Agreed with everyone before me and I had troubles with the USB charger off my regular desktop as I don't think it's a fully powered (5v DC) USB connector. I did however go out and at Staples or Office Max picked up an older (USB 2.0 spec) 4 port USB hub that had a power plug. I think it was 19$ roughly.
Since then I can easily relocate and plug up to 4
batteries at once to charge and they get done much quicker than trickle via the computer USB. I do know some newer PC's come with a dedicated "powered" USB which is the same but I don't like having 1100mah plugged into my work laptop
Works great and just have it plugged into the wall AC and not computer. Easy Peezy..