Any question answered...

Watch out, the mAh ratings of those things are often speced as the mAh capacity of the thing's internal 3.7V battery rather than the number of mAh that you'll get out of it at 5V.

See the first link for the biggest one - 30000mAh cell rating becomes 16800mAh true output. But then the 1100mAh internal unit is probably a cell rating too.

Cheers, they're all a bit bulky though. I wanted to use it for on the go charging like the Garmin device that straps to the bars. I guess I could strip the case down and repackage the cells.

The more capacity, the bigger they get. There's no getting around the basic physics.