Match My Battery

AAA vs HR03: battery compatibility

A reviewed side-by-side decision based on form, fit, electrical specification and application limits.

Verdict
Same size · not an automatic replacement
Device approval
Not assessed
Reviewed
2026-10-04
Same size · not an automatic replacement

AAA (LR03) and HR03 differ in chemistry and nominal voltage

LR03 alkaline is nominally 1.5 V; HR03 NiMH is nominally 1.2 V. Both use the AAA envelope. HR03 can be a rechargeable alternative when the device manual permits NiMH; the nominal-voltage difference alone is not a universal prohibition or an approval.

Use HR03 only when the device manual permits NiMH. Do not assume that every device accepting AAA alkaline cells supports it.

SpecificationAAAHR03
Dimensions10.5 × 44.5 mm10.5 × 44.5 mm
Nominal voltage1.5 V1.2 V
ChemistryAlkaline manganese dioxideNickel-metal hydride
RechargeableNoYes
Typical useHousehold electronics, lights, remotesRechargeable household devices, cameras, controllers
View AAA profile View HR03 profile

About Confidence: this is a fixed score attached to a comparison rule in the catalog. It is not a probability of working, a measured success rate, or device approval. Read the verdict and its reasons; a high score can accompany a non-equivalence verdict.

AAA and HR03 questions

Can HR03 replace an AAA alkaline LR03 battery?

HR03 is not an exact LR03 alias. It can be a rechargeable alternative when the device manual permits NiMH, but matching the AAA size alone does not establish compatibility with a particular device.

Why does HR03 say 1.2 V while LR03 says 1.5 V?

These are different nominal voltages for NiMH and alkaline chemistry. Panasonic explains that eneloop NiMH can operate in many devices normally using dry batteries because the devices accommodate a discharge-voltage range. That guidance does not certify every AAA device; follow its manual.

Can alkaline and NiMH cells be mixed or charged together?

Do not mix alkaline and NiMH cells in a device battery set. Never recharge primary alkaline cells. Use a compatible NiMH charger for HR03 and follow the battery, charger and device instructions.

Why this verdict

  • The listed dimensions match: 10.5 × 44.5 mm.
  • Alkaline and NiMH have different nominal voltages and discharge behavior.
  • Device requirements, rather than physical fit alone, determine whether NiMH is permitted.

What to verify in the device

Check the original compartment label, the current manual, polarity, terminal style and whether the device explicitly permits a chemistry or rechargeable alternative.

Sources for these profiles

  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.

  5. Panasonic Energy — eneloop FAQ: use in dry-battery devices and mixed-battery precautions

    Product-family guidance on 1.2 V NiMH use and matched sets; not approval of an unspecified device.

  6. Energizer — Nickel Metal Hydride Handbook and Application Manual (2018)

    Dated manufacturer context for NiMH discharge behavior, charging and device-design limits.