And is capable of charging the iPad while under heavy use. The 12W will actually allow the battery to deplete in same scenario.
It's a MacBook charger, and you would also need to buy a USB to Lightning cable. I don't know the exact difference with charge time, but in non-technical terms I can say that it's a helluva lot faster!
I was just going to make a thread asking if this is normal; wondering if mine takes a longer time to charge compared to others.
When it's fully charged, I can see it lasting the entire 10 hours of use that Apple claims. (I've never actually let it go below 70%.)
When when I'm using it while plugged in, it will charge maybe 1% per 45-60 minutes.
The only way I can get it 100% charged is if it's not in use.
Yes, that is the problem with the 12 watt charger. It's just barely enough to charge the battery. The 29 watt charger has plenty of power to charge the iPad, even when in use.
Here's a great article that really shows the benefits of the 29 watt vs 12 watt:
https://www.macstories.net/ios/testing-apples-29w-usb-c-power-adapter-and-ipad-pro-fast-charging/