AA Battery
Pronunciation:
Word type: Noun
Common forms: AA battery, AA cell, double-A battery, AA
Plural: AA batteries
Related terms: battery, cell, dry cell, rechargeable battery, alkaline battery, portable power source
1. Overview
An AA battery is a small, cylindrical battery used to provide electrical energy to portable electronic devices. It is one of the most widely recognized battery sizes in the world.
The name AA mainly describes the physical size and shape of the cell. It does not, by itself, tell us the battery’s chemical composition. AA batteries can be made using several different chemistries, including alkaline, zinc-carbon, lithium iron disulfide, and nickel-metal hydride (NiMH).
A typical AA cell is about 50.5 mm long and 14.5 mm in diameter, although exact dimensions have small manufacturing tolerances.
Most ordinary AA batteries used in household devices have a nominal voltage of around 1.5 volts. Rechargeable NiMH AA batteries normally have a nominal voltage of about 1.2 volts. Therefore, voltage depends on the chemistry rather than simply on the letters “AA.”
Quick facts
| Feature | Information |
|---|---|
| Full/common name | AA battery |
| Alternative name | Double-A battery |
| Shape | Cylindrical |
| Approx. diameter | 14.5 mm |
| Approx. length | 50.5 mm |
| Common alkaline voltage | 1.5 V |
| Common NiMH voltage | 1.2 V |
| IEC size designation | R6 for zinc-carbon; LR6 for alkaline |
| ANSI size number | 15 |
| Japanese designation | UM-3 |
| Rechargeable versions | Yes |
| Common chemistry | Alkaline |
| Typical uses | Toys, clocks, remotes, cameras, flashlights and many other devices |
The IEC designation R6 identifies a zinc-carbon AA-size cell, while LR6 identifies an alkaline AA-size cell. The size is also associated with ANSI number 15.
2. Definition of AA Battery
Simple definition
An AA battery is a standardized cylindrical electrochemical cell designed to supply electrical power to portable devices.
Dictionary-style definition
AA battery (noun): A standardized cylindrical dry cell, commonly used in portable electronic equipment, household appliances and toys, with a typical diameter of about 14 mm and a length of about 50 mm.
Merriam-Webster defines an AA battery as a battery typically used in small electronic devices and standardized at approximately 51 mm in length and 14 mm in diameter.
Technical definition
Technically, a single AA unit is more accurately called a cell because it contains one electrochemical cell. However, everyday English commonly calls it a “battery.” A device may use one AA cell or several AA cells connected together.
The distinction is:
- Cell: One electrochemical unit.
- Battery: Technically, an assembly of cells; in everyday speech, the term is also commonly used for a single consumer cell.
- AA: A physical size designation.
3. What Does AA Mean?
The letters AA identify a standardized battery size.
It is important not to interpret AA as a chemical formula. An AA battery may contain different electrochemical systems.
For example:
- LR6 = alkaline AA-size cell.
- R6 = zinc-carbon AA-size cell.
- FR6 = lithium iron disulfide AA-size cell.
- HR6 = nickel-metal hydride rechargeable AA-size cell.
- KR6 = nickel-cadmium rechargeable AA-size cell.
- ZR6 = nickel-zinc AA-size cell.
Thus, AA describes size, while the additional code helps identify chemistry and characteristics.
4. Pronunciation
The expression AA battery is normally pronounced:
“double-A battery”
The letters are pronounced individually rather than as a single word.
Example
“My wireless mouse needs two AA batteries.”
Here, AA functions as a modifier describing the size of the battery.
5. Definitions and Functions
An AA battery performs several important functions.
5.1 Electrical energy storage
A battery stores energy in chemical form. When connected to an electrical circuit, chemical reactions produce electrical energy.
5.2 Power supply
AA batteries supply power to devices that are designed for AA-size cells.
Common examples include:
- Remote controls
- Wall clocks
- Flashlights
- Toys
- Wireless keyboards
- Wireless mice
- Radios
- Portable audio equipment
- Some cameras
- Game controllers
- Small measuring instruments
- Electronic gadgets
5.3 Portable operation
AA batteries allow a device to operate without a direct connection to a wall outlet.
5.4 Backup power
Some devices use AA batteries as backup power when mains electricity fails.
5.5 Rechargeable energy source
Rechargeable AA cells, especially NiMH cells, can be charged and reused many times when used with an appropriate charger.
