# How many mah do batteries have **URL:** \ **Category:** Factual Questions\ **Created:** [February 22, 2015, 12:39am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303 "2015-02-22T00:39:21Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [February 22, 2015, 12:39am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/1 "2015-02-22T00:39:21Z")
By batteries, I mean the common disposable alkaline ones. AAA AA C D 9V lantern battery etc. but mostly the first 5 in that list. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [February 22, 2015, 1:23am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/2 "2015-02-22T01:23:00Z")
> [@Wesley\_Clark](#): > > By batteries, I mean the common disposable alkaline ones. > > AAA > AA > C > D > 9V > lantern battery > > etc. but mostly the first 5 in that list. that really is an “it depends” kind of question. _In general_, the capacities of those size alkaline cells are around: AAA: 700-900 mAh AA: 2200-2500 mAh C: 5000-6000 mAh D: 9000-12000 mAh 9V: 300-400 mAh the “it depends” part is because with typical alkaline chemistry, the actual capacity depends on how fast you try to draw current from them. If you’re drawing a bare trickle, you can expect to get close to the theoretical capacity. If you’re drawing higher currents, the actual available capacity goes down. This is where rechargeables like NiCd and NiMH excel; they have much lower internal resistance so their capacity is not so different between low and high current draws. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [February 22, 2015, 1:33am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/3 "2015-02-22T01:33:32Z")
mah? meh? hmm? Oh! Milliamp-hours! Now I get it! ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [February 22, 2015, 3:53am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/4 "2015-02-22T03:53:13Z")
I know you asked about mAh, but _very_ generally speaking, the “bigger” the battery the more (potential) energy it contains. Some may argue _mass_ is most relevant, while others argue that _volume_ is most relevant. ---
**Author:** ![boffking](https://avatars.discourse-cdn.com/v4/letter/b/858c86/32.png) [@boffking](https://boards.straightdope.com/u/boffking)\ **Post date:** [February 22, 2015, 4:29am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/5 "2015-02-22T04:29:49Z")
> [@Crafter\_Man](#): > > I know you asked about mAh, but _very_ generally speaking, the “bigger” the battery the more (potential) energy it contains. Some may argue _mass_ is most relevant, while others argue that _volume_ is most relevant. I would argue that the chemistry of the battery is more relevant than the size. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 22, 2015, 4:32am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/6 "2015-02-22T04:32:52Z")
I recall a simple LED flasher circuit that was estimated to run a year on a D cell. That’s the best example I know of for duration of a minimal current draw. Of course, clocks and watches can run for years on button cells, too. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [February 22, 2015, 5:42am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/7 "2015-02-22T05:42:01Z")
Lantern batteries used to be made using four F cells. What’s an F cell, you say? Well, it’s a lot like a D cell, only taller. F cells haven’t been used for much besides lantern batteries in years, so to save money some manufacturers have switched to using four D cells with spacers instead of using F cells. And even though this has less total battery capacity than a lantern battery with four F cells, they still charge full price for the lantern battery (cheating bastards…). I don’t remember off the top of my head exactly how much bigger an F cell is than a D cell, but I’d expect a lantern battery with four F cells to have maybe 30 to 40 percent more mAh than a D cell, at four times the voltage (since there are four cells inside). A lantern battery with four D cells in it will have the same mAh as D cells, because that’s what’s in them (again, at four times the voltage, so even though the mAh is the same you’ve got four times the total energy, since four cells total). If you ever want to know the mAh rating of a particular brand or type of battery, you can usually find datasheets with all kinds of info on the battery manufacturer’s web sites. In addition to specs like the mAh rating, you can also find things like discharge curves and all kinds of stuff. ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [February 22, 2015, 6:13am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/8 "2015-02-22T06:13:56Z")
Poke around on [Amazon.com](http://Amazon.com). Some of the products specify how many mah they have. [http://www.amazon.com/dp/B00N9XV0RW?psc=1](http://www.amazon.com/dp/B00N9XV0RW?psc=1) ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [February 22, 2015, 9:49am UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/9 "2015-02-22T09:49:27Z")
I believe that one AA battery = 100 jelly babies. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [February 22, 2015, 1:49pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/10 "2015-02-22T13:49:12Z")
