Can your iPhone 4 charge while turned off?

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Level 1

0 points

Can your iPhone 4 charge while turned off?

When iPhone is charging while turned on, the battery is charging AND discharging at the same time (because the phone is always fonctioning and consuming battery power even if it's sleeping). That's not good for the overall battery lifespan in the long run, am I right? As far as I know, only the China Unicom iPhone 4 model can charge while turned off (see http://support.apple.com/kb/HT1476). Do you think the fact of charging while turned on will ever have an impact on its lithium-ion battery?

iPhone 4, iOS 4

Posted on Sep 28, 2010 1:43 AM

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Answer 1

Sep 28, 2010 2:22 AM in response to ispriteu

Apparently they no longer charge when turned off (except in China).
<http://discussions.apple.com/thread.jspa?messageID=11868363&#11868363>
I never turn mine off, so didn't notice the change.

In any case, the battery is not being discharged if the phone is on while charging. Some power from the charger is used to run the phone; the rest is used to charge the battery.

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Answer 2

plcn

Level 2

325 points

Sep 28, 2010 4:16 AM in response to ispriteu

You can charge it turned on or off. You can do it with any iPhone in any country

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Answer 3

Kwopau

Level 4

1,742 points

Sep 28, 2010 7:40 AM in response to ispriteu

Sometimes I turn my iphone off completely. Before charging, I'm around 40% then i turn it off while charging, and when I turn it back on in the morning, it reads 100% and is fully charged. So technically it should still charge when turned off.

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Answer 4

Sep 28, 2010 8:38 AM in response to Kwopau

Before charging, I'm around 40% then i turn it off while charging, and when I turn it back on in the morning, it reads 100% and is fully charged.

That's how it should work, but there are some reports of it not, and there is the Apple reference to it only working on Chinese iPhones. Maybe it's just some iPhone 4s. My 3GS with 4.1 does charge when off. (Connecting the charger turns it on, so you have to turn if off after connecting.)

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