Energizer 321 Silver Oxide Button Cell Batteries (10 Pack)

The Energizer 321 is a 1.55V silver oxide button cell battery supplied in a 10-pack. The 321 designation (also known as SR616SW in IEC notation) identifies a 6mm diameter, 1.6mm height cell format used in wristwatches, calculators, medical instruments, fitness trackers, hearing aids and remote key fobs. Silver oxide chemistry provides a stable voltage curve across the battery's discharge cycle, maintaining consistent performance until the cell is depleted rather than gradually fading like alkaline alternatives.

Designed for devices requiring precision timing or low-drain continuous operation, the 321 delivers a flat 1.55V output that keeps quartz watch movements accurate and calculator displays crisp. The leak-resistant construction uses a nickel-plated steel case crimped to a precision tolerance, reducing the risk of electrolyte leakage that can corrode circuit boards in watches and medical devices. Each cell weighs approximately 0.01kg and stores well — the 10-pack format suits users replacing multiple watch batteries or stocking spares for medical equipment.

The Energizer 321 fits devices specifying 321, SR616SW, SR65, V321, D321, 280-73, SB-AF or GP321 batteries. The silver oxide chemistry typically provides 2-3 years of service life in a standard quartz wristwatch drawing 1-2 microamps, considerably longer than alkaline equivalents. The 10-pack blister format keeps unused cells sealed until needed, maintaining freshness during storage.

What devices use a 321 battery?

The 321 (SR616SW) is used in wristwatches, small calculators, medical instruments such as glucose monitors, fitness trackers, hearing aids and remote car key fobs. Check your device's battery compartment or manual for the exact cell size required.

What's the difference between silver oxide and alkaline button cells?

Silver oxide cells like the 321 maintain a stable 1.55V output throughout their discharge cycle, making them suitable for precision timing devices such as quartz watches. Alkaline button cells start at 1.5V but their voltage drops gradually during use, which can cause watches to lose accuracy before the battery is fully depleted.

How long does a 321 battery last?

In a typical quartz wristwatch drawing 1-2 microamps, a 321 silver oxide cell provides approximately 2-3 years of service. In higher-drain devices such as fitness trackers or hearing aids, the lifespan shortens depending on usage patterns and power draw.

Can I use SR616SW instead of 321?

Yes. 321 and SR616SW are different naming conventions for the same cell. Other equivalent designations include SR65, V321, D321, 280-73, SB-AF and GP321. All refer to a 6mm diameter, 1.6mm height silver oxide button cell.