IPAD 2 Won't Charge on USB port on my laptop, my desktop Mac but will charge via the wall plug

The wall adapter is rated for 100 to 240 v (which I think covers every country), so you should just need an adapter for it and not a convertor.

A lot of computers (especially older ones) generally do not provide enough power to their USB ports to charge the iPad at a sufficient rate - it may still be charging slowly, and should be a bit quicker if the iPad's screen is off (if you leave it for a while and then disconnect it from your computer you may find that it's battery percentage has gone up). The wall charger is usually the most efficient way to charge the iPad.

It's a little confusing, yes. Although it says Not Charging when you plug it into some USB ports, it should fill up when the iPad is sleeping.

Macworld Magazine wrote a great article about iPad power requirements:

http://www.macworld.com/article/150356/2010/04/ipadcharging.html

It explains a lot.

King_Penguin wrote:

The wall adapter is rated for 100 to 240 v (which I think covers every country), so you should just need an adapter for it and not a convertor.

And for future reference, cara_legault, when in doubt about a device, always look closely at its power supply because electrical ratings should be stated on it. I just looked at my iPad adapter and "100-240V" is printed on it. Although Apple needs to print it in letters that are easier to read!

For better future reference, you should be aware that the voltage means nothing when it comes to charging power. All that that is telling you is that the Power Adapter will work across that voltage range, i.e., you don't need a transformer to plug it into the outlet (although you may need different plugs, which is a separate topic).

What matters is the amperage (A) and the power in watts (W). The Power Adapter puts out 2 A @ 5 VDC (volts DC), which means it's producing 10 watts of power. It will output that across the entire voltage range.

A high-power USB port on a PC will put out 0.5A @ 5VDC, or 2.5 W. Be aware that not all of the ports on any given PC are likely to be putting out even that much power, at may well be putting out less than half as much. That's why you'll often see the "Not Charging" when plugged into a USB port, especially on Windoze laptops, and why it will charge very slowly even when it works.

FYI, the charger which is sold with the iPhone looks identical, is called the same thing, but only puts out 1A. It will work on the iPad but will charge more slowly. By that same token, the iPad charger will charge an iPhone just fine, it will just charge faster.

The quickest way to charge your iPad is with the included 10W USB Power Adapter. iPad will also charge, although more slowly, when attached to a computer with a high-power USB port (many recent Mac computers) or with an iPhone Power Adapter. When attached to a computer via a standard USB port (most PCs or older Mac computers) iPad will charge very slowly (but iPad indicates not charging). Make sure your computer is on while charging iPad via USB. If iPad is connected to a computer that’s turned off or is in sleep or standby mode, the iPad battery will continue to drain.

Apple recommends that once a month you let the iPad fully discharge & then recharge to 100%.

At this link http://www.tomshardware.com/reviews/galaxy-tab-android-tablet,3014-11.html , tests show that the iPad 2 battery will charge to 90% in 3 hours 1 minute. It will charge to 100% in 4 hours 2 minutes.

 Cheers, Tom 😉