What is equivalent to a HR03?

HR03, HR11/45, 1.2H1, NH12, Eneloop AAA, Ni-MH AAA — all the same 1.2 V cell under different manufacturer codes.

Can I use a 10440 instead of a HR03?

The AAA-sized lithium-ion cell at 3.7 V. Different chemistry, different charger, more than three times the voltage.

Is the HR03 rechargeable?

Yes. Use a charger made for its chemistry and never substitute a primary cell of the same size.

HR03 battery

What replaces a HR03

HR03, HR11/45, 1.2H1, NH12, Eneloop AAA, Ni-MH AAA

1.2 V nickel-metal hydride, 10.5 × 44.5 mm (diameter × height)

The HR03 is a rechargeable 1.2 V nickel-metal hydride cylindrical. The codes below are the same physical cell sold under different manufacturer names, and any of them will fit.

Specification

IEC designation: HR03
ANSI / NEDA: 1.2H1
Nominal voltage: 1.2 V
Chemistry: Nickel-metal hydride
Size: 10.5 × 44.5 mm (diameter × height)
Typical capacity: 800 mAh
Rechargeable: Yes

Codes that mean the same battery

Different manufacturers, one physical battery. Voltage, chemistry and dimensions all match.
Code	Fits?
HR03	Yes — same cell
HR11/45	Yes — same cell
1.2H1	Yes — same cell
NH12	Yes — same cell
Eneloop AAA	Yes — same cell
Ni-MH AAA	Yes — same cell

Codes that look close but are not

Code	Why it is not a substitute
10440	The AAA-sized lithium-ion cell at 3.7 V. Different chemistry, different charger, more than three times the voltage.
Alkaline AAA	1.2 V rather than 1.5, with the same caveats as AA about devices that judge charge by voltage.

Where it turns up

Remote controls and small torches
Wireless keyboards and mice
Cordless phone handsets
Solar garden lights

Typically 750–950 mAh, against roughly 1150 mAh for an alkaline AAA at low drain.

Common questions

What is equivalent to a HR03?: HR03, HR11/45, 1.2H1, NH12, Eneloop AAA, Ni-MH AAA — all the same 1.2 V cell under different manufacturer codes.
Can I use a 10440 instead of a HR03?: The AAA-sized lithium-ion cell at 3.7 V. Different chemistry, different charger, more than three times the voltage.
Is the HR03 rechargeable?: Yes. Use a charger made for its chemistry and never substitute a primary cell of the same size.

LR6 battery 1.5 V alkaline
LR03 battery 1.5 V alkaline
ICR18650 battery 3.6 V lithium-ion (rechargeable)
LR20 battery 1.5 V alkaline
HR6 battery 1.2 V nickel-metal hydride
LR14 battery 1.5 V alkaline
CR17345 battery 3 V lithium (primary)
8LR932 battery 12 V alkaline
FR6 battery 1.5 V lithium (primary)
INR21700 battery 3.6 V lithium-ion (rechargeable)
4LR44 battery 6 V alkaline
CR15H270 battery 3 V lithium (primary)

Sources

Typical range compiled from manufacturer specifications — At One Place

How these figures are compiled and checked