A friend ask me, My battery does not last as long as it is expected to, and it occassionally powers down during conversations – Is the battery faulty? This is not only the problem of my friend alone. Thousands of mobile phone users are facing this huge problem. But his mean does not that every mobile battery faulty.
In my opinion it could be that your battery is faulty, or that there is a fault with the handset that is causing the battery to power down faster than normal. You are able to test the battery and perform a check on the handset to diagnose the problem. To have the battery tested and/or the phone repaired please pop into one of your mobile phone service centers. Please ensure that the handset and battery are both brought from the same brand.
Note that Nokia, Samsung, LG, offer a 6-month warranty on are batteries if they are proven to be faulty and are accompanied by a proof of purchase. Some new comers like Intex, Videocon, Micromax, Maxx etc offers 1 year warranty on your mobile phone battery.