You must have used or heard of 18650 batteries and AA batteries before. Both of these types of batteries are very common in everyday life, and are even indispensable. So, what are their similarities and differences? Let’s take a look at this comparison guide of 18650 batteries and AA batteries together!

What is an 18650 Battery?

18650 batteries originated in 1994 and are the earliest form of lithium-ion batteries. The term “18650” refers to the battery’s physical dimensions. Its diameter is 18mm, and its length is 65mm, hence the name “18650,” with the ‘0’ indicating its cylindrical shape.

As a lithium-ion battery, the 18650 has the following strengths and weaknesses:

  • Advantage

1. Common standard

2. Large capacity

3. Long lifespan

4. Rechargeable

5. No memory effect

6. Low internal resistance

7. Can be connected in series or parallel to form a battery pack

8. Wide range of applications

  • Disadvantage

  1. Fixed volume
  2. BMS must be used to protect the line
  3. Strict production
18650 Battery

18650 Battery

What is an AA Battery?

AA batteries are cylindrical dry cell batteries, also known as size 5 batteries. Similarly, “AA” refers to the physical size of the battery, typically having a diameter of 14.5mm and a height of 50.5mm. AA batteries are widely used in various portable electronic devices, such as remote controls, alarm clocks, flashlights, and toys in your home. Here are the advantages and disadvantages of AA batteries:

  • Advantage

  1. Good versatility

AA batteries are widely used due to their common specifications. Many household electronic devices, such as remote controls and alarm clocks, can use them. They are incredibly convenient.

  1. Easy availability

AA batteries are very common; even in emergencies, you can easily find them at nearby convenience stores.

  1. Low cost

AA batteries are also available in rechargeable variants, which effectively reduce overall usage costs.

  1. Wide applicability

AA batteries have a wide range of applications and can be used in various small appliances, digital products, and low to medium power electronic devices.

  • Disadvantage

1.Disposable AA batteries, when discarded without proper disposal, can easily pollute the environment.

2.If your devices require frequent battery replacement, it can be inconvenient for you, and the cost of purchasing batteries can add up significantly.

3.For devices with high power consumption, the battery life of AA batteries may not be sufficient.

The Difference Between 18650 Batteries VS AA Batteries?

  • Size (Dimension)

18650 Battery: Cylindrical battery with a diameter of 18mm and a height of 65mm.

AA Battery: Cylindrical battery with a diameter of 14.5mm and a height of 50.5mm.

  • Chemistry

18650 Battery: Common types include lithium-ion batteries, lithium iron phosphate batteries, and nickel-metal hydride batteries. The type most commonly used now is the 18650 lithium-ion battery.

AA Battery: Common types include nickel-metal hydride rechargeable batteries, nickel-cadmium rechargeable batteries, alkaline zinc-manganese batteries (referred to as “alkaline batteries”), and regular acidic zinc-manganese batteries (referred to as “regular batteries”).

  • Rechargeability

18650 Batteries: These are all rechargeable batteries. You can charge them multiple times and reuse them.

AA Batteries: There are both non-rechargeable batteries (zinc-manganese batteries) that can only be used once, and rechargeable batteries (nickel-metal hydride batteries, nickel-cadmium batteries) that can be reused.

  • Voltage

18650 battery: The nominal voltage for a single cell is generally 3.6V or 3.7V, the charging voltage is generally 4.2V, the minimum discharge termination voltage is generally 2.75V, and the maximum charging termination voltage is 4.20V.

AA battery: The voltage is generally 1.2V and 1.5V. Specifically,

the voltage of a single ordinary zinc-manganese acid battery is 1.5V;

the voltage of a single alkaline battery is 1.5V,

the voltage of a single rechargeable nickel-cadmium/nickel-metal hydride battery is 1.1V or 1.2V.

  • Current

18650 Battery: The current of this type of battery is usually above 2Ah and is commonly used in high-power devices. The higher the power, the greater the provided current. Some 18650 lithium-ion batteries can even provide a current higher than 30Ah.

AA Battery: The current of AA batteries is generally between 1800-2200mAh, suitable for moderate-power devices.

  • Capacity

18650 Battery: The capacity is usually above 1000mAh, with a standard capacity of 2200mAh-3200mAh. Currently, the highest capacity is LG’s 18650 battery, with a capacity of 3600mAh.

AA Battery: Generally around 1000mAh.

Alkaline Battery: Capacity is between 1800-2700mAh.

Zinc Manganese Battery (NiZn): 1500 – 1800 mAh

Rechargeable Nickel Cadmium Battery (NiCd): 600 – 1000 mAh

Rechargeable Nickel Metal Hydride Battery (NiMH): 700 – 2800 mAh

  • Energy Density

18650 Battery: High energy density, typically 150-220wh/kg, is 1.5-2 times that of nickel-metal hydride batteries of the same weight.

AA battery: Energy density is around 297wh/kg, slightly lower than 18650 batteries.

  • Weight

18650 Battery: The standard weight of a 18650 lithium-ion battery is between 45g and 50g.

AA Battery: The weight of an AA battery generally ranges from 23g to 31g.

  • Performance

18650 battery: Stores more capacity, longer battery life.

AA battery: Smaller capacity, shorter battery life.

  • BMS

18650 Battery: BMS is required and very important for rechargeable 18650 batteries.

AA Battery: BMS is usually not needed.

  • Lifespan

18650 batteries: 18650 lithium-ion and lithium iron phosphate batteries can endure several thousand charge-discharge cycles.

AA batteries: Non-rechargeable AA batteries are disposable and can only be used once, while the rechargeable AA batteries can support 500-1500 charge-discharge cycles.

  • Application

18650 battery: Commonly used in rechargeable devices with high battery requirements, such as laptop batteries, power tools, etc.

AA battery: You should use it in devices with lower power requirements such as toys, remote controls, digital cameras, etc.

  • Cost

18650 battery: Higher cost, mostly used in rechargeable devices.

AA battery: Lower cost, mostly used in household devices.

Can We Use AA Batteries Instead of 18650 Batteries?

From the above content, it can be seen that there are certain differences between the two. In terms of size and voltage, you cannot replace an 18650 battery with an AA battery. 

If you need batteries with larger capacity and density, you can choose 18650 lithium batteries; if you need more cost-effective batteries, you can consider AA batteries. 

Which is More Popular 18650 Battery vs AA Battery?

In general, AA batteries came into existence earlier than 18650 batteries. However, in terms of performance,  18650 batteries outperform AA batteries. 18650 batteries are commonly used in higher power devices, while AA batteries are more commonly used in small household appliances, and electric toys, and more.

Conclusion

The above provides a comparison of 18650 batteries and AA batteries; I hope you find it helpful.

FAQ

Can I Charge 18650 Battery With AA Charger?

It would be best if you used a specific charger to charge the 18650 battery and, at the same time, avoided overcharging and over-discharging to ensure battery safety.

Are 18650 Batteries the Same as AA?

They are two different types of batteries. They differ in size, chemical composition, voltage, current, capacity, and overall performance. 18650 batteries are commonly used in higher-powered devices, while AA batteries find more application in small household appliances and toys.