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.

Updated: January 6, 2024.

 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:

Non-Rechargeable AAAA Batteries Comparison Table

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.

Some of the most common AAAA batteries with their most important features and specifications are given in the following comparison table:

As one can see, the 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 their 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 a 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 fewer 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-volt 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 a 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. Some of the most popular NiMH AAAA batteries are (Amazon links, the links open in the new windows):

• ANVOW NiMH 1.2V 400mAh AAAA Batteries + Charger
• EBL NiMH 1.2V 400mAh AAAA Batteries + Charger
• ANVOW NiMH 1.2V 400mAh AAAA Batteries

Depending on the exact chemistry, Lithium-ion AAAA batteries feature a nominal voltage between 3.2 and 3.7 volts and a 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 a 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 so that it can fit the battery compartment only in one (proper) way.

Internally, 4LR61 batteries contain 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

The 6LR61 (E-Type, 9-volt, PP3) battery is a 9-volt flat battery with the physical dimensions (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.

Typical Uses of AAAA Batteries

AAAA batteries, smaller and slimmer than the more common AA and AAA types, find their niche in a variety of compact electronic devices.

Non-rechargeable alkaline AAAA batteries are favored for their longer shelf life and stability, making them ideal for low-drain applications like laser pointers, LED penlights, wireless mice, remote devices, etc., where frequent battery replacement is not practical.

On the other hand, rechargeable lithium AAAA batteries offer the advantage of being eco-friendlier and cost-effective over time, suitable for devices with higher energy demands and frequent use, such as certain medical equipment, some cameras, and photo equipment, high-end audio devices, some headsets, etc.

The choice between these two types depends on the specific needs of the device and the user's preference for convenience versus sustainability.

How to Store AAAA Batteries

Most alkaline AAAA batteries feature a shelf life of 3-5 years when stored at room temperature, away from direct sunlight.

To increase their shelf life/storage time, one can keep them in somewhat cooler areas, even in the fridge, although they should be kept above the freezing point.

When the batteries are kept in such conditions, before their use, they must be at room temperature for 24h to "recover."

Personally, if unsure, always keep your AAAA batteries at room temperature and/or check the recommendations by their manufacturers.

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.

Most popular AAAA batteries are alkaline, and lithium 1.5V AAAA batteries, and some of the most popular models are (Amazon links, the links open in the new window):

• Duracell AAAA 1.5V Ultra Photo Alkaline Batteries
• Energizer AAAA 1.5V Alkaline Batteries

When replacing old batteries, be sure to dispose of them properly.