Open main menu

Wikipedia β

AA cells

The AA battery—also called a double A or Mignon (French for "dainty") battery—is a standard size single cell cylindrical dry battery. The IEC 60086 system calls it size R6, and ANSIC18 calls it size 15.[1] Historically, it is known as SP7 (Standard Power 7) or HP7 (High Power 7) in official documentation the United Kingdom, though it is colloquially known as a "double A battery".

AA batteries are common in portable electronic devices. An AA battery is composed of a single electrochemical cell that may be either a primary battery (disposable) or a rechargeable battery. The exact terminal voltage and capacity of an AA size battery depend on cell chemistry; however, devices designed for AA will usually only take 1.5 V unless specified by the manufacturer.

Introduced in 1907,[2] the AA battery size was standardized by the American National Standards Institute (ANSI) in 1947, but it had been in use in flashlights and electrical novelties before formal standardization. ANSI and IEC Battery nomenclature gives several designations for cells in this size, depending on cell features and chemistry.

Contents

DimensionsEdit

 
D, C, AA, AAA, AAAA cells, and a 9-volt battery

An AA cell measures 49.2–50.5 mm (1.94–1.99 in) in length, including the button terminal—and 13.5–14.5 mm (0.53–0.57 in) in diameter. The positive terminal button should be a minimum 1 mm high and a maximum 5.5 mm in diameter, the flat negative terminal should be a minimum diameter of 7 mm.[1] 14500 Lithium Batteries are longer if they feature a protection circuit up to 53 mm.

Alkaline AA cells have a weight of roughly 23 g (0.81 oz),[3] lithium AA cells around 15 g (0.53 oz),[4] and rechargeable Ni-MH cells around 31 g (1.1 oz).[5]

Chemistry and capacityEdit

Primary cellsEdit

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. Zinc–carbon batteries are usually marketed as "general purpose" batteries. Zinc-chloride batteries store around 1000 to 1500 mAh are often sold as "heavy duty" or "super heavy duty". Alkaline batteries from 1700 mAh to 3000 mAh cost more than zinc-chloride batteries, but hold additional charge.

Non-rechargeable lithium iron disulfide batteries are manufactured for devices that use a lot of power, such as digital cameras, where their high cost is offset by longer running time between battery changes and more constant voltage during discharge. Another advantage of lithium disulfide batteries compared to alkaline batteries is that they don't tend to leak. This is particularly important in expensive equipment, where a leaking alkaline battery can cause damage to the point of requiring replacement of the equipment. Lithium iron disulfide batteries are intended for use in equipment compatible with alkaline zinc batteries. 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. A fresh alkaline zinc battery can have an open-circuit voltage of 1.6 volts, but an iron-disulfide battery with an open-circuit voltage below 1.7 volts is entirely discharged.[6]

Rechargeable cellsEdit

 
A solar-powered charger for rechargeable AA batteries
 
Panasonic Eneloop 1.2 volt NiMH rechargeable batteries in AA and AAA

Rechargeable batteries in the AA size are available in multiple chemistries: nickel–cadmium (NiCd) with a capacity of roughly 600–1000 mAh,[7] nickel–metal hydride (NiMH) in various capacities of 1300–3500 mAh[citation needed] and lithium-ion. Lithium ion chemistry has a nominal voltage of 3.6-3.7 volts, and are referred to as 14500 Li-ion batteries rather than AA.

The most recent major development in rechargeable AA's are the 1.5 volt AA compliant Li-ion compatibles available in sizes up to 3000mWh/2000mAh since their original release in 2014, as was originally developed, patented, and sold by the Chinese company Kentli. These use normal 14500 3.7 volt Li-ion cells that are combined with an internal voltage regulator (specifically a buck converter) to downstep the output voltage (and only the output) from the normal 3.7 V to an extremely consistent (when compared to traditional alkaline disposables or older Ni-Ca and even NiMH rechargeables) 1.5 V AA standard current. This makes them far and away the superior choice for use-cases in which voltage consistentcy is important (such as certain electronic firearm sights), but without having to compromise on voltage output as with NiMH. And because only the output is converted, they still charge at the 14500's full 3.7 V or higher input (up to a current max available ratio of 5 V in to 1.5 V out, or a 3.5 times faster maximum possible charge to discharge rate), making this particular solution doubly advantageous.

