how to work out a capacity of a battery

thanks for the info, going to try to test the battery im going to aim for a 250ma load using suitable r (high wattage r), 5w 20 ohm.

i stumbled across this guys site if anybodys has any interest in batterys capacitys, this guy must have tested every battery available amazing

http://lygte-info.dk/info/Batteries2012Info%20UK.html

(im never ever going to get in an plane comming out of china im sure the holds are full to the brim with these batterys id rather walk)

thank you