6. How an AA Battery Works
The basic principle is electrochemistry.
Inside a typical battery are several important components:
- Positive electrode
- Negative electrode
- Electrolyte
- Separator
- Current collectors
- Outer casing
- Positive and negative terminals
When the battery is connected to a circuit, chemical reactions create a difference in electrical potential between the two terminals.
Electrons then flow through the external circuit.
A simplified process is:
Chemical energy → Electrochemical reaction → Electron movement → Electrical energy
The exact chemical reactions depend on the battery type.
7. Main Types of AA Batteries
“AA” does not mean one particular battery chemistry.
7.1 Alkaline AA battery
Alkaline AA batteries are among the most common disposable AA batteries.
They generally use:
- Zinc
- Manganese dioxide
- Potassium hydroxide electrolyte
Alkaline batteries are called “alkaline” because their electrolyte is alkaline rather than acidic.
Advantages:
- Widely available
- Relatively inexpensive
- Good shelf life
- Suitable for many household devices
- Easy to replace
Disadvantage:
They are normally disposable and must be replaced after their useful charge is exhausted.
7.2 Zinc-carbon AA battery
Zinc-carbon batteries are an older battery chemistry.
Their IEC designation is commonly R6.
They are generally less expensive but often have lower capacity and performance than modern alkaline batteries.
They may be used in simple, low-drain devices.
7.3 Lithium iron disulfide AA battery
Lithium iron disulfide batteries are commonly designated FR6.
They are primary, or generally non-rechargeable, cells designed to provide high performance and relatively low weight.
They can be useful in devices that require good performance over a wide range of conditions.
7.4 Nickel-metal hydride AA battery
NiMH AA batteries are popular rechargeable cells.
They usually have a nominal voltage of approximately 1.2 V.
Their advantages include:
- Rechargeability
- Good capacity
- Reusability
- Reduced need for frequent disposable-cell replacement
NiMH cells are commonly designated HR6 in IEC nomenclature.
7.5 Nickel-cadmium AA battery
NiCd AA cells are rechargeable.
They were historically important in rechargeable electronics, although modern consumer applications have increasingly favored other chemistries.
The IEC designation is commonly KR6.
7.6 Nickel-zinc AA battery
NiZn batteries are rechargeable and typically have a nominal voltage higher than NiMH cells.
They can be useful in equipment that benefits from a voltage closer to that of disposable alkaline cells.
8. AA Battery Voltage
One common mistake is thinking that every AA battery has exactly the same voltage.
That is not true.
| Battery chemistry | Typical nominal voltage |
|---|---|
| Zinc-carbon | 1.5 V |
| Alkaline | 1.5 V |
| Lithium iron disulfide | 1.5 V |
| NiMH | 1.2 V |
| NiCd | About 1.2 V |
| NiZn | About 1.6–1.65 V |
| Some lithium-ion 14500 cells | About 3.6–3.7 V |
The final category deserves special attention. A 14500 lithium-ion cell may have approximately the same physical dimensions as an AA cell but is not automatically electrically equivalent to a normal AA battery. Its substantially higher voltage can damage equipment designed for ordinary AA cells.
Therefore:
Same size does not always mean same electrical compatibility.
Always follow the device manufacturer’s battery specifications.
9. AA Battery Capacity
Battery capacity is commonly measured in milliampere-hours (mAh).
For example, a rechargeable AA battery marked 2500 mAh can theoretically deliver 2500 mA for one hour under specified test conditions, or 250 mA for approximately ten hours.
Actual operating time depends on:
- Device current consumption
- Battery chemistry
- Temperature
- Discharge rate
- Battery age
- Battery condition
- Device efficiency
Therefore, a higher mAh rating does not always guarantee proportionally longer real-world performance.
10. Physical Structure
A typical AA battery contains a cylindrical body.
The two ends are:
- Positive terminal (+): Usually the raised button.
- Negative terminal (−): Usually the flat end.
The outer casing protects the internal components and helps maintain the required mechanical structure.
The approximate standardized size is:
| Measurement | Approximate value |
|---|---|
| Diameter | 14.5 mm |
| Length | 50.5 mm |
| Shape | Cylindrical |
Different standards and manufacturers allow small tolerances.
