The meter going red is not because of the batteries storage capacity but more the batteries ability to deliver istantanious current.
On lipo batteries it is written as C rating.
1600 should be plenty but the duration will be effected by what what airplane, what servos and how you fly.If you are flying a giant scale 3D airplane with all high torque digital servos and are flying it to its limits, you may only get one or two flights out of that pack.
Medium size sport plane with standard analog servos and limited aerobatics you can probably get 5 or 6 flights or more.