I confirm that behaviour with the Clip+ … while connected to the PC’s USB port it only displays the “Connected/Charging” screen alternating with the Sandisk logo, and it is not possible to use it for anything else because none of the controls have any effect at all.
In other words, it’s impossible to find out how much recharging has occurred, and you just have to guess how long might be needed and how much charge the player currently has. Not very clever Sandisk
Oh, and while I’m here … the battery doesn’t last anything like 15 hours between recharges. I’ve only had mine a couple of weeks, so I’m not 100% sure what my timings are, but it’s more like 5 or 6 hours. Admittedly, I’ve filled my player up with Ogg Vorbis format music, which I gather (from other threads here) makes the player work harder (= uses more juice).
Lastly, that battery charge indicator in the player’s display is a little weird (where weird = “logarithmic” ?). It takes about 4 or 5 hours of playtime to run the indicator down by 50%, but the next 50% just rushes past in about an hour.