11. AA Battery vs AAA Battery
AA and AAA batteries are often confused.
| Feature | AA | AAA |
|---|---|---|
| Relative size | Larger | Smaller |
| Approx. diameter | 14.5 mm | 10.5 mm |
| Approx. length | 50.5 mm | 44.5 mm |
| Common use | Higher-power portable devices | Smaller, lower-drain devices |
| IEC alkaline code | LR6 | LR03 |
| Common voltage | 1.5 V alkaline | 1.5 V alkaline |
AAA batteries are physically smaller than AA batteries.
An AAA battery should not be substituted for an AA battery unless the device is specifically designed to accept it.
12. Etymology and History
The history of the AA size is connected to the development of standardized dry cells and portable electrical equipment.
The AA battery size was introduced by the American Ever Ready Company in 1907. It was already being used in equipment such as flashlights before formal standardization. The size was later incorporated into ANSI standard battery sizes in 1947.
Over time, different countries and manufacturers used different names for the same basic size.
Examples include:
- AA
- R6
- LR6
- UM-3
- 15
- Penlight
- Mignon
- HP7
- U7
- U12
These names reflect differences in national standards, chemistry and historical commercial naming.
The word battery itself has a much older history. In early electrical science, “battery” referred to a group or arrangement of cells. Modern everyday language often uses “battery” for a single consumer cell as well.
13. Grammar and Linguistic Usage
AA battery is a noun phrase.
Here:
- AA = size designation used as an adjective-like modifier.
- battery = head noun.
Singular
This device uses one AA battery.
Plural
This device uses two AA batteries.
Possessive
The AA battery’s voltage is approximately 1.5 volts.
Compound expressions
- AA battery holder
- AA battery charger
- AA battery compartment
- AA battery pack
- AA battery tester
- rechargeable AA battery
- alkaline AA battery
Common usage
Both AA battery and AA cell are used.
“AA battery” is more common in everyday consumer language, while “AA cell” is often preferred in technical discussions.
14. Spelling and Word Formation
The standard spelling is:
AA battery
Other forms include:
- AA batteries
- AA cell
- double-A battery
- double-A cell
Incorrect or less preferred forms
- A A battery
- aa Battery
- AA-Battery
The capitalization of AA is important because it represents a standardized letter designation.
The plural is formed by changing battery to batteries:
AA battery → AA batteries
15. Synonyms, Related Words and Antonyms
An exact synonym for “AA battery” is difficult because AA is a standardized size designation. However, several related expressions are commonly used.
| Category | Word or expression | Meaning |
|---|---|---|
| Common equivalent | Double-A battery | Same common battery size |
| Common equivalent | AA cell | Technical/common alternative |
| Related | Dry cell | General type of electrochemical cell |
| Related | Alkaline battery | A common AA chemistry |
| Related | Rechargeable battery | Battery designed for repeated charging |
| Related | NiMH cell | Common rechargeable AA chemistry |
| Related | R6 | IEC designation for zinc-carbon AA |
| Related | LR6 | IEC designation for alkaline AA |
| Related | HR6 | IEC designation for NiMH AA |
| Related | FR6 | IEC designation for lithium iron disulfide AA |
| Related | Battery cell | General electrochemical power unit |
| Contrast | AAA battery | Smaller standardized cylindrical cell |
| Contrast | C battery | Larger standardized cylindrical cell |
| Contrast | D battery | Larger cylindrical cell |
| Contrast | Coin cell | Small, flat, coin-shaped cell |
There is no perfect antonym for AA battery, because it is a physical size category rather than a quality or action.
16. Variants and Equivalents in Hindi
In Hindi, AA battery is commonly expressed as:
एए बैटरी
डबल-ए बैटरी
Other descriptive expressions include:
- एए सेल
- एए आकार की बैटरी
- रिचार्जेबल एए बैटरी
- क्षारीय एए बैटरी
Hindi example
इस रिमोट में दो एए बैटरियाँ लगती हैं।
Meaning:
This remote requires two AA batteries.
