AA vs. AAA vs. D

lundyjb

since they're all 1.5v, whats the difference between them. Do they just have different lengths of life?

berkeman

Yes. Different physical sizes, so different Amp*Hour capacities. You can look at their datasheets at the battery manufacturer websites to see the differences.

You can also get them in Alkaline or rechargable types.

yungman

Here is a link on a lot of batteries and their Ahr or mAhr.

http://en.wikipedia.org/wiki/List_of_battery_sizes

NascentOxygen

I'd expect the physically larger cells to offer a lower impedance, in addition to a longer life while powering a certain load, all other factors being equal.

Enthalpy

They use to. It is the case with AAA, AA, B, C and D alkaline and zinc cells.

It also depends on design choices. More peak power also results from more electrode surface, which can then be thinner and interleaved: this is sometimes done with Ni-Cd accumulators but usually not with alkaline cells, as it also increases the self-discharge.

Studiot

I beg to differ with other esteemed posters here but what makes you think they have 'different lengths of life'?

The length of life depends upon both usage and battery electrical capacity and even upon the definition of the term 'length of life' itself.

Comparing batteries by physical size also runs into the issue of battery chemistry and terminal voltage, some are 1.2 volts some are 1.5 volts etc.

Even with the same terminal voltage chemistry influences the capacity, for instance I have a 1200 mA-hour D cell in Ni-Cad technlogy and a 2300mA-hour AA cell in NI-MH technology. Both offer a terminal voltage of 1.2 volts.

Note also that I use the term 'terminal voltage'. What do you mean by 'length of life'?
A cell will continue to power a torch or clock well beyond its usability for a digital camera.

Studiot

If you would like to rephrase this in English we could help.