ipod touch 4g battery indicator shows incorrect information

Hi,
I have recently bought an Ipod touch 4g.. os: 5.0.1. I have tried finding a solution to this problem but couldnt find any info about it anywhere.
the problem is my battery indicator shows wrong information.while listening to music it shows proper percentage.and if i turn on a game, the percentage drops rapidly.then if i close the game and lock the screen then the battery percentage gets increased again.
it's showing wrong battery information almost always. "20% battery remaining" pops up whenever i use an app for 5/10mins. then after closing the app it shows an increased percentage! it's very confusing. do u think something is wrong with my battery or is it the ios?
i don't think the battery is malfunctioning as it works perfectly normal when i listen to music and also percentage gets increased as soon as i close an app other than music.
please help me out. I have already ordered a new battery as a backup

Hello and welcome,
Battery indicators can be notoriously fickle, particularly if it's not a 'smart' battery similar to the ones you would find in a macbook. Then again it could be an indication that it's not taking a charge properly so you are right to be on guard. Those gaming apps really do suck some juice though.

If things aren't working as they are you might want to perform a restore back to factory settings through iTunes, do a full sync and see if it stabilises. Back everything up first though.

I agree with Pendlewitch that battery run-time is not a precise science. Most devices have some mechanism for "guessing" as to how much runtime your battery has, but it takes time to learn your usage patterns and how the battery reacts to them.

You may try "calibrating" your battery, by starting with a full charge, using the device until it turns itself off and then letting it sit and fully charging before using it again. This should help make the runtime indicator more accurate.