17. Variants and Equivalents in Odia
In Odia, common expressions include:
ଏଏ ବ୍ୟାଟେରୀ
ଡବଲ୍-ଏ ବ୍ୟାଟେରୀ
Other expressions include:
- ଏଏ ସେଲ୍
- ରିଚାର୍ଜେବଲ୍ ଏଏ ବ୍ୟାଟେରୀ
- ଆଲ୍କାଲାଇନ୍ ଏଏ ବ୍ୟାଟେରୀ
- ଏଏ ଆକାରର ବ୍ୟାଟେରୀ
Odia example
ଏହି ଟର୍ଚ୍ଚରେ ଦୁଇଟି ଏଏ ବ୍ୟାଟେରୀ ଲାଗେ।
18. Equivalents in Other Languages
Because AA is an international size designation, many languages simply use the English letters AA together with their local word for battery.
| Language | Common expression |
|---|---|
| English | AA battery / double-A battery |
| Hindi | एए बैटरी / डबल-ए बैटरी |
| Odia | ଏଏ ବ୍ୟାଟେରୀ / ଡବଲ୍-ଏ ବ୍ୟାଟେରୀ |
| Bengali | এএ ব্যাটারি |
| Marathi | एए बॅटरी |
| Gujarati | એએ બેટરી |
| Punjabi | ਏਏ ਬੈਟਰੀ |
| Tamil | ஏஏ பேட்டரி |
| Telugu | ఏఏ బ్యాటరీ |
| Kannada | ಎಎ ಬ್ಯಾಟರಿ |
| Malayalam | എഎ ബാറ്ററി |
| French | pile AA / batterie AA |
| Spanish | pila AA / batería AA |
| German | AA-Batterie |
| Portuguese | pilha AA / bateria AA |
| Italian | batteria AA |
| Japanese | 単3形電池 |
| Chinese | AA电池 |
| Korean | AA 배터리 |
| Arabic | بطارية AA |
| Russian | батарейка AA |
The exact local expression can vary according to country and technical context.
19. AA Battery in Technology and the Internet
AA batteries remain important in technology even though many modern devices now use built-in lithium-ion batteries.
They are especially useful when manufacturers want:
- Easy replacement
- Low manufacturing complexity
- Widely available replacement power
- Long shelf life
- User-replaceable power
- Standardized physical dimensions
Internet and digital technology
AA batteries are associated with many internet-connected or electronic products, including:
- Wireless keyboards
- Wireless mice
- Remote controls
- Smart-home accessories
- Sensors
- Digital cameras
- Electronic toys
- Portable controllers
Some smart devices still use AA batteries because replacing a standard cell can be easier than opening a device or charging a built-in battery.
20. AA Battery in Science
AA batteries provide a simple example of electrochemistry.
They demonstrate several scientific principles:
Chemical energy
The battery stores energy through chemical reactions.
Oxidation and reduction
Electrochemical reactions involve oxidation at one electrode and reduction at another.
Electron flow
Electrons move through the external circuit when the battery is connected to a load.
Voltage
The chemical system establishes an electrical potential difference.
Current
The circuit determines how much electrical current is drawn from the battery.
Capacity
The total useful charge that a battery can provide depends on its chemistry, construction and operating conditions.
Therefore, an AA battery can be used as a simple educational example of the conversion:
Chemical energy → Electrical energy → Useful work
21. UPSC Explanation
For UPSC Civil Services Examination, an AA battery can be understood through concepts from General Science, Environment, Technology and Everyday Science.
Key UPSC points
1. Electrochemical device:
A battery converts chemical energy into electrical energy.
2. Cell and battery:
A cell is an electrochemical unit. A battery can technically consist of multiple cells, although everyday language commonly calls individual cells batteries.
3. Primary battery:
Disposable AA batteries such as many alkaline and zinc-carbon cells are primary batteries.
4. Secondary battery:
NiMH AA batteries are rechargeable secondary cells.
5. Voltage:
Common alkaline AA cells have a nominal voltage of about 1.5 V, while NiMH cells generally have about 1.2 V.
6. Standardization:
AA refers primarily to physical size. Different chemical systems can use the AA form factor.
7. Environment:
Used batteries should be disposed of through appropriate battery-waste or recycling systems because batteries contain materials that require controlled handling.
UPSC-style question
Question: Which statement about an AA battery is correct?
A. Every AA battery has exactly the same chemical composition.
B. AA refers primarily to a standardized battery size.
C. Every AA battery is rechargeable.
D. Every AA battery has a voltage of 3.7 V.
Answer: B
The letters AA primarily identify the physical size; chemistry, voltage and rechargeability can vary.
22. Symbolism and Cultural Importance
The AA battery has little symbolic meaning in the traditional literary sense, but it has strong cultural importance as an object of everyday technology.
It represents ideas such as:
- Portable energy
- Convenience
- Mobility
- Independence from electrical outlets
- Everyday technology
- Emergency preparedness
- Simple engineering
The familiar shape of an AA battery has become recognizable across many countries.
