when i plug my new retina ipad mini into a usb port it shows charging then not charging?

Not all USB ports are capable of supplying a high enough charge current:

http://support.apple.com/kb/HT1476

Wow, you're not kidding. NONE of the USB ports on my DESKTOP computer are capable of charging my new iPad mini retina. I would have never guessed that would be the case.

Try lowering the brightness of your screen.

No, screen brightness doesn't matter. The USB ports on my computer just don't put out enough current--need 2.1 amps, I'm guessing. The wall adapter works fine to charge my mini. It's just that now I don't have the convenience of plugging into my PC (or anyone else's, probably) to charge. I must use the adapter.

It depends upon the computer. Most USB2 ports only supply the minimum required by the USB2 spec, i.e. 500ma, which is not enough to charge an iPad that has the display turned on. It is enough, however, to charge the iPad, albeit very slowly, when the display is off.

USB 3 ports on Apple computers supply a minimum of 900ma which will charge the iPad with the display on or off, but, again, very slowly if the display is on. Some Apple ports supply more current.

Take a look at this article on the Apple support web site.

mboren,

You haven't told us what computer you are plugging this in to.

A 20 year old computer, or a few years newer then that?

An Acer computer, HP, Apple..... What?

A USB port does not necessarily supply a high current.

It is often only around 500 mA to be shared by all USB devices connected to the USB bus.

Your iPad will be recharged on any USB port, but if only 500 mA are available, the recharging process will be extremely slow!

Try this first - Reset the iPad by holding down on the Sleep and Home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons. (This is equivalent to rebooting your computer.)

The quickest way (and really the only way) to charge your iPad is with the included 10W or 12W (5W on Mini) 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 (5W). When attached to a computer via a standard USB port (2.5W, 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%.

How to Calibrate Your Mac, iPhone, or iPad Battery

http://www.macblend.com/how-to-calibrate-your-mac-iphone-or-ipad-battery/

At this link http://www.tomshardware.com/reviews/galaxy-tab-android-tablet,3014-11.html , tests show that the iPad 2 battery (25 watt-hours) will charge to 90% in 3 hours 1 minute. It will charge to 100% in 4 hours 2 minutes. The new iPad has a larger capacity battery (42 watt-hours), so using the 10W charger will obviously take longer. If you are using your iPad while charging, it will take even longer. It's best to turn your new iPad OFF and charge over night. Also look at The iPad's charging challenge explained http://www.macworld.com/article/1150356/ipadcharging.html

Also, if you have a 3rd generation iPad, look at

Apple: iPad Battery Nothing to Get Charged Up About

http://allthingsd.com/20120327/apple-ipad-battery-nothing-to-get-charged-up-abou t/

Apple Explains New iPad's Continued Charging Beyond 100% Battery Level

http://www.macrumors.com/2012/03/27/apple-explains-new-ipads-continued-charging- beyond-100-battery-level/

New iPad Takes Much Longer to Charge Than iPad 2

http://www.iphonehacks.com/2012/03/new-ipad-takes-much-longer-to-charge-than-ipa d-2.html

Apple Batteries - iPad http://www.apple.com/batteries/ipad.html

iPhone: Hardware troubleshooting (Power/Battery section also applies to iPad)

http://support.apple.com/kb/TS2802

Extend iPad Battery Life (Look at pjl123 comment)

https://discussions.apple.com/thread/3921324?tstart=30

New iPad Slow to Recharge, Barely Charges During Use

http://www.pcworld.com/article/252326/new_ipad_slow_to_recharge_barely_charges_d uring_use.html

iPad: Charging the battery

http://support.apple.com/kb/HT4060

Best Practices for iPad Battery Charging

http://www.ilounge.com/index.php/articles/comments/best-practices-for-ipad-batte ry-charging/

Tips About Charging for New iPad 3

http://goodscool-electronics.blogspot.com/2012/04/tips-about-charging-for-new-ip ad-3.html

How to Save and Prolong the battery life of your new ipad

https://discussions.apple.com/thread/4480944?tstart=0

Prolong battery lifespan for iPad / iPad 2 / iPad 3: charging tips

http://thehowto.wikidot.com/prolong-battery-lifespan-for-ipad

iPhone, iPod, Using the iPad Charger

http://support.apple.com/kb/HT4327

Install and use Battery Doctor HD

http://itunes.apple.com/tw/app/battery-doctor-hd/id459702901?mt=8

To Extend a Device’s Battery Life, Get to Know It Better

http://tinyurl.com/b67c7xz

iPad Battery Replacement

http://www.apple.com/batteries/replacements.html

In rare instances when using the Camera Connection Kit, you may notice that iPad does not charge after using the Camera Connection Kit. Disconnecting and reconnecting the iPad from the charger will resolve this issue.

 Cheers, Tom 🙂

Yeah, checking in the Device Manager, USB Root Hub, Power tab, it looks like the USB ports each receive 500 mA. Per the Apple support page, the iPad mini is demanding higher current (900 mA?) to charge at it's normal, higher rate.

Apple peripheral devices may request more than 500 mA (Milliamps) at 5 V (Volts) from a port to function or to allow for faster charging. Such Apple peripheral devices include:

• Apple MacBook Air SuperDrive (when connected to supported computers)
• Aluminum Wired Keyboard*
• iPod
• iPhone
• iPad

So, if I ignore the warning that my iPad mini retina is "Not Charging," I may be able to slowly charge it with 500 mA at my PC's USB ports. I'll test that.

By the way, I have a fairly new, custom-built (AVA Direct) computer just shy of 3 years old with an ASUS P5K motherboard that has both USB 2 and USB 3 ports.

CZ-1 wrote:

So, if I ignore the warning that my iPad mini retina is "Not Charging," I may be able to slowly charge it with 500 mA at my PC's USB ports. I'll test that.

Yes, it will recharge your iPad, but maybe only a percent increase per 15 to 30 minutes depending on what else is using the USB bus.

Your mileage may vary...

Test is done, and yes, the iPad mini retina DID recharge successfully from the USB port on my PC even though the iPad mini displayed, "Not Charging." 🙂

By the way, I use an app to monitor the battery and recharging. If I leave the app running/open on screen when I put my PC into Sleep mode, the iPad mini continues to recharge until it reaches a "full charge" per the Battery Doctor app. So not only can I charge when the iPad says Not Charging, I can charge with my computer basically off. Ah the irony. 😉

The problem with recharging an iPad on a computer's USB port is that one cannot count on it as it varies too much from one computer to another.

Therefore the good method to recharge an iPad is to use the supplied charger.

My iPad mini retina not charging with Windows 8, (with win7 was ok)

There is a fix. I have used Asus Ai Charger for several years and with several different computers.. It changes the charging rate of a 2.0 USB port. I have never had any harmful effects.

http://event.asus.com/mb/2010/ai_charger/

If you have a computer with a 3.0 USB you are OK.

As indicated a 2.0 port will charge but very slowly, better when the display is off. All USB ports follow the same standards, what varies from computer to computer is if they have 1.0, 2.0 or 3.0 ports and sometimes they have a mix. My Dell has two 2,0 and one 3.0 ports and the 3.0 is "hot" as long as the battery is charged, computer off or on. Along with charhing rate, the USB ports vary in data speed.

Excellent! I tried downloading and installing the ASUS Ai Charger, and it seems to work. Thanks for the tip!

And thanks, ASUS. 🙂

(iPad mini retina 2013, ASUS P7P55D-E motherboard, Windows 7 64-bit)