Match My Battery

How to measure a battery safely

Use clean calipers to narrow the catalog, then confirm the marking, voltage and terminal layout.

Reviewed
2026-08-25
Sources
2
Reading time
4 minutes

Measure the widest and tallest points

Power the device down and remove the cell before measuring. For a round cell, record diameter and height in millimeters; for a rectangular pack, record width, depth and height without bridging the terminals.

Record the marking before cleaning it

Write down every letter, number and suffix before relying on a caliper. A measurement cannot reveal whether a cell is alkaline, silver oxide, zinc air, lithium or rechargeable.

Use the result as a shortlist

Compare the measured envelope with the reviewed dimension group, then return to the original code, voltage, chemistry, polarity and terminal arrangement. The size finder deliberately reports candidates rather than an automatic replacement.

Decision guide

ProfilesFirst normalized profileSecond normalized profilecompareBatteries decision
LR621 vs LR626LR621
1.5 V · Alkaline manganese dioxide · 6.8 × 2.1 mm		LR626
1.5 V · Alkaline manganese dioxide · 6.8 × 2.6 mm		Same diameter · different height

Use the specified height; do not rely on contact spring travel.

  • Diameter matches.
  • Height and capacity envelope differ.
AAA vs HR03AAA
1.5 V · Alkaline manganese dioxide · 10.5 × 44.5 mm		HR03
1.2 V · Nickel-metal hydride · 10.5 × 44.5 mm		Same size · different voltage

Use the exact voltage and battery system specified by the device manufacturer.

  • The physical envelope matches.
  • Nominal voltage differs: 1.5 V versus 1.2 V.
  • Chemistry also changes from Alkaline manganese dioxide to Nickel-metal hydride.
395 vs LR927395
1.55 V · Silver oxide · 9.5 × 2.7 mm		LR927
1.5 V · Alkaline manganese dioxide · 9.5 × 2.7 mm		Same fit · different chemistry

Use only when the device maker explicitly approves both chemistry systems.

  • The physical envelope matches.
  • Nominal voltage is close.
  • Chemistry and discharge behavior differ.

Limits and safety checks

This guide narrows a battery decision but does not override the device manufacturer’s current manual, charging instructions or safety guidance.

Continue with: Open the size finder Check an AAA dimension profile Why size is not equivalence

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. U.S. Consumer Product Safety Commission — Button Cell and Coin Battery Safety

    Coin-cell ingestion and household handling safety boundary.