In popular culture, phrases such as “the batteries are dead” can metaphorically describe a person or device that has run out of energy.
For example:
“I am out of batteries today.”
This can humorously mean:
“I am tired and have no energy.”
Thus, battery vocabulary sometimes enters informal human language.
23. Rhyming Words
Because AA battery is a phrase rather than a single ordinary word, exact rhymes are limited.
Words and phrases that can loosely rhyme with battery include:
| Rhyming or near-rhyming word | Type |
|---|---|
| Battery | Exact target |
| Flattery | Strong rhyme |
| Chattery | Strong/near rhyme |
| Scattery | Near rhyme |
| Matter-y | Slant rhyme |
| Clattery | Near rhyme |
| Tatters | Loose rhyme |
For AA, spoken as “double-A,” possible phrase rhymes include words or expressions ending in the long -ay sound:
- Day
- Way
- Say
- Play
- Stay
- Gray
- May
These are phonetic rhymes rather than synonyms.
24. Common Uses
AA batteries are used in a surprisingly large number of products.
Household devices
- Wall clocks
- Remote controls
- Flashlights
- Radios
- Toys
- Electronic thermometers
- Small fans
- Battery-operated lamps
Personal electronics
- Wireless mouse
- Wireless keyboard
- Some cameras
- Portable audio devices
- Game accessories
Outdoor equipment
- Headlamps
- Flashlights
- GPS accessories
- Camping equipment
Educational equipment
- Science experiment kits
- Electronic learning toys
- Simple robotics projects
25. Advantages of AA Batteries
AA batteries remain popular because they offer several benefits.
Standardized size
A device designed for AA cells can accept compatible AA-size products from many manufacturers.
Easy availability
AA batteries are widely sold in shops and online stores.
Variety
Consumers can choose among:
- Alkaline
- Zinc-carbon
- Lithium primary
- NiMH rechargeable
- Other specialized chemistries
Portability
They are small enough for portable equipment.
Replaceability
Users can quickly replace depleted cells.
Rechargeable options
Rechargeable AA cells reduce dependence on disposable batteries for suitable applications.
26. Limitations
AA batteries also have limitations.
Limited energy
They cannot provide unlimited energy and eventually require replacement or recharging.
Leakage risk
Some disposable batteries can leak, especially if stored for long periods or left inside devices after discharge.
Performance varies
Capacity and discharge performance depend heavily on chemistry.
Environmental concerns
Disposable batteries create waste and require appropriate collection and recycling practices.
Incorrect substitution
A physically compatible cell may have an unsuitable voltage or chemistry.
27. Safety and Proper Use
Good battery practices include:
- Check the device manual before selecting a battery.
- Match the correct battery size and chemistry.
- Insert batteries according to the + and − markings.
- Do not recharge batteries unless they are specifically designed to be rechargeable.
- Use an appropriate charger for rechargeable cells.
- Avoid mixing old and new batteries in the same device.
- Avoid mixing different battery chemistries.
- Remove batteries from devices that will not be used for long periods when appropriate.
- Keep batteries away from extreme heat.
- Recycle or dispose of used batteries through suitable collection systems.
A particularly important rule is:
Never assume that a battery with AA dimensions is electrically safe for every AA-powered device.
Some lithium-ion cells have AA-like dimensions but much higher voltage.
28. AA Battery and Rechargeable Technology
Rechargeable AA batteries are particularly useful for frequently used devices.
Suppose a household uses batteries regularly in:
- Wireless mouse
- Game controller
- Flashlight
- Camera
- Toys
Using rechargeable NiMH cells can reduce the number of disposable cells purchased over time.
However, rechargeable cells require:
- A compatible charger
- Correct charging procedures
- Proper storage
- Monitoring for damage or unusual heating
Rechargeable batteries also have a limited service life. Their capacity gradually decreases after repeated use.
29. Common Terms Associated with AA Batteries
mAh
Milliampere-hour, a common measure of battery charge capacity.
Voltage
Electrical potential difference between the terminals.
Capacity
The amount of electrical charge that can be delivered under specified conditions.
Chemistry
The electrochemical system used inside the cell.
Primary battery
A battery generally designed for one discharge cycle and not normal recharging.
Secondary battery
A rechargeable battery.
Terminal
The electrical connection point of the cell.
