USB port draining battery?

Michael Mays wrote:
Does the USB port drain the battery when the computer is asleep or turned off?

I had this same issue ( http://discussions.apple.com/thread.jspa?threadID=1148247&tstart=0), but didn't get an answer other than make your computer not sleep, which is kind of a lame solution.

"The computer goes to sleep."




If your computer goes into sleep mode, it is not charging your iPhone. The reason it is discharging though is probably due to your leaving on WiFi, automatic checking of email...etc., that type of thing, although, it shouldn't drain that quickly I don't think. Have you charged it up correctly at all since you got it?

Michael...While your computer is in sleep mode...it still uses power...this power can be drawn from any source and since USB is not just one way, the computer is therefore drawing power from your iPhone and draining it while it sleeps. If you charge at night, I recommend that you either change your settings on your computer or use the power brick. Hope this answers your question.

Good Luck

🙂 Ok, well I didn't think that the drain was normal, but I also don't think that it is because of the USB port that it is draining either. It's not going to charge when your computer is in sleep mode either, at least that is the way I understand it. I myself am at a loss right now as to why it would be draining like that. Sorry I couldn't be of any assistance. Hope you get it figured out soon, and if I think of anything I'll post back.

No....its not a joke...I am quite serious and if you look at same scenarios over the past two months, you will see that others have stated the same thing. The computer will and does draw power from any source available while in sleep mode. I do not joke when trying to assist users.

Well, I've never heard of such a thing in the last 25 years or so of being a pc/mac owner (mac's just recently :)) If this type of thing is actually transpiring, then I would say that there is something terribly wrong with said equipment. I've had the same scenario (devices connected to my usb port while said computer/mac is sleeping) over the last 25 years many times and the draining of any devices on the port has NEVER occured.





I realize that power flows through the usb port both ways, but the usb port was never designed to DRAW power from the devices that are attached to it, in fact it is the OPPOSITE. Again, if this type of thing actually is occuring, then there is definately something wrong (unless all of my purchased pc's/mac's have been the exceptions to the rule - which I very much dought).





If all of my computers have been the exception, then please someone else chime in here and let me know.

I am not going to sit here and argue with you...if you do a search on this forum and subject you will see that there is a consistant pattern of discharge of the iPhone while a computer is in sleep mode or has been turned off...this is causing the iphones battery to "discharge". I don't know if your computer(s) are the exception, they are not here in front of me. The OP asked a question, I gave him an honest assement based on the threads in this forum. It is up to him if he accepts the answer...in any event, he has the option to change the settings on his computer to allow it to remain running overnight, thus not draining the iPhone battery or using the power block.

Response is not neccessary as I will not reply.

Sorry, but I've got to reply for everyone elses sake that wants to know what's up with this thread/comments/questions/etc. If you are basing your comments on what is in this forum, then you're picking a lousy source of information. I'm not pointing the finger at ANYONE, but anyone can come in here and post whatever the heck they want to, it doesn't mean that it is the truth.
I would suggest that you pick a more reputable source of information if you really want to help the users in the forum. The exception would be knowing FIRST that what you're reading in the forum is TRUE, then pointing them to that information.




Why isn't all of the other USB devices draining then? NONE of mine are. I've got iPhone and the iPod attached to the usb ports on my mac while it is sleeping and neither one of them drain. My pda on my pc is attached all night with computer in sleep mode, it doesn't drain either.




I'm not argueing, I'm stating FACT which is the only way to help others here.

I don't know if it is a joke, but it is nonsense. On the other hand, it is correct that the iPhone can discharge through a USB port, depending on how the electronics of the port is implemented on the host computer, and on the iPhone. So, yes, the iPhone draining its battery when the computer is off points to some lousy design decisions on the side of the iPhone.

Message was edited by: Pirx07

I'm sorry, but I've got to say this but I think your statement is nonsense. I'm talking about a standard USB 2.0 port that by design is going to allow a device that is attached to draw a certain amount of power for operational/charging purposes. The port certainly is not (by design anyway) going to draw power from the device that is attached to it. If a battery in a device that is attached to a usb port is loosing power too quickly, I DOUGHT very much if the usb port has anything to do with it, unless the port is malfunctioning in some way. They are just not designed this way.





Don't take my word for it 🙂 I learned this myself in electronics school (focusing on computer electronics), but you can learn the same thing by googling on USB/USB POWERING ... etc ... etc


Google CAN be your friend if you allow it to. 🙂

Sigh...

I'll just add that it might be a good idea if any of you guys would RTFM, which says, on page 23:

"*Note: If iPhone is connected to a computer that’s turned off or is in sleep or standby mode, the iPhone battery may drain.*"

P.S.: Google can also be your foe, if you don't know how to use it right...

SFC @rcher wrote:
I am not going to sit here and argue with you...if you do a search on this forum and subject you will see that there is a consistant pattern of discharge of the iPhone while a computer is in sleep mode or has been turned off...this is causing the iphones battery to "discharge".

I don't think anyone's disagreeing with the fact that a sleeping computer can drain a iPhone. As you say, there are lots of people reporting just this.

He's taking exception to your explanation of why the iPhone is being drained. The iPhone is not being drained because the sleeping computer needs power. A likelier explanation (which still could be wrong) is that the USB +5V rail is no longer at +5V when the computer sleeps, and so the battery drains through the (now unpowered) charging circuitry. Note that the power just wastefully drains away, and does not go to power a sleeping computer.

QuickDraw wrote:
The port certainly is not (by design anyway) going to draw power from the device that is attached to it.

Um, while the port is not going to draw power from the iPhone, it does appear that the iPhone can be drained by it. The cause could be as simple as a missing diode in the iPhone.

"The cause could be as simple as a missing diode in the iPhone."



🙂 Possibly, can't remember all my training, it's been too LOOOONG since I received it and too long since I've been able to put it into practice. It requires too much precision for these old hands to accomplish. 😉