Match My Battery

Silver oxide

321 battery replacement and equivalents

321 is a 1.55 V silver oxide button battery measuring 6.8 × 1.65 mm. Match the complete specification before treating another marking as a replacement.

SR616SWD321
Nominal voltage
1.55 V
Dimensions
6.8 × 1.65 mm
Chemistry
Silver oxide

321 specifications

Canonical code321
Formbutton
RechargeableNo
Drain markinglow

Typical applications

  • Analog watches
  • calculators
  • low-drain instruments

Replacement decision

Resolve the original marking to this profile, then confirm nominal voltage, chemistry, dimensions, polarity and any drain or terminal suffix. Capacity alone does not establish interchangeability.

Reviewed comparisons

321 vs 377Same diameter · different height321 vs 339Same diameter · different height321 vs 364Same diameter · different height321 vs 376Same diameter · different height

Technical sources

  1. International Electrotechnical Commission — IEC 60086-1:2026 — Primary batteries, general requirements

    Primary-battery nomenclature, form, fit, function, terminal and electrochemical-system framework.

  2. Energizer — Battery Replacement Guide

    Cross-reference codes and manufacturer guidance to replace the same size and type together.

  3. Duracell — Battery Cross Reference Chart

    Independent manufacturer cross-reference families and corresponding product numbers.

  4. Duracell — Battery chemistry technical bulletins

    Alkaline, lithium-manganese-dioxide, zinc-air and silver-oxide chemistry behavior.