Charging via PC while it's not on

[beowulf7]

I noticed something odd in regard to charging my phone w/ my PC. With my previous phone, I was able to charge it with the micro USB cable even when my PC was off/hibernate/sleep (I know they're not the same things). With my Droid 3, however, if my PC was off and I connected the micro USB cable, it didn't charge it.

However, if I connected my phone to the PC while the PC was on, and then hibernate the PC, it kept charging my phone overnight. Did anyone else make this observation? It's odd how the phone doesn't get the power from the PC's USB when the PC is off, but does so when it's on and then is turned off while the cable remains in tact.

 

[imnotmikal]

It's because when it's off, it's... well, off.

In hibernate, the computer is still powering USB ports, and still technically ON.

Plug in your phone while it's on, and then completely shut it down. I can assure you it will not continue charging.

 

[beowulf7]

It's because when it's off, it's... well, off.

In hibernate, the computer is still powering USB ports, and still technically ON.

Plug in your phone while it's on, and then completely shut it down. I can assure you it will not continue charging.

On my old phone (LG enV Touch), it would charge regardless of if I plugged it before I turned off/hibernate the computer or not.

The next time I turn off my PC (not hibernate), typically when it requires a reboot after a Windows update, I'll try out my charging tip to see if it still does charge.

 

[sharkh20]

On my old phone (LG enV Touch), it would charge regardless of if I plugged it before I turned off/hibernate the computer or not.

The next time I turn off my PC (not hibernate), typically when it requires a reboot after a Windows update, I'll try out my charging tip to see if it still does charge.

That shouldn't have anything to do with the device you plug into the USB port. The ports should be powered off when the computer is powered off.

 

[fildrigar]

My old Droid ( and my new one, for that matter. ) did the same thing.

 

[JoeFishNC]

If you have a Powered USB HUB then it will power the phone regardless if you have your PC on or now. That is what I have to charge my phone plus the HUB sits on my desk which makes it convenient.

 

[sharkh20]

If you have a Powered USB HUB then it will power the phone regardless if you have your PC on or now. That is what I have to charge my phone plus the HUB sits on my desk which makes it convenient.

Pretty sure if he had a powered USB hub, it would charge his droid 3 just fine. I never charge my phone using the computer anyway, takes FOREVER.

 

[beowulf7]

That shouldn't have anything to do with the device you plug into the USB port. The ports should be powered off when the computer is powered off.

I can assure you that my USB ports are powered on even when the PC is turned off or put in hibernate. How do I know? Well, in addition to the charging my previous phone that I mentioned, one of my USB cables has a blue light emitting from it. The only way that light goes off is if I unplug the PC (or power off the UPS it connects to) or turn off the PSU from the back of the PC.

If you have a Powered USB HUB then it will power the phone regardless if you have your PC on or now. That is what I have to charge my phone plus the HUB sits on my desk which makes it convenient.

Yes, that's what I thought, but somehow that doesn't seem to be the case if I turn off/hibernate the PC and then plug in the phone. If I do it in the reverse order, then it charges my phone no problem.

 

[aostang]

Some laptops, including one that I own, have an option in the BIOS to leave at least one USB port powered while the laptop is off to allow a device to charge off of it. This doesn't really apply to what the original poster noticed, but I just thought I'd mention it with some people saying "off is off".