So I have received a ton of questions regarding how I added Qi to my phone, and its sort of scattered throughout this thread so I decided to edit the OP and lay it out step by step.
Here are the parts I used:
GalaxyS4 charging card: http://www.ebay.ca/itm/331536120289
LG G3 coil combo: http://www.ebay.ca/itm/261756381973
You will need both becase the S4 card does not include NFC, and the G3 card does not include the Qi PCB circuitry.
power down, remove sim, remove battery cover, remove lower speaker module. you can find how this is done here: https://www.ifixit.com/Teardown/OneP...Teardown/26484 (you do NOT need to remove the upper cover nor the battery. just the back cover and lower speaker assembly)
Solder wires to the outside pins:
Route the wires into the battery cavity, replace the speaker. Here is the wiring diagram of a Micro-USB cable. Since the OPO is laying face down, this image would have to be "inserted" into the plug on the OPO then flipped so the narrow part of the plug faces up. The +5 pin ends up on the right like in my photo above.:
Remove the paper from the S4 card, cut out this part. Be sure to take note of which trace leads to the "outside" and "inside" of the coil:
and solder the wires from the micro-USB port to the coresponding pins marked on the S4 PCB (on the right side in this image) +5 & GND. I used a small piece of thin 2-sided tape to stick it to the battery.
Also follow the traces in the PCB for the Qi coil side. On the left side of the PCB I added a red wire to the trace that goes to the outside of the coil, and a black wire to the trace that goes to the inside of the coil:
I then removed the G3 Qi/NFC coil from its paper backing, and cut to seperate the NFC from the Qi traces. I just cut along this gap:
Next just align the POGO pins on the OPO to the NFC pins on the G3 card:
I "accordioned" the NFC traces so that the coil will sit higher / more central on the rear of the phone. Use 2-sided tape to hold it in place.
Then take the leads you soldered to the coil side of the S4 PCB board and match the red to the lead that goes to the outside of the G3 coil.
Carefully stick it all down to the battery. Here is the finished install:
Now just remove the NFC coil from the inside of your back cover. I also removed the sticker from the inside of the styleswap cover (only exists on bamboo - does not exist on the black or white covers). I also sanded down the plastic ledge around the location of the OEM NFC to free up a every tiny bit of available space:
and close everything back up. Mine fit perfectly flush with the bamboo cover:
I have an LG WCP-300 Qi charging puck. It has a rated output of 1000mA. It looks like this:
and I consistently get 850-900mA while charging:
NFC works exactly like stock, the Micro-USB port also works exactly like stock. I can still charge over micro-USB and get the proper 1800mA charge rate while using it.
Any questions just let me know!