--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Transmitters (TX): Samsung OEM, Powerqi T-100 (uk seller) and a newer generic Chinese with usb.
So they all behave the same. The charging or trickle temperatures, charge rate and current consumed are all defined by the receiver. The pads
don't switch off at all. Once the RX/TX coils overlap then the pads come on and stay on. The only difference is the sensitivity, charge area, induction distance and features such as beeping and lights.
- The OEM is by far the best quality, but then costs twice the price. It has the largest contact area and induction distance. It's far less fussy where you place the RX and penetrates deeper into cases etc. I'm assuming it uses a larger TX coil than the others. It has a dished matt surface which tends to center the phone. Colour changing charge led and no sounder.
- The Powerqi T-100 has the second best penetration, tested on a Note 2 with a massive Otterbox defender case, went through 3 layers of plastic. As its flat it helps with positioning to overlap the RX/TX for offset positions. Very glossy surface that I found didn't take much for the phone to move and produce a fairly loud beep from the two tone charge led.
- Generic Chinese usb, rubberised surface good for grip. Poor case penetration compared to the others, though it works fine for direct contact. Contact area about the same as the Powerqi. Power led and separate charge led and low volume buzzer. Not bad quality really and the cheapest (£14), no power supply and no CE marks.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Receivers (RX): Samsung OEM, ‘thin’ pcb (solid coil and flexi) and generic Chinese with mc-power internals.
Not all receivers are created equal it seems. I've tested repeatedly using different positions/orientations to try and force inconsistencies. Didn't find anything significant the effected current consumption or temperature. Using the Battery Monitor Widget and Battery Widget Reborn. All temperatures were at a 22C ambient reference level. All wattage measured at the mains side with the same 2A usb power supply and cable. Clock dock not used. All receivers produced a maximum charging current, limited by the phone no doubt, of around 630-680mA.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Again OEM is the best quality as you'd expect for the price. It's a little heavy and very solid. Adds quite a bit of rigidity to the phone. Just about fits inside my SGP Neo Hybrid case and SGP Crumena leather pouch. Charge temps are the lowest by a long way (on any of the pads). You can tell straight away it going to be cooler by the power consumed.
5W on full charge dropping to
1W at trickle. Temps at full charge were
33C dropping to
30C at trickle.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Tried two versions of the ‘thin’ pcb RX. Flexi from a UK supplier and a solid coil for half the price from eBay Hong Kong. Other than the coil/shield they are the same unit, same pcb foils etc. Both pretty slim once foils removed, 0.51mm & 0.57mm across the coils. Ignoring the pcb height as it sits down in the micro-sd slot area. Both fit without significant bulges. They behaved exactly the same in use, though the solid coil area is smaller it doesn't appear to effect positioning. NFC works on both.
There’s something odd with these receivers, they produce the same charge rate (~2hrs from 60% to 100%) but use a
lot more power than the others tested and produce far higher temps.
8W to 9W on full charge dropping to
3W at trickle. Temps at full charge between
43C dropping to
38.8C at trickle.Tried several positions on different occasions, but typically around 42C during charging, 38C trickle
Speculation: As the coil & shielding material is different between the two versions I have, yet they perform the same. And that the solid coil version has a similar coil/shield arrangement to the generic receiver RX (below), with similar charge rates. I'm suggesting that 'all' the extra power consumed is simply being generated as heat by the pcb and accumulating in the phone, hence the higher temperatures.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Generic Chinese, no markings. Stripped off foil as per thin coils. The highest point is 1.1mm and the pcb sits where it will produce a slight bulge. Not massive but it’s there. Performed similarly to the OEM, same charge rate, slightly higher temps and a little more power used, but more than acceptable.
6W on full charge dropping down to
1.5W at trickle. Temps at full charge were
35.2C dropping to
31.4C at trickle. Again NFC tags are detected.
I will add that I also have a 'Metrans' RX in a Note II that uses similar levels of power and produces comparable charging temps.
