern stand-in, but the meter will read high unless an adapter with a voltage-dropping diode is fitted.
Check before you swap. Batteries with similar dimensions are not always interchangeable. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.
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Silver oxide vs alkaline batteries: common questions
What is the difference between Silver oxide and Alkaline?
In button cells these are the two choices, and they are the same size, so both will fit. Silver oxide holds an almost constant voltage until the moment it dies and stores around half again as much energy. Alkaline starts slightly lower and fades steadily from the first day. For a watch, a light meter or callipers — anything where a drifting voltage shows up as a wrong reading — buy silver oxide. For a toy or a calculator, alkaline costs a fraction as much and does the job.
Which should I choose, Silver oxide or Alkaline?
Silver oxide for precision, alkaline for price. Two button cell chemistries in shared sizes: silver oxide at 1.55 V with a flat discharge curve and more capacity, alkaline at 1.5 V and far cheaper.
Nominal voltage — how do they compare?
Silver oxide: 1.55 V. Alkaline: 1.5 V.