Hello mjsbaby513,

According to the tech specs on apple.com, the iPod Nano 4th generation can play videos in various formats, such as .mov, .mp4, .mv4, MPEG-4, just like the iPod Nano 5th gen.

A full battery charge can render about 4 hours of video playback.

If you are considering purchasing an iPod Nano, you may also want to know that the iPod Nano 5th generation is also equipped with a VGA camera and a 2.2 inch display with TFT background. On the other hand, the Nano 4th gen has a smaller display (2 inch) but with LED technology, so it consumes a little less power, and has brighter colors.

If you want more technical details about the iPod Nano 4th gen, you can visit http://support.apple.com/kb/SP497 .

Hope this is everything you need to know,

Collin Hilder