AA battery

[citation needed] Due to their popularity in small flashlights, they are often called "penlight batteries".

[10] Primary (non-rechargeable) zinc–carbon (dry cell) AA batteries have around 400–900 milliampere hours capacity, with measured capacity highly dependent on test conditions, duty cycle, and cut-off voltage.

Non-rechargeable lithium iron disulfide batteries are manufactured for devices that draw more current, such as digital cameras, where their high cost is offset by longer running time between battery changes and more constant voltage during discharge.

Lithium-iron disulfide batteries can have an open-circuit voltage as high as 1.8 volts, but the closed-circuit voltage decreases, making this chemistry compatible with equipment intended for zinc-based batteries.

NiMH and lithium-ion AA/14500 cells can supply most of their capacity even when under a high current drain (0.5A and higher), unlike alkaline and zinc-chloride ("Heavy Duty"/"Super Heavy Duty") cells which drop to a small fraction of their low current capacity before even reaching 1 C.[15][16][17][18] A Li-ion 1.5V AA-size battery, sold by the Chinese company Kentli as "Kentli PH5" since 2014 and with similar batteries later available from other suppliers is a AA-sized battery housing containing a rechargeable 3.7 V Li-ion cell with an internal buck converter at the positive terminal to reduce the output voltage to 1.5 V.[19] The Kentli batteries expose the normal 3.7 V Li-ion electrode in a ring around the AA electrode to allow charging by a special charger.

[20] Its capacity at 250 mA drain is 1,700 mAh at 1.5 V, less than other chemistries, limited by the low efficiency of the step-down converter.

[21] Some later Li-ion AA batteries advertise their capacity in milliwatt-hours (mWh) instead of the usual milliampere-hours (mAh), so a customer's attention is drawn to the figure, typically a claimed 3,000 or more, which is in reality 2,000 mAh.

In 2011, AA cells accounted for approximately 60% of alkaline battery sales in the United States.

In Japan, 58% of alkaline batteries sold were AA, known in that country as tansan (単三).

Researchers at Princeton University produced a video showing bounce height with each 10% of discharge.