[T-Mobile Samsung Galaxy S 4] ncc1701k:
Alright man, I don't want to start a flame war, so I'll try to keep it civil.

I can see that you are quite technologically competent as well, I respect that, I like inquisitive people who go out of their way to discover hard-to-find facts, that's why I started this post in the first place. However, I do ask you to go back and closely read my original comments and not be so quick to judgement, as I believe you misunderstood several points that I was trying to make.

1. Going back to my first post, and take a look at the pictures I attached. I hooked up a battery pack of 4x AAA battery to the left pair (smaller pair) of pins, and the phone indicated that "the phone is now charging wirelessly". This is pretty much proof that this pair of pins can be used for wireless charging. So what you said in your point 3

is incorrect. I can understand your reasoning based on the similarity with the Note 2, but it's simply not the case here.

Now, to also address your point that you think the right pair (the larger pins) are for wireless charging, I would also have to disagree as well. I measured the resistance with a voltmeter and got nothing, which is the same result for the NFC pins on the note 2. It's merely an antenna, so the circuit is not live. I'm not an electrical engineer so I'm not sure why NFC antenna circuits don't register resistance, but that's the case with Note 2 and (supposedly) S4. I even tried my DC power supply on the pins, nothing happened.

In comparison, the left pair of pins registered about 200mOhm in reverse polarity and off the chart resistance on the right polarity, which is the same result with the S3's wireless charging pins (unfortunately it's disabled on the note 2, so I don't have a second data point there).

I don't know if you actually have a S4 on hand to test this, but if you do and happen to have a voltmeter handy, please by all means conduct the test and see for yourself.

2). Going forward a little bit to my later post about the S4's cover of "possibly designed to have NFC", I did acknowledge S4's NFC is on the battery. Everybody knows that, we don't have to argue there. However, this is might be a semantic misunderstanding on your part. I was trying to point out that the back cover was originally designed to house the NFC chip. It may be a design relic, change of mind (moving to a new NFC standard mid-design phase as you mentioned), or simply just options for different geographies, I don't quite know, that's why I shrugged. I was not trying to suggest that any S4 in production actually have back cover NFC instead of battery NFC.

Now, please try to understand that this is just my hypothesis and try to approach it in a more constructive way. Based on my observation and testing with a voltmeter and a DC power source, this would be the most logical hypothesis.

For the two links that I presented in the previous post as a backup to my claim, I do admit the back cover one is a weak piece of evidence. The seller may very well doesn't know what he's talking about, I concede that point. However, in this picture, these are clearly NFC antenna designed for the S4, and would seem to fit just right on the recessed part on the stock back cover

http://wenfengsheng2012.en.made-in-...ry-Cover-NFC-Candy-Color-Fruit-Color-NFC.html

http://images.anandtech.com/doci/6914/SGS4-8042.jpg

3) Finally, I would like to show a picture that's bound to confuse both of us

http://www.phonearena.com/news/Sams...g-back-cover-and-dock-images-leak-out_id41305

This is the leaked QI wireless charging capable back cover for the S4. As you can see it has connections for all 4 pins for some reason. However, I really really doubt that all 4 are for power, since it just would not make sense to have two pairs of inputs when all previous Samsung models made do with one pair of pins for power input.

For the fun part, I would like to propose a reason why (feel free to shut me down, but please be gentle)

It's known that a QI coil placed near the battery would affect NFC performance. It's an known issue for the S3 touchstone modders. So from the look of it, the QI coil on the backcover in the leaked image is just directly on top the the battery NFC, which is not good news for NFC performance. So Samsung tried to mitigate the problem by having a second pair of NFC antenna on top the SIM card slot to augment the original NFC antenna obstructed by the wireless charging.

So that's my (slightly updated) theory. Again, feel free to offer your opinion otherwise. But please remember that none of us have that backcover on hand, so we cannot definitively prove anything just yet. So you can disagree with me, but please don't say that I'm spreading false information.