Tevion 5937 mp3 player

Question

i have bought 2 of these for my daughters my 2 desktop computers have windows xp home o/s.I have a laptop with windows vista.I have the same problem with both players,the computers recognise them as usb mass storage devices.The battery pic on the player screen flashes and fills up then repeats again and again but after leaving them (as i think ) charging for the whole day whilst at work.after disconnecting them from my computer the players say not charged and switch off. if this was one player then ok but 2 players means i must be doing something wrong.Could anyone help a poor ignorant father with 2 children beying for blood. :>)