Which Are Better Silver-Oxide or Alkaline Batteries?
Silver-oxide and alkaline button/coin cells feature exactly the same dimensions and very similar nominal voltage, but they differ in capacity, self-discharge rate, operating temperature range, etc.
Many devices powered by button/coin cells come with alkaline batteries and many people wonder if they can be replaced with silver-oxide batteries...
Published: April 29, 2022.
Silver-Oxide vs Alkaline Batteries
Alkaline batteries feature a nominal voltage of 1.5V, a cutoff voltage of 0.9V, and a typical annual self-discharge rate of 10-15% when being stored @20-25°C - on average, alkaline batteries feature a shelf life of 2-3 years when stored at room temperature.
On the other hand, silver-oxide batteries feature a nominal voltage of 1.55V, a cutoff voltage of 1.2V, and a typical annual self-discharge rate of 2-10% when being stored @20-25°C - on average, silver-oxide batteries feature a shelf life of 2-5 years, sometimes even more, when stored at room temperature.
However, it is very important to emphasize that the actual voltage of silver-oxide batteries is very stable during the discharge time, and only at the very end of the battery life, the output voltage drops from 1.50-1.55V (depending on the temperature, current, battery age, etc.) to 1.2V.
Also, silver-oxide batteries often come in low-drain and high-drain versions.
Low-drain versions feature a very low self-discharge rate, usually in the 2-4% range (annually), and are intended for devices that don't require high-drain pulses.
High-drain silver-oxide batteries feature a self-discharge rate in the 5-10% range (annually) but can withstand high current pulses very well.
Such high-drain batteries are intended for devices like remote controls, key chain flashlights, car key fobs, digital watches with LED lights and alarms, and similar.
In order to prevent confusion among their users and to help them choose the right silver-oxide battery, thanks to the advances in technology, many brands are switching to multi-drain batteries which feature a low self-discharge rate and are able to provide high current pulses when required.
Also, silver-oxide batteries under the same conditions, on average, feature 10-40% larger capacity - due to the more stable output voltage and larger capacity, silver-oxide batteries feature ~15-50% better energy density when compared with the alkaline batteries.
So, if You are wondering should You replace your alkaline batteries with silver-oxide ones, the answer is - it depends. Silver-oxide batteries tend to cost a little bit more, but personally, the performance differences justify the price difference.
Alkaline and Silver-Oxide Batteries Safety Issues
While modern alkaline and silver-oxide batteries don't contain toxic metals like mercury, cadmium, and similar, if they get swallowed they may cause electrolytic reactions that may cause chemical burns.
If they get swallowed by kids or pets (or anybody else), contact the nearest emergency center, explain what happened, and act according to their instructions.