I need to reduce a battery output of 14.8V to 9V. A simple 9V battery wont work, need to reduce existing. 7809? or different one?

 

I need to reduce a battery output of 14.8V to 9V. A simple 9V battery wont work, need to reduce existing. 7809? or different one?

You didn't tell us how much current you require, a 7809 MAY do what you want.

 

What is your load? (mA?)
A square cooky 9V battery, it only can providing a small current, that is designed for a light load.