Help USB connections/questions

[2ndsout]

I have a question regarding the USB connection. My wife was using her Droid 3 last night and had changed the USB setting in the phone to be charging only. Although when she had it plugged in via USB; she was still using her phone. The phone wouldn't charge, and we switched it to a few of the other USB connection points on her laptop (all of these USB connection points work properly too). Once she was done using her phone, it started to charge properly.

Does the Droid 3 have a built in function that turns the charging ON after you are done using it? I've noticed that when I have plugged mine in through a regular AC outlet, I am still able to use my phone and it charges at the same time... or did my wife's phone just get plugged up running some apps ??

Any ideas?

 

[Unicorn512]

The USB connection seems to charge at a much slower rate than the power plug connection. So while you are using it you are draining power and I suspect that depending on the apps involved, you might even be able to drain faster than charge in some case. I sometimes see this using my car USB connection while playing music and navigating.

It's the old "is the hole in the bucket bigger or smaller than the faucet spigot" issue.

Sounds like everything is working as designed.