As you may know, almost all of Samsung’s flagship smartphones since Galaxy S3 are equipped with a wireless charging capabilities. They support the Wireless Qi charging standard, and you must purchase a separate back cover for the phone. For the galaxy S4, you need to have the wireless charging back cover and wireless charging pad. The official kit with set you back around USD100 in total, and it has limitation that it cannot be used together with the S4’s flip cover
The good things in having a popular phone is that you can never be out of options for third party accessories. Sites like dealextreme and aliexpress provide plenty of cheap selections, although most of them are chinese knockoff or replica. Both sites offer free shipping to Indonesia via airmail. It may take 2 to 4 weeks for your package to arrive.
I got this charging pad from dealextreme for USD30. I choose this one because it uses micro USB port for power source, so I can use my idling blackberry and nokia chargers.
As for charging receiver, there are so many options, so I decided to get a couple of them for testing, since they were quite cheap. I get the Metrans patch from dealextreme, and also these two nondescript ones from aliexpress. The Metrans from dx and the white one from aliexpress are pcb type patches, and the other one is a coil type receiver. These are the one that I got from aliexpress:
In short, all three of the charging receivers work, for charging that is. It also happens to block nfc connection. Crap. After searching around, I found out that the interference might be caused by aluminum pad or sticker that is put around the receiver patch. So I took it off of the 2 of the 3 patches that I have.
The last patch has a coil type receiver, so it is impossible to use without the cover sticker.
The white one only has sticker on one side, so it will be totally naked when you remove the sticker, and the pcb patch will have a direct contact with your battery. The black one from dx has sticker on both sides, and I decided to remove only one of them, so it still has an aluminum sticker that sits between the battery and the patch.
To install, all you need to do is to align the contact, and the patch will sit perfectly on top of the battery.
And now, NFC works! Tested with Sony SmartTag. I also checked wifi and GPS, and everything is working normally.
So, in summary:
Nondescript #1 from aliexpress
Out of the box, this one works but block NFC. You can’t peel the sticker since this one is a coil type patch, I don’t recommend exposing your phone battery to a bare coil of wire. It’s bulky and I can never get nfc work with it, so out of the question
Nondescript #2 from aliexpress
Just like the other two, this one also works, and just like the others, it blocks nfc out of the box. You can make nfc work if you take out the sticker. Sans sticker, the white nondescript patch is the thinnest of the three, and it fit very well under the S4 back cover. The problem is, just a couple of minutes of charging turn your phone scorching hot, since nothing prevent heat from being transmitted from the pcb to the battery. I did not finish the test to avoid ruining my phone, so I don’t know whether the charging it can correctly stop charging after 98%
Metrans patch from dealextreme
NFC is also no go with the Metrans out of the box. I took out the sticker on the side that faces the back cover, and voila! nfc works! The Metrans patch from dx is not as thin as the white one, but I still managed to tuck it inside the phone using the standard back cover. It will have bulge it some places, and you may have difficulty in putting on some cases. My red Spigen Slim Armor barely fits. It has some sort of heat dissipation layer that sits between the patch and the phone’s battery, so your phone won’t get unreasonably hot during charging. The patch also correctly stopped charging after reaching 98% so it won’t overcharge.
So now, summary:
Can you get cheap wireless charging on S4?
Depends. What I have now cost less than USD60, so that’s about USD40 cheaper than the official wireless charging kit.
Does it work?
Sort of. Charging your phone with wireless patch will take about 2 times longer than using standard charger. I use wireless charging to lightly top up my battery at the office so that it can get through the end of the day. For charging your S4 fully, I still recommend using the old fashion wall wart.