I like to test things before I go on a trip. I was hoping to go on a trip without my laptop (this may be the first in years for a week-long trip), and I wanted to be sure I could charge my Treo from my iPod's wall charger (a small adapter from wall current to USB). Cell phones come in handy on the road, at least while the battery lasts.
My Treo 700p failed the test! It would not charge from anything but my actual laptop. The closest I could come to faking it out was to plug a powered USB hub into my laptop, plug Treo cable into hub, plug Treo into cable, let Treo start charging, and then sneakily unplug the hub from my laptop. That's a lot of hassle just to get it to charge!!!
I'll just bring the spare battery instead, but it's annoying not to be able to charge how I wish, so I had to ask Google why. From Treo charging in cradle from Palm Support Forums:
Besides using the charger to charge the phone, the PC will need to be on to use the trickle charge method. Some motherboards can allow continuous current even if PC is shut down but clearly your PC does not have such motherboard. The reason why your powered usb hub is not charging the phone is that the hub itself regulates power by "On Demand" and that demand is active data xfers from A to B or vice versa. So if no data is moving, then there will be insufficient power from that usb port to initiate a trickle charge.
Phooey. At least the mystery is explained; too bad my Treo wall and car chargers died (I think it wears out the connectors somehow since new cables work, but that's another story).