Why do battery leaks still happen?

What would happen if I send my iPod for battery replacement?

• I'm still in warranty, but my battery life is short. According to Apple, my iPod touch 4th gen has 40 hrs of music, but I have less than 20, which is less than half of battery capacity. If I send it in for replacement but Apple claims that the battery has longer life than I tested, would they charge me, or would I be able to choose if I want the battery replaced or not? I followed all of the steps Apple has on the website in testing the battery, and I don't want to spend $70 on a battery.

• Answer:

  Mh, this is tricky as if you send it to someone other than Apple, you will have to pay and your warranty for the iPod will be void as it will have been tampered with. If you send it to Apple on the other hand it all depends on what they want to do, if they find nothing wrong with the iPod it should be fine and they should send it back however they may ask for a charge for wasting their time, if something is up with the iPod's battery then yes it should be free as you still have the warranty, however make sure it isn't your fault the battery life is short other wise they could say you have tampered with it and therefore say they will not repair it. I hope this helped :)