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Cannot Charge with USB Port - True?
- Thread starter bowlerman625
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Whether or not the iPad will charge depends on how good your computer's USB port is. It only happens to be able to charge on Macs because they're good computers.
All you have to do is "READ" the instructions on Apple's website. The Yahoo reviewer was mostly wrong when he said the iPad could not be charged via USB. This has been covered in previous posts on this thread. Also, if you get the not charging on the display, turn the display off (this was on another thread) since the display uses a lot of power. I assume this means sleep mode. I couldn't get out of the house today so I will be getting mine next week. Other posts have indicated the use of the A/C adapter will charge up to 4 times faster than a powered USB. Whether its 2 or 4 times faster the best way is to use the A/C adapter. Apple's website says you should be able to charge the battery approximately 1,000 times.
Charge rate depends on USB power source
It should charge on most USB sources but the rate will be very low for a USB port that has the standard 500mA power source (2.5 W). The supplied power adapter is 10 watts and capable of suppling 2.1 A which allows a much faster charging rate. Some computers, however, have a much lower power capability and may not provide enough power. In such cases the power may be disconnected by the internal circuitry of the computer to prevent damage. This may be the case with some older machines. Solution is to use a powered USB hub, although this can cause data problems (my iPhone will not connect correctly when using a hub, powered or not). My 2007 iMac and original MacBook Air work fine.
It should charge on most USB sources but the rate will be very low for a USB port that has the standard 500mA power source (2.5 W). The supplied power adapter is 10 watts and capable of suppling 2.1 A which allows a much faster charging rate. Some computers, however, have a much lower power capability and may not provide enough power. In such cases the power may be disconnected by the internal circuitry of the computer to prevent damage. This may be the case with some older machines. Solution is to use a powered USB hub, although this can cause data problems (my iPhone will not connect correctly when using a hub, powered or not). My 2007 iMac and original MacBook Air work fine.
I am using the USB part on the back of my 24" ACD, the iPad charges just fine on it.
Joe
Joe
Hi,
Just to check, I tried the USB port on the back of my MAC Mini (Mid-late 2009 Model) and the iPad DOES charge. I am running the latest updates of Snow Leopard and iTunes.
Joe
Just to check, I tried the USB port on the back of my MAC Mini (Mid-late 2009 Model) and the iPad DOES charge. I am running the latest updates of Snow Leopard and iTunes.
Joe
Hrm just found out mine won't charge off the front or top USB ports on my desktop machine (850w psu, coolmaster case, etc..). That kind of bites as I don't believe any of my rear USB ports (possibly higher power) are free. (have to move some stuff to check).
My Macbook Pro 15" Unibody charges my iPad over USB np. 
The iPad is his younger brother hehehehe
The iPad is his younger brother hehehehe
The ones at the front sometimes can't even power 2.5" HDDs properly. It's normal they can't charge an iPad.
*sigh* Just tested it I can't charge via USB using the rear ports either. Had to disconnect some gear to try it and no joy. It will however charge via the wall plug but the included USB cord is really short. Barely reaches from the bar under my desk to the top of my desk.
Hrm looks like it will charge just fine off my MBP's usb ports (of course my itunes library isn't on it). I wouldn't of thought my laptop's USB ports would be spitting out any more juice than my desktop pc. Its not old. Modern quadcore desktop with a 950w psu (gaming machine). It would of been nice to know this ahead of time so I could of thought about getting a longer cord. Its so short I'm afraid someone's going to knock it off my desk.
I think this answers most questions:
1) Charging via a power point will be twice as fast as USB, even if USB charging does work for you.
2) I doubt the iPhone and iPad adaptors are compatible, they charge at different rates I think.
1) Charging via a power point will be twice as fast as USB, even if USB charging does work for you.
2) I doubt the iPhone and iPad adaptors are compatible, they charge at different rates I think.
The problem is that the battery of the ipad requires more mAh to charge than you usb port can provide, and some computers cant provide this power steady even if you have a big power supply on it. The power on the power supply is more dedicated to the other voltages like 12v and 3.3v of your computer the 5v is mostly used for usb accesories, the more usb items you have on your pc the worse its, I have no problem with that I have been using my ipad for about 4 hours now and I still have 67% of battery left and it charges very quickly using the AC usb adapter.
Despite all the talk about not needing it - i'm very happy i have the other adapter on order!
One will stay on the dock at her desk and one will wander around with her i'm sure. It will actually be better once mine shows up and there is a 3rd one.
One will stay on the dock at her desk and one will wander around with her i'm sure. It will actually be better once mine shows up and there is a 3rd one.
Y adaptor
Anyone tried those "Y adaptors" which provide more power to external hard drives? It should work with the ipad too.
This is what I mean:
![apricorn-aegis-bio-usb-cable.jpg]()
Anyone tried those "Y adaptors" which provide more power to external hard drives? It should work with the ipad too.
This is what I mean:
I can charge fine with my 2006 Mac Pro, plugged into the USB port on the back of a 23" Apple Cinema Display.....with the screen OFF.
People need to keep the iPad screen off and let it sit. It's going to be slow over USB regardless. I've heard (from Andy Inhakto) that charging via the power adapter takes up to 4 hours....and via USB can take 8 HOURS! So it's going to be slow but as long as the screen is off, it should charge.
-Kevin
People need to keep the iPad screen off and let it sit. It's going to be slow over USB regardless. I've heard (from Andy Inhakto) that charging via the power adapter takes up to 4 hours....and via USB can take 8 HOURS! So it's going to be slow but as long as the screen is off, it should charge.
-Kevin
With the screen off it also charges fine on my tower (front USB port) XP machine - built in 2005.
-Kevin
-Kevin