And thus, unlike standard 14500 Li-ion batteries with their dangerously high native 3.7 V output (which can potentially destroy devices designed for the 1.5 V AA-standard), these are able to provide near perfect drop in compatibility in almost anywhere standard AA's are used; while still retaining all of the 14500's other inherent advantages such as capacity, cycle endurance, and it's more than 3.7 V input voltage/charging speed. With the only major exceptions to this being those devices that absolutely require the lower 1.2 volt output found on certain AA's, and most specifically those that are NiMH based (with most devices designed for 1.2 V working with 1.5 V just fine, albeit running slightly brighter in a flashlight or faster in an electric razor for example, and so on. This is of course due to the consistently slightly higher voltage output). [8]

Nickel-zinc cell (NiZn) AAs are also available, but not widely used.

ComparisonEdit

Type Zinc–Carbon Alkaline RAM Li-FeS2 Li-ion NiCd NiMH NiZn
IEC name R6 LR6 LR6 FR6 ? KR6 HR6 ZR6
ANSI/NEDA name 15D 15A 15A 15LF 14500 1.2K2 1.2H2 ?
Capacity under 50 mA constant drain 400–1700 mAh 1800–2600 mAh 1800–2600 mAh 2700–3400 mAh 600-840 (600-2000 at 1.5 V) mAh 600–1000 mAh 600–2850 mAh 1500–1800 mAh
Nominal voltage 1.5 V 1.5 V 1.5 V 1.5 V 3.6-3.7 V OR 1.5 V 1.2 V 1.2 V 1.6-1.65 V
Max. energy at nominal voltage and 50 mA drain 2.55 Wh 3.90 Wh 3.90 Wh 5.10 Wh 2.88-2.96 Wh 1.20 Wh 3.42 Wh 2.97 Wh
Rechargeable No Some Yes No[9] Yes Yes Yes Yes

UseEdit

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). In Switzerland, AA batteries totaled 55% in both primary and secondary (rechargeable) battery sales.[10][11][12]

See alsoEdit

ReferencesEdit

  1. ^ a b Classic (LR6) datasheet from energizer.com
  2. ^ "About Eveready®". Eveready. Retrieved August 8, 2017. 
  3. ^ "Energizer Alkaline AA Battery Specification" (PDF). Product Datasheet. Energizer. Retrieved October 21, 2015. 
  4. ^ "Energizer Lithium AA Battery Specification" (PDF). Energizer. Retrieved October 21, 2015. 
  5. ^ "Energizer NiMH AA Battery Specification" (PDF). Energizer. Retrieved October 21, 2015. 
  6. ^ Lithium Iron Disulfide Handbook and Application Manual, Version LI4.04, Energizer Battery Manufacturing Inc.
  7. ^ Bergveld, H; Kruijt, W; Notten, P (February 1999). "Electronic-network modelling of rechargeable NiCd cells and its application to the design of battery management systems". Journal of Power Sources. 72 (2): 143–158. doi:10.1016/S0378-7753(98)00188-8. 
  8. ^ "Teardown of Kentli PH5 1.5 V Li-Ion AA battery". Jason Gin. Retrieved April 24, 2018. 
  9. ^ Lithium Iron Disulfide, Handbook and Application Manual
  10. ^ Absatzzahlen 2008 INOBAT 2008 statistics.
  11. ^ Life Cycle Impacts of Alkaline Batteries with a Focus on End-of-Life – EPBA-EU
  12. ^ Monthly battery sales statistics – MoETI – March 2011

External linksEdit