I have an unlocked Galaxy Ace Q i827. Battery drain issues COULD be with your sim card. After installing the Petro Can sim, the battery would drain fast--about 5 or 6 hours. After several days of searching, I found out it could be the sim card causing a short somehow & draining the battery---even when it's off!
Try taking out the sim card & monitor the battery drain. If you find your phone lasting longer, than you know it's the sim card. Then, try this. Disable all wifi, Bluetooth setting etc. Shut down the phone. Re install the sim card. Make SURE, it is installed correctly & all the way. Power up the phone. I just did this procedure & my phone has been sitting at 74% power for about 1/2 hour now. I may be on my way! Good luck~