My ipod's battery is draining fast. I went to an authorized reseller of Apple products here in the Philippines and they said that it is because of the method of charging. They said that when you charge the ipod using the USB port of the computer it charges 80% of the ipod's battery no matter how long it is plugged in the computer. They said that to gain 100% of battery charge, we need to buy a USB power adapter. Is there any difference on the two methods that I have mentioned? Thank you!