Guys, I'm just going to do a cut & paste from my Reddit post here. Is the device really slow to charge for you all? These are my results from just an hour ago...
----
I'll add my input to this as I received my K1 a few days ago and as I type this, it is going through its first full charge from 4% to 100% right now.
My K1 has Lollipop 5.1.1 on it and I previously did notice it charging quite slowly from 80-100% using my 21W 2.4A Apple iPad charger, which I recently sold with my iPad 3.
So yesterday I took delivery of this charger from Amazon UK. Another 21W high output charger. http://www.amazon.co.uk/gp/product/B019H0K1CK
Before going to sleep last night at midnight I set the Shield to charge. It is now 07:33 (7.5hrs have passed) in the morning and having just woken up, the shield is at 98%. Something doesn't make sense.
I charge a lot of things in this house via USB and this is the first time I have come across such a slow charging device. It is the K1's FIRST full charge I should add. The same USB cable I use to charge my Note4 without issues as well as my Kindle.
Might just order one of these USB Multimeter's to see what is going on. http://www.amazon.co.uk/dp/B00Q2HWLYS
Read about the battery drain issue. Might explain it.