Match My Battery

Alkaline button

LR521 battery replacement and equivalents

LR521 is a 1.5 V alkaline manganese dioxide button battery measuring 5.8 × 2.1 mm. Match the complete specification before treating another marking as a replacement.

AG0
Nominal voltage
1.5 V
Dimensions
5.8 × 2.1 mm
Chemistry
Alkaline manganese dioxide

LR521 specifications

Canonical codeLR521
Formbutton
RechargeableNo
Drain markingNot specified

Typical applications

  • Toys
  • calculators
  • small lights
  • simple electronics

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

LR521 vs LR516Same 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.