iPad Pro takes so much time to charge! Any tips?

Compared to my iPad Air 2, which would generally take between 2-3 hours to charge from 10-15% to 100%, my newish iPad Pro seems to take a very long time to charge using the same percentages. I began charging about 4 ½ hours ago and have gone from 13% to 42%.

I am user the actual wall adapter that came with the Air 2 and the USB to Lightening cable that is Apple certified made by iOrange-E , with the nylon-wrapped cord, as every Apple cable would twist and become useless. I have been using the same charger and cord for months with my Air 2 with no problems. Is there a difference between the charge adapter for the Pro and the Air 2? Has anyone else noticed a difference? This is making me crazy! I do not sleep long enough at night to fully charge this iPad!

Any help or solution?

On a positive note: I watched my first movie on this monster last week and was digging in my pack to find my beats earbuds but accidentally started the film and I had my first taste of four speaker. No need at all, unless you're in public, for other speakers, headphones, earbuds, etc. The film had every flavor of sound recording and massaging available. And it looked fantastic, as well.

Someone wrote that there should have been a "ProOS" written for this device. It clearly has more power underneath the hood for some more exotic features.

SIgh. Made it to 43%. This isn't acceptable. I hope that you guys or girls can come up with a simple fix for this... Because sending the machine back to Apple isn't the solution that I'm looking for!

Thanks,

Clinton