5857 Views 8 Replies Latest reply: Sep 27, 2010 3:02 PM by Paul141
Some USB ports don't deliver enough juice to charge an iPad. The iPad charger requires 10 V while older iPhone (don't know about the iPhone 4) and all iPod chargers require 5 V which is why you also can't charge the iPad using an iPhone/iPod power adapter but you can charge an iPhone/iPod using an iPad power adapter.
I'd say the USB port you're using on your computer simply doesn't put out enough power. On some computers some ports put out more power than others so swapping USB ports may solve your problem but it may not. You may only be able to effectively charge your iPad using the adapter.
The software linked below works very well. I've tried it on a number of PC's and laptops without a problem. There are some reports of problems on the web so a setting a restore point prior to installation is probably a good idea.
To fully charge from about 0 to 100% takes longer than one hour. The iPad battery is 25 watt-hours and the iPad wall charger puts out 10 watts. Therefore the fastest it could charge is 2 1/2 hours.
Apple made it clear that an external charger would be req for iPad. It charges in less than an hour. Better than an iPhone and it lasts for 10 hrs.
The iPAD does require more power and even if the USB port can deliver that required power, it also depends on what is allowed by USB standards.
I have an acer computer that did not charge the ipad with the cable supplied. I have written about a device called the CSQUID that I got on Amazon that has a special "greenchg" setting to allow it to charge from any PC. The cool thing is that it even charges from my PC when it is in standby so I do not need to install any drivers or open on itunes when all I need to do is charge.
If I want to sync then I simply change the setting to "syncchg" and that allows me to sync data.
Where did you get the 10 Volt from? I never heard of a USB 2.0 bus providing 10V.
The iPad charges on a normal USB connection. It just charges very slow and only when the screen it turned off. The Voltage is always 5 Volt. A normal USB bus supplies only 0.5 Ampere. Some newer computers/mother boards support 1.0 Ampere. The iPad charger supplies 2.1 Ampere. All these are still at 5 Volt.
Compared to the original charger the 1 Ampere output will take twice as long. On a normal USB connection it will take 4 times as long.