All batteries have their own benefits and flaws. Since batteries are
basically a commodity they are most economically purchased according to
price, although the cheapest available (normally
a zinc-carbon) will give very bad value for money since they have very low
capacities even when used in very low current situations, which also means there'll be the hassle of changing them often. I recommend inexpensive alkalines instead.
The Digi1 from GP is perhaps my favourite single-use AA cell - it's inexpensive
and has lots of power. However its higher than normal voltage means it's
not for all devices. It might blow some torch bulbs, for example. They're
also hard to find.
If looking for a premium product Duracell and Energizer are normally
top of the brand list, with Energizer's lithium battery range the longest
lasting single-use batteries in their particular sizes over a wide range
of current drains. They're very expensive though.
Non-rechargeable battery type
Pros
Cons
Zinc-carbon
(dry cell)
400-900 mAh
Inexpensive.
Poor shelf life, temperature dependant (approx 15% loss per
year - ideally store in fridge or freezer; over 45°C completely
discharged in one year).
Poor storage density, especially in high current situations
(strong Peukert Effect).
Not suited for medium or high current uses.
Can leak when old (and sometimes not very old).
Zinc-carbon,
"heavy duty", "super
heavy duty"
(zinc chloride)
1000-1500 mAh
Inexpensive, readily available.
Lasts longer than ordinary zinc-carbon batteries in higher current
situations, and slightly better in cold and hot situations.
Poor shelf life (ideally store in fridge or freezer).
Poor storage density, especially in high current situations
(strong Peukert Effect).
Not suited for medium-high or high current uses.
Can leak when old.
Alkaline
1700-2850 mAh
Long shelf life (approx. 5% loss in first year, 2% in subsequent
years).
Readily available and thus quite inexpensive these days (depending
on brand).
Excellent value for money for low to medium drain (<500mA).
Depending on the application, alkaline cells can last for four
to nine times the life of more traditional zinc-carbon cells.
The advantage is greatest under heavy loads that are infrequently
used - that is, something that draws heavy current for half an
hour once a day rather than for a few minutes of each hour.
Capacity is reduced at high current draws (Peukert Effect).
Can leak potassium hydroxide when very old.
Alkaline, modified
(eg, Duracell Ultra, Energizer e2)
Up to 2900 mAh
Long shelf life.
Higher short-circuit current output than standard alkalines
because of lower internal resistance.
Designed to be more suited to high current situations than standard
alkaline (lower Peukert Effect than standard alkalines).
Capacity is still reduced at high current draws (Peukert Effect
still present).
At end-of-life its voltage drops more suddenly than standard
alkalines.
Nickel Zinc
(NiZn)
eg, GP Digi1
Good performance in high current applications, comparable to
modified alkaline (eg, Duracell Ultra, Energizer e2).
Higher average voltage (and therefore more watts) over useable
life than alkaline batteries.
Excellent value for money in high current situations (compared
with other non-rechargeable batteries).
Hard to find – in NZ they were only sold as AA cells at Dick Smith Electronics way back when they sold real electronics.
Prices around the world vary by a factor of 10.
Similarly variable voltage to alkaline (starts @ 1.7V, ends
@ 1.0V; alkaline start @ 1.6V, finish at 0.9V if you're lucky).
The higher voltage may not be good for some devices.
Nickel Oxyhydroxide
(NiOOH)
Good performance in high current applications, comparable to
modified alkaline (eg, Duracell Ultra, Energizer e2).
Higher average voltage (and therefore more watts) over useable
life than alkaline batteries.
Good value for money in high current situations (compared with
other non-rechargeable batteries).
Still uncommon.
Similarly variable voltage to alkaline (starts @ 1.7V, ends
@ 1.0V; alkaline start @ 1.6V, finish at 0.9V if you're lucky).
The higher voltage may not be good for some devices.
Lithium iron-disulfide
(eg, lithium AA)
3000 mAh
200 Wh/kg
Very long shelf life.
High current output.
Begins to be cost effective in high current situations (>1A)
because of lower Peukert Effect than other chemistries.
Light weight.
Good performance in freezing conditions.
Very expensive.
Not cost effective in low and medium current output situations.
Alkaline button
Small size/weight.
Cheaper than alternatives (such as silver oxide).
Low current output (which may be a desirable feature if, for
example, running LEDs).
Silver oxide button
Small size/weight.
Good storage density.
Extremely level output voltage curve during life.
Low current output (which may be a desirable feature if, for
example, running LEDs).
Lithium button
Small size/weight.
Good storage density.
Extremely level output voltage curve during life.
Higher voltage than other button cells.
Low current output (which may be a desirable feature if, for
example, running LEDs).
Zinc air button
220-300 Wh/kg
900 Wh/L
High voltage, 1.65V per cell (no load).
Very level discharge curve.
Extremly long shelf life (approx. 2% loss per year).
Very high storage density because it doesn't carry its own oxidiser
(it uses oxygen from the air).
Best used in often-used or always-on situations.
Short life (a few months) once packet is opened.
Low current output due to high internal resistance.
Miscellaneous notes on single-use batteries
Interestingly Energizer no longer makes their e2 batteries in AAAA, C
or D sizes but they do now make lithium AAA cells and 9V batteries. Some
9V batteries are made of six AAAA cells in series (AAAA cells are very
thin cylindrical cells), while others are a column of rectangular cells.
There don't seem to be many manufacturers of single-use NiZn batteries.
It makes me wonder if GP's Digi1 are a by-product of their attempts to
manufacture rechargeable NiZn batteries, since they make good rechargeable
NiMH cells. Digi1 are good batteries in their own right, though, and Consumer magazine (Dec 2006) rated them second only to rechargeables for cost-effectiveness for digital camera use, thanks to the very high
cost of similarly performing cells from other manufacturers. I buy them
myself - one set of four lasted for two caving trips (although the light
wasn't the best for the second trip).
Silver oxide button cells are interchangeable with their lithium button
cell counterparts, eg the silver oxide SR44 is interchangeable withthe
lithium LR44. Also, a W after the type, eg SR44W, indicates a high drain
cell. SW or no suffix indicates a low drain cell.
Notes on NiOOH
Panasonic's Oxyride battery (available in AA and
AAA sizes) appears similar to NiZn technology, if not the same thing.
They replace the managnese oxide electrode found in a normal alkaline
cell with nickel oxyhydroxide (NiOOH). Presumeably zinc remains
in the other electrode - they have a similar initial voltage to
GP's NiZn batteries. Panasonic claims the Oxyride technology is
the biggest advance in single-use battery technology in 40 years.
Panasonic got Oxyride on the market in April 2004 and in their
first year had captured 10% of the market share - an indication
of how good they are for a new product in a very competitive market.
Panasonic demonstrated two AA Oxyride batteries powering
an 18kg car with 47kg driver for 1.23km (at a slow walking speed)
and in a later demonstration used 160 Oxyride batteries to power
a light-weight aeroplane. It carried a 53kg pilot for a 391 metre
flight lasting just under one minute.
The next generation of Oxyride batteries will supposedly have even
better performance in digital cameras but it's said they won't do
as well in always-on situations.
Kodak's Oxy-Alkaline AA cells apparently also use NiOOH chemistry,
since in a recent Consumer magazine test they performed similarly
to the Panasonic Oxyride cells... but cost 50% more.
Duracell have also now released their version of the NiOOH cell, which they
call PowerPix, "a battery that is designed using NiOx™
Technology, based on nickel oxyhydroxide chemistry".