Amazon Selling Fake Amazon USB Chargers

[calzap]

I wanted yet another USB charger and was happy with the one that came with my Amazon Kindle.  It performed well and had all the important agency stamps (UL, FCC, etc.) on it.  So, I go to Amazon to buy an identical one, find it at a reasonable price via one of their partners, and buy it.  Didn't realize until later that the partner was in China.

As soon as it arrived, I saw it was a fake.  It didn't have the agency stamps, even though they were pictured in the seller's ad, and the plastic at the prong-end appears different from the genuine article.  See the pics.  No way would I trust my equipment to this thing nor would I trust it not to start a fire or give me a shock. 

Emailed Amazon and got a stock reply back.  If it gets kicked up a notch in their organization, which is iffy, I may hear more.   I may unzip both, which will take a lot of Dremel-work, to have a look at their innards.  Anyone want to bet they'll be identical?  Even if the layout and components look the same, component quality will probably differ.  I'll wait a bit to see if there is anything more from Amazon or the seller.

Mike in California

[free_electron]

yep fake

[TheBay]

The irony!

[nitro2k01]

Unless you paid a fortune for it (ha!) and desperately want to return it for a refund, open it up and have a look inside and maybe take some photos. It should probably come apart easily if you whack the prongs with a hammer, for example. (I'm not suggesting it's not fake. It clearly is. But it would still be interesting to see exactly how crap it is.)

[dannyf]

Before you open it up, do some tests to see if those parts have comparable performance.

And ask the experts here how they think the two will perform differently,

[nukie]

Is it worth the time profiling something that will get cleaned up sooner or later? I think time is better spent comparing genuine AC adapters from different types of products. We all already know how dangerous these fake are I don't think we need anymore internal pics of these rubbish.

I think you will benefit more by making a youtube video of you using a hammer smashing these fake Amazon chargers and prepare for hot responses.

[nitro2k01]

Is it worth the time profiling something that will get cleaned up sooner or later? I think time is better spent comparing genuine AC adapters from different types of products. We all already know how dangerous these fake are I don't think we need anymore internal pics of these rubbish.

Comparing genuine chargers would definitely be useful, but requires an extra effort. You would have to destroy something you might otherwise use. (Or pay for spares that you're just going to use for testing.) The idea here is that he's not going to use the charger anyway, so he might as well crack it open.

[amyk]

Is it worth the time profiling something that will get cleaned up sooner or later? I think time is better spent comparing genuine AC adapters from different types of products. We all already know how dangerous these fake are I don't think we need anymore internal pics of these rubbish.

Yes because they are not all equal and some can be a lot better than others. At the least, do a hi-pot test.

"aifeng" = romanisation of "iPhone" in Chinese. Probably was meant to be stamped on an iPhone charger...

[calzap]

OK.  I will open both for a side by side comparison.  Seller refunded my money and declined to pay shipping back to China ... no surprise.  Would be interesting to see messages between Amazon and the seller.

 First though I will do some tests.  What I've done so far is the no-load voltage (4.91 for the real; 5.30 for the fake).  Also checked voltage from positive and negative output of each to earth ground (zero in all cases).  Next, will use BK Precision load to check voltage drop by running up the current draw in 0.1 A steps.  Will also look for noise with the scope.  I don't have a differential probe, so I'll run them from my isolation transformer (if I can find it).  Just because there is no ground potential with no load doesn't mean it won't appear when the load is cranked-up.  Alternative is to check potential to earth ground at each step, which would probably be a good idea anyway.  Should be able to do the testing later today; may not do tear-down until the weekend.  Will try prying first, then go for the Dremel.  Hammering tends to get overdone in my hands.

Mike in California

[nukie]

Yes because they are not all equal and some can be a lot better than others. At the least, do a hi-pot test.

"aifeng" = romanisation of "iPhone" in Chinese. Probably was meant to be stamped on an iPhone charger...

Yes I know there are good quality generic ac adapters available, what I meant was these products stamped with various name brand illegally, supply are not constant and stable. This week you might get grade A, next week when certain components are out they will change the design to fit whatever low cost component they could source,  hence you get random quality all the time.

I rather people spend time reviewing and investigate products that are made to stay with assured quality so it will be helpful for buyers.

It's nice to look into how those dangerous ac adapters cut cost but time is better spent looking at a product that is designed correctly it would be higher educational purposes.

[dannyf]

First though I will do some tests.

Well thought out.

I look forward to seeing your test results. Thanks.

[calzap]

Here are the first test results.  I earlier stated that the voltage from positive or negative of either device to earth ground was zero volts; DC should be appended.  Yup, forgot to set the DMM (Agilent U1241) to AC. 

Load testing was done with a BK 8540, and voltage readings are from the BK.  The real one has a stated capacity of 0.85 A; the fake has a stated capacity of 1 A. Each was tested within the range of its stated capacity.  See the pic below for the results.

The fake gave up at one half of its labeled capacity.  And no, it didn't die; as soon as, the load was lowered back to 0.5 A or less, it provided the same output as previously.  A little surprised at the ~10% drop by the real one.  In my experience, full-size SMPS-type wall warts usually maintain voltage better than that throughout their power range.  Guess there is a reason for the larger caps and inductors in them.

To check AC leakage to earth ground, I initially used a 2000 ohm, 10 watt wire-wound resistor from either the positive or negative output to ground and measured AC voltage drop across it with the Agilent DMM.  When it became clear that currents would be in the mA range or less, I used a 220 ohm (measured at 218.4 ohms with the Agilent), 1 watt metal film resistor.

The mVAC drop was divided by 218.4 and multiplied by 1000 to get uA.  As can be seen in the table, the fake had higher leakage to ground than the real one, but neither could be considered dangerous.  For both devices, leakage to ground was similar for their respective positive or negative outputs.  I also checked frequency of  leakage with the Agilent and was surprised at the results because I was expecting 60 Hz.  For the fake, the leakage frequency was in the kHz range and varied with the load put on it.  For the real one,  frequency fluctuated from zero to 10 Hz (not kHz) at each load setting.

VDC across the resistor was checked with the Agilent and was zero for either pole of either device with any load setting.   

Before I open the devices, I want to check between outputs and outputs to ground for noise and ripple with the scope.  Hope to get to it soon.

Mike in California

[dannyf]

The fake one doesn't seem to be that bad. Maybe it will win on its value proposition,

[EvilGeniusSkis]

Is it worth the time profiling something that will get cleaned up sooner or later? I think time is better spent comparing genuine AC adapters from different types of products. We all already know how dangerous these fake are I don't think we need anymore internal pics of these rubbish.

Yes because they are not all equal and some can be a lot better than others. At the least, do a hi-pot test.

"aifeng" = romanisation of "iPhone" in Chinese. Probably was meant to be stamped on an iPhone charger...

what does hi-pot mean?

[nitro2k01]

what does hi-pot mean?

High potential. ie a high voltage isolation test between the primary and secondary sides.

[EvilGeniusSkis]

so thats what those "hi-pot ok" stickers mean