Divide by average discharge voltage:
= 1820 / 3.7
= 492 mAh
So the absolute theoretical MAXIMUM mAh of a lithium ion rechargeable battery is:
Then consider the fact that this calculation fails to subtract the volume of metal making up the casing, contacts, protection circuit (if there is one), and further that it represents the HIGHEST POINT in an energy density range for li-ions that on the low end is less than half the figure used here.
In other words, I would be surprised if a 10440 exceeded 350mAh. And my math may be totally wrong. I just pieced this together out of intrigue, from a bunch of different sources. It was fun. It could be totally incorrect