On Mon, 28 Sep 2009 14:01:12 +0100, David J wrote:
Looking at replacing the AAA NiAh rechargable batteries in a Binatone
phone. They seem to have lost some of the original capacity when used
during calls.

Originally supplied with 2 off 1.2v 650 mAh.

What is the significance of the last value? Could a 1000mAh be used
instead. Would that increase the 'storage' period?

It's a very coarse indication of how long they will work, under load.
However a lot of battery makers consider this figure more of a marketing
tool - which allows them to charge more, simply by writing a bigger
number of their products. It's almost impossible to verify the mAh rating
of a battery as there are too many variables and dependencies on how it
is used. A higher value may mean the batteries will supply more juice,
ot it may just mean the manufacturer is less troubled my a conscience
than others.
However, the capacity of even good brands can be killed by having a poor
charger in the phone's base - in which case no amount of mAh will help,
if the phone overcharges and thereby destroys the batteries.