"Not Charging" but actually charging?

wrkactjob

macrumors 65816
Original poster
Feb 29, 2008
1,357
0
London
Anyone else find that when their Pad is USB connected to a PC or laptop it states "not charging" but does actually charge?
 

stix

macrumors member
Aug 2, 2010
83
0
Helvetic Confederation
Sort of. What I've found is that when the screen is on, it's really not charging - as it very kindly tells you. Turn the screen off and it starts charging (albeit slowly). I assume that in the darkness it says "charging" but you can't see it because the screen's off. It's like the light in the fridge.
 

wrkactjob

macrumors 65816
Original poster
Feb 29, 2008
1,357
0
London
Sort of. What I've found is that when the screen is on, it's really not charging - as it very kindly tells you. Turn the screen off and it starts charging (albeit slowly). I assume that in the darkness it says "charging" but you can't see it because the screen's off. It's like the light in the fridge.
Ah I see! I kind of presumed that the 'not charging' applied if the screen was on or off, but as I noticed this morning that after a night leaving it having synched up it was in fact at 100%, so yes what you say makes sense!
 

lokerd

macrumors 6502a
May 2, 2010
589
1
Beaumont
If you go into a "Info" app, that reports the status of the battery, you will see thatit is charging even if on. I have left mine on, with "Not Charging" and it is taking a small charge evidenced by the 100% at the end of a work day being plugged in all day when I had forgotten to charge the night before.
 

NDimichino

macrumors 6502a
Jan 14, 2008
593
0
New Jersey
If you go into a "Info" app, that reports the status of the battery, you will see thatit is charging even if on. I have left mine on, with "Not Charging" and it is taking a small charge evidenced by the 100% at the end of a work day being plugged in all day when I had forgotten to charge the night before.
Anyone know why it doesn't charge via computer/laptop USB?

I know the thread is suggesting it does, but why the designed "Not Charging"?
 

MCRunning

macrumors 6502
Sep 8, 2008
324
0
Anyone know why it doesn't charge via computer/laptop USB?

I know the thread is suggesting it does, but why the designed "Not Charging"?
Do you have it plugged into a USB hub? There might not be enough power to charge it
 

NDimichino

macrumors 6502a
Jan 14, 2008
593
0
New Jersey
Do you have it plugged into a USB hub? There might not be enough power to charge it
I have a MacBook, but have also used my desktop at work and still "Not Charging" appears.

Thought it was quite strange for Apple to now allow one of its products to charge with a computer via USB. We don't always have outlets.
 

mklnk

macrumors regular
Apr 14, 2010
154
0
I have a MacBook, but have also used my desktop at work and still "Not Charging" appears.

Thought it was quite strange for Apple to now allow one of its products to charge with a computer via USB. We don't always have outlets.
It's not about Apple not allowing it, it's about the voltage (or wattage, or amperage... ask an electrician) of the USB port. The newest apple computers have these high power USB ports that will charge the iPad, but most other computers do not.

And, I had always suspected that any old USB port would charge the iPad, but that the power coming in would not be enough to tip off the OSes little "I'm charging" indicator. I will have to test it myself now that others are seeing this.
 

NDimichino

macrumors 6502a
Jan 14, 2008
593
0
New Jersey
It's not about Apple not allowing it, it's about the voltage (or wattage, or amperage... ask an electrician) of the USB port. The newest apple computers have these high power USB ports that will charge the iPad, but most other computers do not.

And, I had always suspected that any old USB port would charge the iPad, but that the power coming in would not be enough to tip off the OSes little "I'm charging" indicator. I will have to test it myself now that others are seeing this.
Interesting, I thought a USB was a USB. Thanks for the insight. Definitely post your findings.
 

tbrinkma

macrumors 68000
Apr 24, 2006
1,651
93
I have a MacBook, but have also used my desktop at work and still "Not Charging" appears.

Thought it was quite strange for Apple to now allow one of its products to charge with a computer via USB. We don't always have outlets.
The batteries in the iPad require a higher amperage than a normal USB port will produce to charge at any reasonable rate.

Your bog-standard USB port produces 500mA @ 5V.
The iPad charger does 2.1A (or 2100mA) @ 5V.
An iPhone charger does 1.1A @ 5V, as can the USB ports on newer Macs (and even a few PCs).

Charging an iPad on 500mA may be possible, but it isn't going to happen fast enough to be useful unless you leave it plugged in for *hours*. It sounds like the iPad errs on the side of caution, telling you it isn't charging even when it actually is charging *very slowly*.


Note: Being able to provide 1.1A over USB doesn't violate the standard, so long as it isn't provided unless the device specifically *asks* for that much juice. It's just that the USB spec only *requires* being able to provide 500mA.
 

sammcj

macrumors member
May 10, 2009
62
16
Australia
If you've running winblows download and install this: http://event.asus.com/mb/2010/ai_charger/

It will work on a lot of non-asus boards too. (Works really well on my work's HP computers fine)


If you're on a Mac, or a Hackintosh (Like Moi) I went out and bought a 2x USB Male to 1x USB Female. That way you can plug it into two usb ports and provide enough power to charge properly.
 

vidsmart

macrumors member
Mar 16, 2010
46
21
My iPad ran out of juice at a conference yesterday and I tried one of those small portable chargers I carry for my iPhone. After a few minutes, the screen came back on and though it read "Not Charging" it continued to charge up to about 10% by the time I returned to my hotel room where my a/c charger was.
 

jdong

macrumors member
Nov 24, 2008
33
0
As stated by others, "Not Charging" simply means "The device isn't receiving enough power to charge at a fast pace that you'd expect"

It doesn't mean the device is downright refusing to take power.

With your USB port, your iPad will try to take as much power as it can negotiate from the port. If that value is 500mA or less, your iPad often uses more than 2.5W power when the display is on, in which case indeed your battery might even slowly drain while your iPad is plugged in.

It's a good idea to warn you when you're plugged in but not receiving enough current for fast charging. Maybe "Not Charging" isn't the best wording for that notification though.
 
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