i have a mp3 player but it has really bad battery life. it charges though a usb plug. so i was wondering is their any portable thing that i can put normal aa battery's in it and it will charge my mp3 though usb on the go?
I have never seen an mp3 player that would take a charge while playing. I have seen USB chargers that plug into the wall but even they are rare. Only the Chinese sell them. Everyone else wants you to buy a charger for each USB device you have.