Leakage
Escape of electrolyte or internal material from a damaged or degraded battery.
Shelf life
The period for which a stored battery can retain useful performance.
30. AA Battery in Everyday Language
People often use the term “AA battery” without knowing its technical designation.
Examples:
- “Buy four AA batteries.”
- “The remote needs two AA batteries.”
- “These are rechargeable AA batteries.”
- “My camera uses AA batteries.”
- “The batteries in the clock are dead.”
The phrase is therefore an excellent example of a technical term that has become part of ordinary household vocabulary.
31. Frequently Asked Questions
What is an AA battery?
An AA battery is a standardized cylindrical battery size commonly used in portable electronic devices.
Is AA the same as 1.5 V?
No. AA describes the size. Many alkaline AA cells are 1.5 V nominal, but rechargeable NiMH AA cells are generally around 1.2 V.
Is AA rechargeable?
Some AA batteries are rechargeable and others are not. NiMH is a common rechargeable AA chemistry.
What is an LR6 battery?
LR6 is the IEC designation for an alkaline battery in the AA-size format.
What is an R6 battery?
R6 is the IEC designation associated with a zinc-carbon AA-size cell.
Are AA and AAA the same?
No. Both are standardized cylindrical sizes, but AA is larger than AAA.
Can I use a 14500 battery in an AA device?
Not automatically. Although some 14500 cells have dimensions similar to AA cells, many lithium-ion 14500 cells have a much higher voltage than ordinary AA batteries.
How long does an AA battery last?
There is no single answer. Operating time depends on battery chemistry, capacity, device power consumption, temperature and other factors.
Why are rechargeable AA batteries usually 1.2 V?
NiMH chemistry has a nominal cell voltage of about 1.2 V. This is normal for the chemistry and does not mean the cell is defective.
Why are AA batteries cylindrical?
The cylindrical design provides a practical balance of manufacturing simplicity, mechanical strength, internal volume and ease of use.
32. Fun Facts About AA Batteries
- The AA size dates back to 1907. It was introduced by the American Ever Ready Company.
- Formal standardization came later. The size was incorporated into ANSI standard sizes in 1947.
- AA does not mean alkaline. An AA battery can use several different chemistries.
- The IEC uses different codes. For example, alkaline AA is commonly LR6, while zinc-carbon AA is R6.
- AA batteries have many names. “Mignon,” “Penlight,” “UM-3” and “HP7” are among the historical or regional names associated with this size.
- AA is bigger than AAA. The larger size generally permits greater energy storage, although actual capacity depends on chemistry and design.
- A single AA cell is technically a cell. Everyday English commonly calls it a battery.
- The letters AA are about size, not energy capacity.
- Rechargeable AA batteries have become important alternatives to disposable cells.
- A battery can look like an AA and still be electrically unsuitable for an AA device. Physical dimensions alone are not enough to determine compatibility.
33. AA Battery: At a Glance
| Question | Answer |
|---|---|
| What is AA? | A standardized cylindrical battery size |
| Common name | Double-A battery |
| Approx. size | 14.5 × 50.5 mm |
| Common disposable voltage | 1.5 V |
| Common rechargeable voltage | 1.2 V |
| Common alkaline code | LR6 |
| Common zinc-carbon code | R6 |
| Common NiMH code | HR6 |
| Common lithium iron disulfide code | FR6 |
| Common ANSI number | 15 |
| Japanese size name | UM-3 |
| Rechargeable? | Some types are |
| Typical applications | Portable electronic devices |
| Introduced | 1907 |
| ANSI standardization | 1947 |
34. Final Meaning
The AA battery is one of the most important standardized battery formats in everyday technology. Its popularity comes from a combination of compact size, convenient shape, broad availability and compatibility with a large range of portable devices.
The most important point to remember is that AA is primarily a size designation, not a specific chemical technology. An AA battery can be disposable or rechargeable and can use different electrochemical systems.
In simple words:
An AA battery is a small, cylindrical, standardized power source used to operate many portable electronic devices.
Its long history, simple design and worldwide availability have made it a familiar part of modern life. From a basic wall clock to a flashlight, toy, wireless mouse or electronic instrument, the humble AA battery continues to provide a practical bridge between stored chemical energy and useful electrical power.
One-line dictionary definition
AA battery: A standardized cylindrical dry cell, commonly available in disposable and rechargeable forms, used to supply electrical power to portable electronic devices.