AA batteries and AAA batteries - difference in duration

[Jurek]

Does anyone know, perhaps as a percentage, how much less use I'm likely to get from 4 x AAA's as opposed to using 4 x AA's - needless to say, with the same load?

Cheers.
J

[rogerzilla]

Are they rechargeable?  If so, it's just the ratio of the mAh capacity.  If not, maybe half.

[border-rider]

It's still a matter of the mA h capacity, rechargable or not.  Just that you might not know it if they're non-rechargeable.

As RZ says, it's about a factor 2, maybe slightly more,  but it'll vary quite a bit between different types & makes and what you get in practice may be somewhat different than theory, because the capacities are dependent on discharge rate, and smaller batteries may be unhappier at higher discharge rates

[Jurek]

Thanks for that - I had a feeling it would be somewhere in that region.
We're talking standard alkaline manganese, non-rechargable Duracells, BTW.

However, I had a much stronger feeling that the first to reply to my question would be one or the other of you two gents.
Make of that, what you will.  

Cheers

[TimO]

The volume of an AA is almost exactly twice that of a AAA cell (the variability in the exact dimensions of the cells take the difference either side of two).  In principle this should mean that the capacity of an AA would also be twice that of a AAA, but as the cell gets smaller, probably proportionally more of the battery is wasted on non-productive parts such as the case, so the capacity of an AAA will probably be less than half that of an AA.  The figures I've found seem to suggest that this is typically the case.

[Jurek]

Thanks for that TimO.
Believe it or not, when I was thinking about this, before I posted, it did occur to me to a) weigh both batteries, and b) dunk them in a calibrated jug of water to see how much was displaced - and try to work it out from there.

But then I thought the answer to this will be an electrickery one......

[Dave]

If it's any help, the AAA rechargeables I've got are 900mAh and the equivalent vintage AAs are 2500mAh.

[Greenbank]

If it's any help, the AAA rechargeables I've got are 900mAh and the equivalent vintage AAs are 2500mAh.

1100mAh and 2850mAh are about the limit of (AAA and AA) rechargables available now.