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barjohn

macrumors newbie
Original poster
I have now observed on numerous occasions that the battery level will drop significantly when the iPhone is connected to iTunes and you are either synching or performing a restore. I have seen it drop from 3/4 to less than 20% on some occasions. I can't figure out why since it is also showing as charging.

Anyone else notice this?
 
My roommate's seen that too.

My guess is that although the iPhone is charging while syncing, the drain from writing the data to the flash memory drains the battery faster that the USB cable can replenish it.
 
I've started to notice this on my iPhone recently....I'm pretty sure this is new. Sometimes it even loses the charging icon on in iTunes(so its just the battery bar)

Weird!
 
I have now observed on numerous occasions that the battery level will drop significantly when the iPhone is connected to iTunes and you are either synching or performing a restore. I have seen it drop from 3/4 to less than 20% on some occasions. I can't figure out why since it is also showing as charging.

Anyone else notice this?

On Windows you can set your USB ports to not shut down to save power. You can also check to see what devices are on each port and how much power they use. I assume you are not using a non-powered USB hub?

I remember back when I used a Blackberry the driver would step up the juice through USB. Anyone know if the iPhone drivers do the same thing?
 
After posting this, I left my iPhone connected to the iTunes figuring it would charge back. Instead, the battery level dropped even further. I have seen this too once before but thought I was imagining things.

I then took it and plugged it into the wall on the charger to recharge the device. I was going through a non powered hub so maybe that is the issue. Nothing else was connected to the hub and in use.

I will see if a direct connect resolves this issue.
 
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