3xAA Batteries vs 32650 Battery
AA and 32650 batteries differ in size and very often in chemistry, having different discharge voltages, capacities, drain currents, shelf lives, and similar.
However, when three AA batteries are placed next to each other, their physical dimensions are similar to a single 32650 battery, making people wonder if three AA batteries may be used instead of a single 32650 battery.
Published: October 27, 2021.
AA and 32650 Batteries Features and Specifications
AA batteries are very popular cylindrical batteries featuring physical dimensions of (DxH) 14.5 x 50.5 mm and a typical nominal voltage of 1.5V.
We say "typical nominal" voltage since zinc-carbon AA batteries were the first chemistry type of AA batteries introduced on the market.
Today, AA batteries may be found in many chemistries, each having different storage and discharge characteristics, including Zinc-Carbon, Alkaline, Nickel Oxy-Hydroxide, Lithium Iron Disulfide, Lithium Thionyl Chloride, Lithium Manganese Dioxide, Nickel Cadmium, Nickel Metal Hydride, Nickel Zinc, etc.
The following comparison chart lists some of the most popular AA battery chemistries with their most important features and specifications:
|Chemistry||Common Name||Rechargeable||Typical Capacity (mAh)||Voltage (V)
|Zinc Carbon||R6, 15D||No||600 - 1600||1.5|
|Alkaline||LR6, 15A||No (Mostly No)||1800 - 2700||1.5|
|Li-FeS2||FR6, 15LF||No||2700 - 3300||1.5 (1.8 max)|
|Li-ion||14500||Yes||600 - 2000+||3.6 - 3.7|
|NiCd||KR6, 1.2K2||Yes||600 - 1000||1.2|
|NiMH||HR6, 1.2H2||Yes||700 - 2800||1.2|
|NiOOH||-||No||2200 - 2700||1.5 (1.7 max)|
|NiZn||ZR6||Yes||1500 - 1800||1.6 - 1.65|
32650 batteries are large and powerful lithium rechargeable cylindrical batteries, featuring physical dimensions of (DxL) 32 x 67.7 mm, a nominal capacity of 5-9 Ah, and a nominal voltage of 3.2-3.7 volts, depending on the exact battery chemistry.
32650 batteries may be offered with different battery terminal types (button top, flat top, soldering tabs, screw terminals, etc.) and can have Battery Management System (BMS - highly recommended) built-in that monitors the battery condition and if required, protects the battery from unwanted charge/discharge conditions.
When three AA batteries are placed next to each other, they may fit the battery compartment intended for a single 32650 battery.
That is why some companies offer a 3xAA battery adapter/holder which allows three AA batteries to fit the battery compartment intended for a single 32650 battery.
However, before replacing a single 32650 battery with three AA batteries, be sure that the device that is using that single 32650 battery may be powered by three AA batteries connected in series.
Also, be sure that the discharge characteristics of the new 3xAA batteries suit your short- and long-time requirements.
For example, Lithium Iron Phosphate (LiFePO4) and Lithium-Ion 32650 batteries may have typical values of:
- LiFePO4 32650 battery (IFR32650): 3.2V, 6000 mAh,
- Lithium-Ion 32650 battery (IMR32650, INR32650): 3.7V, 8000 mAh.
If these batteries are compared with 3xAA batteries connected in series, one gets:
- Alkaline 3xAA: 4.5V, 1800 - 2700 mAh,
- Li-FeS2 3xAA: 4.5-4.8V, 2700 - 3300 mAh,
- NiOOH 3xAA: 4.5-5.1V, 2200 - 2700 mAh,
- NiCd 3xAA: 3.6V, 600 - 1000 mAh,
- NiMH 3xAA: 3.6V, 700 - 2800 mAh,
- NiZn 3xAA: 4.8-5.0V, 1500 - 1800 mAh,
- Li-SOCl2 3xAA: 10.8-11.1V, 2400-2700 mAh,
- Li-Ion 3xAA: 10.8-11.1V, 600 - 2000+ mAh, etc.
In terms of voltage, the closes three AA connected in series are NiCd and NiMH batteries with a nominal voltage of 3.6V. However, the actual capacity is much lower than the capacity of the single 32650 battery.
Other AA battery chemistries feature nominal voltage of three AA batteries connected in series in the 4.5-11.1 volts, which is a higher voltage of the single 32650 battery.
If You plan on replacing a single 32650 battery with three AA batteries having 1.5+ volts (single battery), check the device's documentation and verify if it allows such high voltage - if not, such higher voltage may easily damage or even destroy the device.
Why to replace a single 32650 battery with three AA batteries?
If your device supports the use of both 32650 battery and 3xAA batteries, having 3xAA batteries make sense for standby and similar devices - for example, LiFeS2 AA batteries may have a shelf life of up to 20 or even more years, while 32650 battery must be recharged every 3-6 months to keep it properly charged.
32650 flashlights are high-output flashlights, still rather compact to be used as Every Day Carry (EDC) flashlights that may be used only occasionally, after years of not being in use - for such devices somewhat lower energy density of 3xAA batteries should not be a problem.
But, for applications that rely on the energy stored in 32650 batteries, replacing them with AA batteries doesn't make much sense, unless high-capacity Lithium-Ion AA batteries (14500 batteries) are used. But, even then 32650 batteries have an upper hand ...