Can't Charge Through The Usb

[Blue Ion]

Thing is, I've received my Pandora on Monday and been using it quite happily ever since, so far I've charged it 4 or 5 times, and no problems, the pandora can last 10 hours straight.
However I've tried to charge through the usb several times but to no avail. Only after searching the forums on how to do it and seeing that is just plug and charge, I decided to cry for help.

When I plug the usb cord nothing happens, maybe Windows 7 tries to install a composite driver of some sorts and fails, but thats it. No red light meaning its charging, no output on either dmesg or lsusb (should there be any?), no 00:00 on the time left of the battery, no nothing.
It just sits there draining the battery slowly as it normally does.

I've tried a wall charger, a normal usb, a two headed usb cable (for those power hungry hard-disks), a car usb charger (those that comes with gps navigators) and nothing. In fact, right now the battery just have a 4% of charge left and when I plug the usb in, the pandora turns on, boots up, discovers it has no battery, and shuts down, and stays like that even with the usb cable plugged in.

The only assurance I've have that it is "somehow" plugged is that the Pandora powers up as it does when using the normal charger.

Right now, I have tried putting the Pandora at the bootloader (when you power up pressing the R shoulder button) to see if it makes some kind of difference, in case the os is screwing something, but it turned out the same, just 1% less from the time its been like that.

Halp?

 

[notaz]

right now the battery just have a 4% of charge left

From what I noticed it won't charge from USB when battery is low. Not sure what is the cause of this, maybe hardware refuses USB charge when battery voltage is low. You'll have to use AC charger.

 

[Blue Ion]

Ok then, false alarm. I have risen the level to 27% and it did charge.
I was worried because the wall plug I was using still refused to charge at that level, however I then tried a pc usb using the two headed cable and luckily, it worked as expected. I've used that charger every time I tried to do so that explains why I thought it didn't worked.
Apparently either the wall plug is either defective or has some kind mini device to identify what is plugged in and refuse if it isn't a specific device.
The latter is more believable as it actually draws power: at 26% the pandora says 3 hours, with the usb plugged in, it says 2:44

What is the threshold to make the pandora charge?
I was trying to find it but lost it due to the charger refusing to give juice.

If this is the normal operation of every board? a note at the FAQ at the wiki might avoid troubles like mine in the future.

Thanks for the help.

 

[WizardStan]

Windows does not like to provide the full 500ma that the USB can support unless a driver is installed that explicitly requests it. By default it only supplies 100ma (at least XP did. Can't comment on Vista or 7). I learned this when I got a BlackBerry and tried to charge it via USB. Without Rim's BlackBerry driver it charges very, very slowly, if at all. Googling around this turns out to be a "feature" of Windows, and is actually expected as part of the spec.
100ma is not enough to charge the Pandora. Your double headed cable supplying 200ma might just be enough. I imagine that switching the Pandora into hard drive mode (when ED finally gets around to setting it up so you can do so ) will make Windows supply the full 500ma and charging via USB will be a lot better.

 

[nikkopt]

Just out of curiosity, can you try a cable like this one?

edit: Oppss, didn't read WizardStan's post