By Erik Watkins

18650 Battery Vs AA – A Detailed Comparison

Last updated: May 16, 2023
18650 Vs AA Battery

Similar to the 18650 battery, you can also find AA batteries in the battery section in the store. However, are 18650 batteries the same as AA?

This article provides a full comparison between 18650 battery vs AA, so that you will not need to confuse between the two! Keep scrolling down for further information on these types of batteries to protect your power devices!

Difference Between 18650 Battery Vs AA

18650 Battery

18650 battery

The battery size of 18650 is about 18.6 x 65.2 mm. It is slightly larger than an AA battery, and its voltage is also higher. 3.7 V is the output voltage of this battery, with a capacity of 1800 – 5000 mAh.

It is a rechargeable lithium-ion battery, also known as a “protected 18650” battery. The name comes from the 18650 battery, usually with BMS, which stands for Small Battery Management System. This part is responsible for preventing the battery from unwanted damage.

The BMS is due to the sensitive nature of the battery’s charging and discharging. In addition, there are also differences between the 18650 batteries in the physical shape of the anodes. Some batteries have a flat tip, while others have a tip-top shape.

As long as it’s not too cold or too warm, just put this type of power bank in the charger, and it will recharge without being affected by the battery’s memory. That is one of the characteristics brought about by lithium chemistries.

AA Battery

AA Battery

AA batteries are smaller in size, only about 14.5 x 50.5 mm. This common type of battery can be made from various chemistries such as Zinc Carbon, Alkaline, NiCd, NiOOn, etc. AA batteries made from different chemical compositions will have different properties.

While there are now rechargeable AA batteries available such as AAs made from Li-ion, NiMH, or NiCd, the typical AA batteries people talk about are often non-rechargeable.

Moreover, when talking about AA batteries, we also often recall batteries with a voltage version of 1.5 V with mAh of 1800-2700 as the standard typical capacity.

18650 Rechargeable Batteries Vs. AA

The first noticeable difference between these two batteries is the difference in size. That leads to the amount of energy stored in them, the current capability, being different because the larger size can contain more energy-carrying matter. 

In other words, the lengths of the power supply may be longer, leading to the longer operating time of devices such as digital cameras, wireless mouse, remote controllers, wall clocks, etc.

Predictably, the 18650 battery will have more energy reserves. For example, a 3.7 V 18650 battery with 2000 mAh has the amount of power of 7.4 Wh; 4000 mAh capacity is up to 14.8 Wh.

Meanwhile, typical AA batteries can be considered. AA 1.5 V alkaline batteries, 1200 mAh capacity, the energy reserve is only 1.8 Wh; NiOOH 2500 mAh battery is 3.75 Wh. Even the 3.7 V lithium-ion battery only goes up to 5.55 Wh.

Currently, some devices allow AA batteries to replace the 18650 battery with a battery adapter. But both energy input and power output will be reduced, and the time between battery changes will be shortened.

Frequently Asked Questions 

What Can Replace A 18650 Battery? 

AA batteries are not a good alternative, so what is a good 18650 battery equivalent? You can choose from batteries such as 21700, 26650, or 20700.

The 21700 battery is the one we most recommend. It is seen as an upgrade over the 18650. The 21700 battery will also provide more power and longer endurance in the power supply.

In addition, the 26650 battery is also a good choice for replacement. It is often confused with the 18650 battery, but it has more capacity. So, if you can’t get a 21700 battery, opt for this battery instead.

Can AA Battery Chargers Be Used For 18650 Batteries?

The answer is no. Because the voltage difference between these two batteries is very different, you cannot use the AA battery charger for the 18650 battery.

The voltage of a standard AA battery is 1.5 V, while that of a 18650 battery is 3.7 V. So, the charger won’t be able to charge the 18650 because 2V is the cut-off voltage.


Now you know the difference between a 18650 battery vs AA and other relevant knowledge. The 18650 battery stores more energy, and you can find a solution for it without shortening the life of your portable power devices!

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Automotive Mechanic at PowerAll

With 7 years experience in management positions leading automotive mechanics at PowerAll, Erik Watkins wishes to share useful knowledge and information about automotive mechanical equipment.


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