AAAA Battery - Dimensions, Features, and Replacements
AAAA batteries are small, cylindrical batteries commonly used in small electronic devices like calculators, flashlights, laser pointers, game controllers, and similar.
Like similar, but larger, AA and AAA batteries, AAAA batteries also come in different chemistries, offering different performances and features, but also different prices.
Published: November 30, 2020.
AAAA Battery Features and Specifications
AAAA batteries feature physical dimensions of (D x H) 8.3 x 42.5 mm (~0.3268 x 1.6732 inches) and it is very similar to:
- AAA battery (D x H): 10.5 x 44.5 mm,
- AA battery (D x H): 14.5 x 50.5,
except that the AAAA is generally smaller and relatively longer/thinner.
AAAA batteries features several labels, including LR8D425 (alkaline, IEC standard), R8D425 (zinc-carbon, IEC standard), KR8D425 (NiCd, IEC standard), HR8D425 (NiMH, IEC standard), 25A (ANSI standard), MX2500, LR61, Mini and many others, but practically all manufacturers use 'AAAA' label to avoid any confusion.
Note: many manufacturers label their AAAA batteries as LR61 batteries, although the actual LR61 battery is somewhat shorter (~3.5 mm, ~0.14 inches) than the AAAA battery. LR61 batteries are rarely used on their own - they are commonly used to form larger batteries, for example, 6V (4LR61) and 9V (6LR61) batteries.
The following chart lists the most common chemistry types of the AAAA batteries:
| Chemistry | Zinc-Carbon | Alkaline | Nickel-Cadmium | Nickel Metal Hydride | Lithium-Ion |
| Rechargeable | No | No | Yes | Yes | Yes |
| Typical Voltage | 1.5 V | 1.5 V | 1.2 V | 1.2 V | 3.6 V |
| Typical Capacity | 300 mAh | 400 - 600 mAh | 200-400 mAh | 350 - 500 mAh | 170 mAh |
Non-Rechargeable AAAA Batteries
The most common AAAA batteries are non-rechargeable alkaline AAAA batteries with a nominal voltage of 1.5 volts and a capacity of 400-600 mAh, sometimes even more.
Actual capacity depends on the discharge current and other discharge conditions. For example, the Energizer AAAA battery (PDF datasheet, opens in the new window) features a capacity of:
- ~250 mAh, when being discharged with 300 mAh current,
- ~325 mAh, when being discharged with 200 mAh current,
- ~475 mAh, when being discharged with 100 mAh current,
- ~680 mAh, when being discharged with 10 mAh current.
Zinc-carbon AAAA batteries are cheaper than alkaline AAAA batteries, but most manufacturers offer alkaline AAAA batteries due to the better performances, including more stable output voltage, larger capacity, and longer shelf life (up to 5 years).
Rechargeable AAAA Batteries
Rechargeable AAAA batteries mostly come as Nickel Cadmium (NiCd), Nickel Metal Hydride (NiMH), and Lithium-ion batteries.
Nickel Cadmium (NiCd) AAAA batteries are rarely used today due to the cadmium, which is heavy metal and toxic pollutant.
NiCd batteries have very low internal impedance and are able to provide large currents easily. However, they also feature a relatively large self-discharge rate, have a very strong memory effect, support less charging/discharging cycles than NiMH batteries, and generally have a smaller capacity.
Also, both NiCd and NiMH batteries feature a nominal voltage of 1.2 volts - some devices intended for 1.5V zinc-carbon or alkaline batteries don't operate reliably when powered by 1.2 volts NiCd and/or NiMH batteries.
Actual capacity depends on the discharge conditions and age of the battery, but it is generally smaller than the capacity of NiMH batteries.
Advances in chemistry and the fact that NiCd batteries contain cadmium make the NiMH preferred choice over NiCd batteries.
Nickel Metal Hydride (NiMH) batteries support a larger number of charging/discharging cycles than NiCd batteries and practically have no memory effect. Also, NiMH batteries feature lesser self-discharge rage and larger capacity.
Since they don't contain toxic heavy metals, NiMH batteries are preferred 1.2 volts chemistry for the AAAA (and other) batteries.
Depending on the exact chemistry, Lithium-ion AAAA batteries feature nominal voltage between 3.2 and 3.7 volts and capacity between 150 and 200 mAh.
However, lithium-ion AAAA batteries are not as common as alkaline and NiMH batteries and are rarely used.
Note: due to the much larger voltage (3.2 - 3.7 vs 1.2 - 1.5 volts) never replace alkaline or NiMH AAAA (or any other similar) battery with lithium-ion battery, unless specifically stated by the device manufacturer that such replacement is allowed and that it will not harm the device.
AAAA Battery vs 4LR61 (J-Type) 6V Battery
4LR61 (J-Type) battery is 6 volts flat battery featuring physical dimensions of (H x L x W) 48.5 x 35.6 x 9.18 mm and it is shaped that it can fit the battery compartment only the one (proper) way.
Internally, 4LR61 battery contains 4 LR61 batteries connected in series. Although LR61 batteries are somewhat shorter than AAAA batteries (~3.5 mm, 0.14 inches), some devices support the use of plastic battery holders for four AAAA (8.3 x 42.5 mm) batteries.
AAAA Battery vs 6LR61 (E-Type) 9V Battery
6LR61 (E-Type, 9-volt, PP3) battery is a 9 volts flat battery featuring physical dimensions of (H x L x W) 48.5 x 26.5 x 17.5 mm.
Internally, the 6LR61 battery often contains six LR61 batteries connected in series, hence the name. Again, some devices come with a battery holder supporting the use of six AAAA batteries instead of one 6LR61 battery.
Long Story Short: If You are looking for a new non-rechargeable AAAA battery, go for an alkaline AAAA battery from some of the most reputable brands and check comments and reviews.
When looking for rechargeable AAAA batteries, be sure to note the exact chemistry type, capacity, and drain current and go for the battery of the same chemistry that features the same or better capacity and supports the same or larger drain currents.
