iPod touch: charging while sleeping

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Level 1

5 points

iPod touch: charging while sleeping

iPod touch 1st gen. with OS 3.0
Apple Universal Dock
iMac 24" alu intel 3.06GHz with OS X 10.5.8

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A question that's puzzling me:

For most of the time that I've had my iPod touch and current iMac, I've left the iPod in the dock overnight, connected to the iMac which I put into sleep mode overnight.

For almost all of that time, the iPod has been fully charged in the morning, and if I wake the iPod while the iMac is asleep, the 'battery charging' icon has been displayed on the iPod.

Occasionally, I've found that the iPod was down to less that 20% charge in the morning, but that has been the exception.

Now, though, it seems that the iPod only charges when the iMac is awake. Leaving the iPod connected while the Mac is asleep seems to discharge the battery.

I've tried a full reset of the iPod, and restarted the iMac - no difference.

I've read here and elsewhere that it's normal for the iPod battery to be discharged if left connected to a sleeping Mac, but this has not been my experience until now.

Has anyone else found that their iPod used to charge while the computer was sleeping, but stopped doing so? If so, do you know why it stopped, and how to get back to the previous behaviour?

Thanks.
MDP.

iMac Core2Duo 3.06GHz 24", Mac OS X (10.5.8), MacBook Pro Core2Duo 2.4GHz 15" Mac OS X (10.5.8)

Posted on Aug 24, 2009 2:54 AM

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Answer 1

Best reply

Julian Wright

Level 8

35,014 points

Aug 24, 2009 3:32 AM in response to northview

Have you only noticed this after a specific Mac OS update?

It may be a change Apple have made in the OS. Have you got any other USB devices that you can use to check whether they are receiving power whilst the computer is asleep?

I know in the past that Apple has made changes to power supplied to both USB and Firewire devices while asleep, and this is the only thing I can think of that may affect it.

Does it do the same if you plug it in directly, not going through the dock?

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Answer 2

northview Author

Level 1

5 points

Aug 24, 2009 3:49 AM in response to Julian Wright

Good questions.

Well, 10.5.8 was quite recent, and a security update, but I think it was still behaving itself up until Thursday or Friday last week, i.e. as far as I know, the changed behaviour didn't start immediately after the updates.

I haven't tried connecting it directly - I'll do that later today/tonight.

I'll have a think about other USB devices. Not sure off the top of my head.

Thanks.
M

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Answer 3

luvlabs

Level 4

3,620 points

Aug 24, 2009 6:36 AM in response to northview

The standard recommendation is to not leave your iPod plugged in when the computer is in the sleep mode. Most sleep modes de-power the USB ports and your iPod is, in effect, powering USB port. I would suggest you add a powered USB port or use a mains charger (see the Apple Store for suggestions) instead.

There was a change to USB port power with OS 10.5.5? or .6? that did cause some issues - especially if you were plugging into the keyboard USB port.

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Answer 4

northview Author

Level 1

5 points

Aug 24, 2009 8:48 AM in response to luvlabs

Understood. However, the iPod touch has been charging successfully during sleep (apart form isolated incidents) up until a few days ago. This suggests that something has changed.

I have never used the keyboard-based USB ports for the AUD/iPod.

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Answer 5

Chris CA

Level 10

82,434 points

Aug 24, 2009 9:26 AM in response to northview

However, the iPod touch has been charging successfully during sleep

Then the computer was not really asleep.
The drive may have spun down and the display has gone to sleep but if the processor is asleep, the USB is NOT powered (per the USB standard). If you are using a powered USB adapter, that will continue to charge but 5VDC from the iMac USB bus will not be available while the CPU is in sleep mode.
FireWire is powered while the computer is asleep.

A bit of info -> <a href='http://support.apple.com/kb/HT1384">Charging your iPod battery</a>
"Important: iPod will stop charging if the computer, or portable computer, it's connected to enters standby, hibernation, or sleep mode. To charge iPod, connect it directly to a computer's USB port (not a keyboard) and make sure standby, hibernation, or sleep mode is turned off."

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