S4 Mini doesn't have the wireless charging chip/card in the back by default...
For S4 and others, you could add in the capability by adding a Qi card like this: http://www.kogan.com/au/buy/qi-wirel...ard-galaxy-s4/
If you look it has a contact strip coming off it (Second photo) that connects to the phone via 2 pins in the back of the phone, as far as I am being told by "Kogan" (A local Gadget Co in my Country) S4 Mini does not support the Qi card as when I pull the back off my phone, I dont see those 2 pins like the normal S4? So no way to charge the battery? I wonder if it could be modded to contact directly to the battery??? but I guess the phone would have to control where the current goes so that wouldn't work.
I wonder if that would work though, mod teh Qi card so it connects to the battery pins so that when you place your S4 mini with Qi on the mat, power is drawn from the Qi side and not the battery thus, saving you battery power rather than charging it? Thinking about it, this might a pretty cool device to put into full scale production???
Samsung Galaxy S4 mini: running...
ROM: JB-4.3.1: CM.10.2
Google Nexus 7: running...
ROM: KK-4.4: CM.11 Nightlies
Retired, hall of fame:
Google Nexus 4
Samsung Galaxy S2