iPad 2 not charging when connected to PC

The iPad has a much bigger battery, and needs more current than the iPhone to charge it. To take an extreme example, you wouldn't expect to charge a car battery from a USB port. :-)

>>The iPad has a much bigger battery, and needs more current than the iPhone to charge it. <<

ok, let's not be foolish here. I have an Android phone with a 3700mA battery while The iPad is a 3500mA.

My laptop's USB charges the Bigger Android battery just fine.

Folks, let's be honest here.. it's not the battery or greatness of the Ipad. There's technically no reason a PC USB port can't charge on just as easily as a Mac USB port. They're no doubt made by the same hardware companies in China for crying out loud. They HAVE to provide the same power specs if they are USB2.0 because that's an industry determined specification. You cannot make one, one way, and one USB2.0 port the other providing less power. They could not be called USB2.0.. .legally.

Kind of like if you say your monitor is 1080p and it's actually 1070 pixels veritcally... well that's a flat out lie. It's not 1080p. USB2.0 is far far more stringent on it's specs because it's not just a method of transfering data its' a method of sending electricy to devices. Like an iPad.

There is simply an "Apple" override coded into the iPad, that, for whatever reason, determines that if it's plugged into a PC Laptop, Do Not Charge correctly.

Why? No idea.

ekholbrook, that is a bit cynical, don't you think? Not only that but your technical information is incomplete and overly simplistic. USB 2.0 is not USB 2.0. There are different charging standards.

The short version:

Regular USB 1.x and 2.0

Current available without negotiation: 100mA

Max current available if the device and the host computer negotiate it: 500mA

For USB 3.0 those numbers are 150mA and 900mA respectively.

USB Charging Ports (2007 spec)

These come in two varieties: downstream charging port (i.e., one that can also act as a data connection), and dedicated charging ports. A USB device can know it is connected to a dedicated charging port by seeing that the D+ and D- lines are shorted. The current limit for a USB charging port will depend on whether there is a high-speed data transfer currently in progress (for a downstream charging port), as well as on the design of the particular connector. Generally the limit is 1500mA.

Non-standard ports

Apple's iPhone charger provides 1000mA. It tells an iPhone that is is allowed to draw this much current by placing special voltages on the D+ and D- lines. When an iPhone is plugged into a regular host computer, it will negotiate with the computer and draw up to 500mA if that is available.

Apple's iPad charger provides an astounding 2100mA of current (10W of power).

Source: http://en.wikipedia.org/wiki/USB#Power

Analysis

The iPad will charge on a variety of currents. Obviously more current will result in faster charging. As has been mentioned above in this thread, it will even charge on the 500mA of current provided by a regular USB port, as long as the massive bright screen is not on. Try it. Plug it in, put it to sleep, and look again in the morning. It will charge. (Actually, it may even be charging slowly with the screen on, but not fast enough to engage the "Charging" indication. I have not tested this.)

The iPad will charge faster on 1A of current, even with the screen on. This is why it works fine with the small iPhone charger and with USB ports that will provide 900mA of current (that would be USB 3.0 ports and USB 2.0 ports that are providing a greater-than-standard amount of current.)

The iPad will charge fastest, of course, with its own dedicated 2.1A charger. As far as I know, neither PCs nor Macs provide this much power.

I will repeat that you use tweaks like the ASUS patch at your own risk. If your particular motherboard /chipset was not designed to provide that much current you may well burn out something prematurely. Not to mention destabilizing your Windows installation with what I found to be a flaky piece of software (good luck with the uninstall!). Besides, slower charging, all else being equal, is better for the long-term life of the battery anyway.

I think the reason the iPad charges at 1A (or probably 900mA) with newer Macs (it does not work with older Macs) and not with most PCs is simply that Macs implemented USB 3.0 sooner than most PCs did. (It may also be that the Macs' USB ports were designed to provide a greater-than-spec amount of current.) But I don't think it's a conspiracy.

I can't explain why your Android phone charges differently, but it is possible that its charging circuitry is designed to operate at a lower current. But you can't get something for nothing; when plugged into a standard USB port it's likely charging quite slowly, just like the iPad when plugged into a standard USB port with the screen turned off.

>>ekholbrook, that is a bit cynical, don't you think?<<

It is totally cynical. I have never had a problem charging anything on a PC. I have 3 removable, USB powered... 500 gig drives, an iphone AND that android phone on my laptop. All charging and running.

Yet it can't charge an iPad with a smaller battery?

Please...

I just used this website actually today and it worked for me thanks

Absolute not true. Want proof? I get the "Not charging" when I plug my iPad2 into a USB port on my late-2011 iMac.

I was having the same issue on ipad1 and it said "not charging:. So i tried that ASUS patch and now it's charging fine. thanks so much!!

btw I plugged it into a HP xw8200 Workstation PC.

Not an Asus or a laptop. Works fine.

Thanks for your fix ! It worked for my HP G72 Laptop!

WOOOOOOOOW, awesome.. worked for Gateway Laptop

Thanks

Thanx for this buddy.You saved my day.Much appreciated!.

The ASUS patch works for charging my iPad 2 on my old Lenovo T60 (T stands for truck)<:) Don't know what the charging current is, but don't care as long as the % is going up!

The Asus patch worked great on an HP-Compaq DC5700S running XP. Just install and restart.

I can't believe we have to go through a separate "magic patch" to fix that problem. Patch on witch we have no control and certainly no service at all. This is unbelievable !

I was charging fine my Ipdad 2 on my PC without any trouble for a year now. Last week I uploaded my Ipad to the laster version of IOS and since then I cannot charge my Ipad through my computer USB anymore. This is absolutely not a hardware problem, it is apple who limits his products not to work in certain situation.

Why is my Ipad charging well with the charger or on my MacMini but since the update it doesn't charge on my PC.

Can someone from apple answer me why or can I get lost since I didn't bought there very expensive care plan ?

Conspiracy theories abound!!

Seriously people, this is not about Apple. It's about you. If you plug in too many USB devices to the same port set then something has to give. This is about Wattage and basic physics, not about Apple holding out on you.

I posted 2 months ago about this: It happens on my iMac 21". You know.. the one made by Apple? As soon as I unplugged one of the other 'large charge' items the iPad charges just fine. Verify your power sources and your power sinks. Betcha good money that's your problem.

Thanks for the advice but my problem has nothing to do with physics. My mother board didn't stop to deliver the 5V needed nor did it stop to supply the same amount of ampere has it did before I updated my Ipad.

I don't overload my chip and except my mouse and keyboard I don't charge my computer's USB ports (they are not on the same USB chip anyway).

Nothing has changed except that once upgraded the unit simply stopped to charge. I believe it has been done to deal with the battery of the brand new Ipad 3.

I'm complaining about updates that deliberately create new problems.

Your problem on your IMac 21 is just the result of the way USB works. Mine has to do with the way the Ipad has been programmed to work...