Recently I noticed that my iPad was not charging as quickly as it used to. Only a month or so ago I was impressed at how my iPad's battery would easily charge up to the 80% range in a couple short hours, but more recently the same charge time would produce a meager 10% if I was lucky. It was infuriating, and the only thing more infuriating was that I couldn't figure out why. After doing a bit of research this is what I discovered.
Being aware that the iPad requires more power to charge (10 watts), I was sure that I was using the right adapter, the one that came in the box with my iPad. However, I became increasingly aware that I had various iOS power adapters strewn all over the house which looked identical to what I assumed was the iPad charger as well as a few compact adapters, one of which came with my iPhone 4, and others that I just seem to have accumulated from goodness knows where. I suddenly realised that I could have easily picked up the wrong charger and mistaken it for the iPad one. The problem was how to decipher one adapter from the next.
The compact Apple Power USB Adapter, the one that comes with an iPhone 4 or 3GS, is a 5 watt adapter, but it doesn't actually say that anywhere on it. However, it does indicate that the output is 5 volts at 1.1 amps (5V 1A), which means 5 watts (I realised this after a bit of learning about electricity). This adapter will charge your iPad, but at a much slower rate because it only has an output of 5 watts. According to Apple's website, this adapter is compatible with all iPhones and iPod touches as well as what appears to be all previous iPods too, but not the iPad.
The more chunky adapter that comes with the iPad is a 10 watt adapter. Thankfully, this adapter is labelled as a 10W USB Power Adapter (see gallery). Its output is 5 volts at 2.1 amps (5.1V 2.1A) which means 10 watts. Obviously, this is the adapter that will charge your iPad correctly, and as a result, the fastest.
However, there is a third adapter that looks identical to the iPad adapter, but it will not charge your iPad at 10 watts. Apple doesn't sell these anymore, but you may have a few around your house if you ever had a wall charger for previous generation iPods and iPhones. This is where I went wrong and couldn't figure out why my iPad wasn't charging correctly, I was using one of these adapters mistaking it for the iPad one. Fortunately these adapters are labelled iPod USB Power Adapter (see gallery).
I finally located my iPad adapter attached to a travel adapter I'd thrown in a drawer after recently being abroad. And I'm pleased to say my iPad is charging normally once again!
Don't make the same mistake I did, make sure that your iPad is being charged by the correct 10 watt power adapter that came in the box with your iPad or a third party iPad compatible charging accessory.For further information on charging your iPad, and getting the most out of your iPad's battery, check out this support page at Apple's website.