Unhappy [Q] [HELP] Samsung Galaxy Ace GT S5830 screen problem

I recently purchased Galaxy Ace then I lost its battery immediately after purchase replaced it with a perfect batt from Galaxy Y Duos which lasts almost a day on heavy use on Y Duos... My problems are that the Y Duos batt in ace is soooooooo pathetic that it lasts less than an hour, Again if I I'm in a 2G network area my Ace touch screen seems to misbehave pretty weird touching itself every now n then but when I'm in 3G network it works just fine except for the batt drain