> [@The\_Second\_Stone](#): > > Poke around on [Amazon.com](http://Amazon.com). Some of the products specify how many mah they have. [http://www.amazon.com/dp/B00N9XV0RW?psc=1](http://www.amazon.com/dp/B00N9XV0RW?psc=1) Those are rechargeables. Pretty much all of them list mAh. The OP is asking about disposables. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [February 22, 2015, 2:01pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/11 "2015-02-22T14:01:28Z")
Do keep in mind that mAh are not a measure of the amount of energy stored in a battery. Energy is measures in mWh (milliwatt hours). Or Wh, if you don’t like trailing zeroes, I guess, or kWh if you want to compare the cost of batteries to the cost of obtaining the same energy from the grid. To find mWh, you take mAh \* cell voltage. This becomes relevant when you’re comparing capacities between alkaline or NiMH cells and 3.7V li-ion cells. Or just looking at 9V. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [February 22, 2015, 2:59pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/12 "2015-02-22T14:59:45Z")
> [@boffking](#): > > I would argue that the chemistry of the battery is more relevant than the size. both are relevant, but that’s another _it depends._ Cell chemistry dictates the voltage of each cell, and can also determine the capacity. for example a nickel-cadmium AA cell is nominally 1.2 volts, and about 800 mAh of capacity. A nickel-metal hydride (NiMH) AA cell is also nominally 1.2 volts, but they have up to 2500 mAh of capacity. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [February 22, 2015, 4:46pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/13 "2015-02-22T16:46:03Z")
> [@boffking](#): > > I would argue that the chemistry of the battery is more relevant than the size. Agree, and I should have prefaced my comment with, “for a given chemistry.” ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [February 22, 2015, 5:18pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/14 "2015-02-22T17:18:21Z")
> [@Gorsnak](#): > > Do keep in mind that mAh are not a measure of the amount of energy stored in a battery. Energy is measures in mWh (milliwatt hours). Or Wh, if you don’t like trailing zeroes, I guess, or kWh if you want to compare the cost of batteries to the cost of obtaining the same energy from the grid. To find mWh, you take mAh \* cell voltage. This becomes relevant when you’re comparing capacities between alkaline or NiMH cells and 3.7V li-ion cells. Or just looking at 9V. Interesting. Anyone know of a reference to the various measurements (mAh, mWh, versus various “sizes”, versus chemical compositions, etc.) of typical retail batteries for the average person? An Idiots Guide To Batteries so-to-speak? ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [February 22, 2015, 5:39pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/15 "2015-02-22T17:39:51Z")
Well, the translation from mAh to mWh is simply a function of Ohm’s law. Watts = Volts \* Amps. Why battery specs state amp hours instead of watt hours has always been a mystery to me, particularly in the case of li-ion cells where equivalent amp hours compared to a NiMH cell equates to three times the stored energy. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 22, 2015, 5:44pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/16 "2015-02-22T17:44:03Z")
> [@engineer\_comp\_geek](#): > > Lantern batteries used to be made using four F cells. What’s an F cell, you say? Well, it’s a lot like a D cell, only taller. There also used to be a 90V battery (for mini-tube radios and the like) that looked a lot like a 9V rectangular battery, only taller and beefier. I bring this up to advise you that you should never, ever do the touch-it-to-my-tongue test with one of these batteries to see how good it is. Fortunately, the one I did it with was almost completely dead, and so merely knocked me on my 12yo ass. :smack: ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [February 22, 2015, 6:09pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/17 "2015-02-22T18:09:11Z")
> [@Amateur\_Barbarian](#): > > There also used to be a 90V battery (for mini-tube radios and the like) that looked a lot like a 9V rectangular battery, only taller and beefier. > > I bring this up to advise you that you should never, ever do the touch-it-to-my-tongue test with one of these batteries to see how good it is. Fortunately, the one I did it with was almost completely dead, and so merely knocked me on my 12yo ass. :smack: you can still find them here and there. > **[Small Battery Company - Built-to-Order batteries for speciallist applications](https://www.smallbattery.company.org.uk/sbc_built-to-order_catalogue.htm)** > > Watch, photo, hearing aid and other small batteries for sale on-line. Free delivery in UK. A bargain camera, button cell or lithium battery. Credit and Debit cards accepted. RS Electronics in my area had the 22.5, 45, and 90 volt Evereadys at least until a couple of years ago. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [February 22, 2015, 7:39pm UTC](https://boards.straightdope.com/t/how-many-mah-do-batteries-have/713303/18 "2015-02-22T19:39:06Z")
> [@Amateur\_Barbarian](#): > > I recall a simple LED flasher circuit that was estimated to run a year on a D cell. That’s the best example I know of for duration of a minimal current draw. Of course, clocks and watches can run for years on button cells, too. The Clarendon Dry Pile, aka The Oxford Bell. Since 1840, maybe 1825.