I have recently been VERY frustrated with the charging of the phone. I have done some testing and would like to report my results.
First of all I have the 2.01 update installed because I believe that makes a difference. Before the update, the phone would charge, though slowly, connected to my computer via usb. It wouldn't even have to be on the back of the computer. It would charge connected to my monitor hub. Any ways...here are my test results.
There are several variables that seem to effect charging effectiveness.
CF - Factory2. Source
CO - Other
SDD - Desktop DirectKeep in mind these are estimates, but empirical.
SDH - Desktop thru some sort of hub
SL1 - Laptop #1 Direct (my home laptop W7)
SL2 - Laptop #2 Direct (my office laptop XP)
SWF - Wall charge unit
SWO - Wall Other unit (after market wall chargers are plentiful).
SCO - Car Other (after market car charger)
CF - SWF : + 1% / minute
CO - SWF : + 1% / minute
CF - SL1 : +1% / 10 minutes
CF - SDD : -1% / minute
CO - SDD : -1% / minute
CO - SCO : +1% / minute
CF - SL2 : 0%
I will continue to update my results. But the bottom line so far is....connect to the Factory Wall Charger or Any Car Charger if you want to charge your phone.
Update 12/23/2009: I've been experiencing some mixed results with charging.
For a week or so the phone was charging beautifully...actually charging thru my USB at work thru a Hub even.... CO- SDH...
But today it actually DISCHARGED and pretty rapidly while connected to the same USB port.
My suspicion is there is an application that is running (perhaps a widget) that is pulling too much power. I have a suspicion...and will report back.