Delstar DS 8013 MP3/MP4 Video Player recharging

Question

I want to know how to recharge the battery. In one place in the manual it says to connect USB cord to the computer, then to the player and then turm the player "on". In another place in the manual it says when power runs out, turn on the power switch before recharging or the player may not be recharged. I have tried both ways but cannot get it to recharge very much. How long should it take to recharge? Thank you.