Battery Low [Q] How to disable Hsdpa ?

Hello!
I want to disable Hsdpa form my i9190, in order to save battery life by keeping only 3G.
I have tried some solutions, like the secret codes (*#301279#, ...) and other apps without no succes.
Now im aksing you guys to help disabling Hsdpa !
I'm running on 4.4.2 (Jelly Bean) with this ROM : I9190XXUAMF7
Thanks !!!!