General problems with charging cell phone... (I have Samsung a717)?

[Shin K]

I've recently owned a Samsung a717 from ebay (brand new). I've already ordered a new battery and both times for some odd reason, the fully charged battery will last no more than 10 hours, WITHOUT texting or talking.

I've read somewhere that it can also be the 3G network that drains the battery like no other and all other settings like brightness and bluetooth I was careful enough to turn down/off.

But if I've ordered another battery that's still having the same thing, is it the phone's design problem or simply something wrong with the one I have? Phonearena says the phone is supposed to have a standby time of 10 days.