I don't have a sophisticated cellphone, but my battery had to be recharged daily, instead of weekly. They told me to take the battery out for half an hour and then put it back in. It has worked fine ever since!
All new technology sucks for a while. You should wait another 5 years for them to figure out how to make android phones last longer.
Make sure you keep your GPS and wifi disabled if your not using it. Akso check running apps for any non 'crapware' (default sw your phone came out with) that is perminantly running and remove it. All in all if you get a full day you should be happy (Thinking big screen phone like S2/S3)
my wife had that problem, not sure but it may have been something about the wireless setting. anyway she took it back to the store and they did something and it worked ok afterwards