Comparison of AA battery chemistries
In this article I will look at the 3 different AA battery chemistries: Alkaline, Lithium and NiMH. Alkaline and Lithium are primary batteries, i.e. not rechargeable, NiMH is rechargeable.
I am not including carbon-zinc batteries, they have worse performance than alkaline and are mostly obsolete.
The standard size of AA batteries is 50.5 mm long (including plus pole) and 14.5 mm in diameter, this was standardized in 1947 by IEC (but the battery was in use long before that).
Naming
The AA battery has been around a long time and during that time many different names has been used, both from manufacturers and from standard organizations.
IEC uses R6 for the AA battery size and then places a letter before, depending on chemistry, the most common are: LR6=Alkaline AA, FR6=Lithium AA, HR6=NiMH AA
ANSI uses 15A for alkaline AA, 15LF for lithium AA and 1.2H2 for NiMH AA.
Some of the other names used for the AA cell size is: penlight, mingon, MN1500, M
Voltage, capacity and other info
Alkaline
These batteries are rated 1.5 volt, their actual capacity is seldom specified, because it varies with load.
Energizer has a datasheet with specifications and their AA has about 2900mAh at 25mA load, but only about 1400mA at 500mA load.
According to Energizer the Alkaline battery will work down to -18°C, but with reduced capacity.
The shelf life can be up to 10 years.
The battery weights about 23 gram.
Alkaline batteries is also known to leak and destroy equipment, even unused cells can leak.
Lithium
These batteries are rated with 1.5 volt and has around 3000mAh.
According to Energizer the battery will work down to -40°C, but with reduced capacity.
The shelf life can be up to 15 years.
Unloaded voltage will be around 1.8 volt.
The battery weights about 15 gram.
The lithium batteries compared here is lithium-iron (Li-FeS2) batteries, there does also exist lithium batteries with 3 volt, they are usual sold in other sizes (CR123, CR2), but can also be found in AA size, but cannot be used instead of ordinary AA batteries.
NiMH
These batteries are rated with 1.2 volt, capacity is marked on the cell and is usual in the 2000mAh to 2700mAh range.
According to Sanyo the battery will work down to 0°C, but with reduced capacity.
The shelf life it not rated for rechargeable, but depending on type they can retain charge from a few weeks to a couple of years.
The battery weights 26 to 30 gram.
Comparison
First curve is at fairly low current. The alkaline battery lasts about 22 hours (2.2Ah at 0.1A), half the time is has higher voltage than the NiMH batteries, the rest of the time lower.
The lithium battery is the only battery that stays close to 1.5 volt and it is also the battery that delivers most energy.
Increasing the current to 1A is very hard on the alkaline battery, the voltage drops below the NiMH after a few minutes and continues down.
Again the lithium battery is the best, with highest voltage and most capacity, the capacity drop from 0.1A to 1A is small.
At 3A the alkaline battery cannot do much. NiMH works fine.
The lithium cell is also having problems, first the voltage drops, then it increase again while the cell heats.
The capacity shows how much current is in the batteries.
With energy it is the product of voltage and current that is summed, a buck or boost can use this energy, i.e. it can use extra voltage for more brightness or runtime.
This table is just the capacity converted to time.
Conclusion
The voltage printed on the cells, does not have much relation to actual voltage when using the cell. Alkaline marked with 1.5 volt has lower voltage than NiMH marked with 1.2 volt at higher loads (Like a flashlight on high). At very low loads alkaline will be better than NiMH.
Lithium has the highest voltage in most cases and can handle high loads.
Battery reviews
AA rechargeable
Eneloop AA HR-3UTGB 1900mAh (White)
Eneloop AA HR-3UWXB 2450mAh (Black)
AA primary
Panasonic Pro Power AA
Energizer Ultimate Lithium AA
A article more about batteries and it will be the last for now. The actual contents of this article is a bit on the light side, but I believe it is nice to have a comparison between the different chemistries.
As usual I like getting feedback, both mistakes and ideas to improve the article.
I plan on adding more review links, when I publish reviews for the different batteries.
Very cool review, thanks.
Do most alkalines have similar capacities when discharged at a very low current(0.1A)?
Yes, alkaline are best at low current. 0.1A is not even a low current for alkaline, you need to get even lower to get maximum capacity.
Excellent comparison HKJ. Thanks for the info!
This may be why Alkalines are recommended over rechargeables in clocks.
Thank you! I have been wondering about this for a while. I guess as long as I can keep gettin the energizers at a huge discount I will keep using them primarily
The proper way is to carry at least 20 fully charged eneloops.
Only when I have packers.
Naw, not even then. The only device I use AA's now is my gps, and a set of batteries in it will last a few weeks with the way I use it. Bringing a charger doesn't even make sense. I'll just bring a pair of lithium AA's and start looking for a new pair after a couple weeks. It costs more than nimh, but saves time and weight. I've been considering getting an [AA phone](http://www.spareone.com/spareone/spareone-emergency-phone) though. Probably not though since it's heavier and way more expensive than my burner phone.
It's not the first time I've been called an ass.
Please test Nice lithium from Fasttech
I do not plan on testing a many primary batteries, they are a lot more work, even when I only test once at each current.
But I have ordered some of the NICE batteries and will probably test them.
i was going to ask for Duracell and Energizer AA battery tests, since they are the most popular name brand Alkaline.
Thanks for the review, HKJ!
Don’t use Duraleaks though! (To be fair, P&G kindly reimbursed me for the damaged clock).
Duracell is a possibility, they have been on sale lately and I got a large pile of "Plus power", but I do not know when (I have a lot of Sibeile batteries to test).
Thanks, i thought you may be able to settle the Duracell - Energizer rivalry by showing which is better, or if there is a difference between them at all
HKJ, awesome review and I can’t wait to read through some additional ones. This answered a lot of questions I had as to which cells are actually the best for different purposes, thank you!
Not at the current time, also note that Duracell has multiple series of batteries, the "Plus power" is not their best battery.
I will not really call this a review (Reviews will follow later), it is more of a comparison.
Very true, in the old days there was just the regular Duracell and Energizer
One problem. If you’re out hiking and encounter a small town, you may very well find that Energizer Ultimate Lithiums are not available. Whenever I’ve looked in a small town gas station or a small store in the middle of the Sierra (Things are probably the same elsewhere), about all you can get are basic alkaline AAA, AA, C and D batteries. Some stores even skip the AAA and C cells, selling only AA and D cells. In other words, I’m SURE you’ve probably been forced to use alkaleaks.
Speaking of taking time to charge NiMH batteries in small towns, ever consider a solar charger? Not sure where you hike. But at least in many of the western mountains, the powerful sunlight actually does a GREAT job charging batteries.
Thanks for the very informative last couple of battery reviews. It was interesting to see the lithium battery drop from near on 1.75 volts to 1.53 volts with only .1 amp load but hold the voltage very well for the life of the cell. I bought my father some of these cells for his digital camera after using NiMH and he hasn’t gone back. They seem to last 10 times longer than anything else even though they are not cheap. Cheers.