iPod Please help me fix my iPod Nano!

[2thousand9]

I have the 4GB square lookin iPod Nano, and untill recently it was working 100%. Then one day, it just wouldnt start up. Whenever I plug it into the computer I have to remove my mouse or keyboard or it will say too much power. and trust me my usbs are fine I run all kinds of other **** thgough them. if I plug it into the dock, it will start up, and run properly but as soon as I unplug it, it shuts down, instantly. Then too turn it on I need too plug it in somewhere again. Sometimes, when I unplug it, it will remain on. It says the battery is almost full (probably because it was just in the dock for a while, but then it instantly shuts down once again. One time i unplugged it and it worked, and just when I moved the headphone cord it turned off. What is wrong and can I fix it??? PLease help mehhhhhh

 

[rgarjr]

could be a bad battery.