eBay Chinese wireless chargers?

[electrolux]

Anyone out there tested one of these cheapo wireless chargers?

BTW: First post after about a year!

http://pages.ebay.com/link/?nav=item.view&id=221937442437&alt=web

[electr_peter]

It is a hit and miss - quality variation is huge, meaning working frequency can be seriously of limit (mismatched Rx/Tx) and efficiency would be very poor. Also, charging current is low and parts of Rx/Tx heats up a bit.

I have bought a similar charger pad and receiver separately. Charger did work with phone's original receiver embedded in case. Separate receiver pad did not show any signs of life no matter what I tried.

[Mephitus]

Coincidentally I just ordered one to test. So I will let you know what I end up with.

[TheSteve]

I have a charger that looks more or less the same that came out of china a few years back. You never know what the insides will look like though. In my case the charger works extremely well. I have a second smaller "puck" style one that charges at a good rate but likes to cycle on and off which is annoying. With a Moto Maxx I've never had any issues of heat, with some other charging pads meant to go inside Samsung phones I experimented with though I saw temps over 80C on some parts - not ideal.

[Mephitus]

Just got mine in. Seems to work just fine. The worst I can say about it so far is that the area that can charge my phone is rather small. Being generous, there's maybe a 1cm diameter zone to mate to the charging coil of my phone, a Samsung Galaxy S6. Which can be a bit annoying since the surface texture has almost no grip to the phone and nothing to grip the surface of the table. I think I will put down a thin layer of silicone or something to stop my phone from falling off when it's set to vibrate. I haven't had a change to test efficiency yet, but the printing on the back cites 5v2a input with a charge potential of 5v1a output. I am kinda curious why the 2 unpopulated IC pads though.

The 2 chips of note are a jellybean LM324 voltage regulator and a ISL78223 "ZVS Full-Bridge PWM Controller". Which makes sense to create the oscillating magnetic field. I will have to hook it up to my scope when I get home too.
http://www.intersil.com/content/dam/Intersil/documents/isl7/isl78223.pdf

The SOT-23 transistors are just some SI2305 and SI2306
http://www.vishay.com/docs/70833/70833.pdf
http://www.vishay.com/docs/70827/70827.pdf

[saturation]

I ran several tests and gave up.  If positioned suboptimally the device either got uncomfortably hot, over 45C or even if not was inefficient even though the device signaled it was charging "well".  The deal breaker was even when I forcibly cooled the device < 35C and optimized position, at charge termination the battery was not as filled compared to a direct USB connection charge.  I monitored charging via in-line hardware volt-ammeter, in-device Android voltmeter and ammeter app, temp sensor apps, physical thermocouple, IR thermometer scan.  At best, the ammeters reported the Qi device pulling 1.5A while the phone was receiving charge current at 0.70 A, and that's with the phone powered off.

[HKJ]

I have played a bit with some: http://lygte-info.dk/review/QI%20A%20look%20at%20UK.html

[nanofrog]

I've a couple (single coil chargers), and they tend to be picky about placement.

You'd do better with a 3 coil charger, as they're much easier on placement (example, located in UK), as well as more forgiving on charging through protective cases.

[saturation]

Very nicely done and detailed.

I have played a bit with some: http://lygte-info.dk/review/QI%20A%20look%20at%20UK.html

[electrolux]

Thank you very much for all the replies, I've been stupendously busy so couldn't thank you before now!

On the whole I think I'd rather avoid them & go for a proper brand.