Amazon Selling Fake Amazon USB Chargers - Page 1
Forum section: electronics / general

author: calzap
author_rank: Frequent Contributor
timestamp: November 11, 2014, 08:53:08 pm
content: 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

author: free_electron
author_rank: Super Contributor
timestamp: November 11, 2014, 09:00:06 pm
content: yep fake

author: TheBay
author_rank: Unknown
timestamp: November 11, 2014, 10:45:06 pm
content: The irony!

author: nitro2k01
author_rank: Frequent Contributor
timestamp: November 12, 2014, 12:01:04 pm
content: 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.)

author: dannyf
author_rank: Super Contributor
timestamp: November 12, 2014, 12:07:16 pm
content: 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,

author: nukie
author_rank: Frequent Contributor
timestamp: November 12, 2014, 12:58:00 pm
content: 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.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: November 12, 2014, 01:59:44 pm
content: Quote from: nukie on November 12, 2014, 12:58:00 pmComparing 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.

author: amyk
author_rank: Super Contributor
timestamp: November 12, 2014, 03:29:32 pm
content: Quote from: nukie on November 12, 2014, 12:58:00 pmYes 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...

author: calzap
author_rank: Frequent Contributor
timestamp: November 12, 2014, 03:58:27 pm
content: 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

author: nukie
author_rank: Frequent Contributor
timestamp: November 13, 2014, 01:40:06 pm
content: Quote from: amyk on November 12, 2014, 03:29:32 pm

author: dannyf
author_rank: Super Contributor
timestamp: November 13, 2014, 04:17:03 pm
content: QuoteWell thought out.I look forward to seeing your test results. Thanks.

author: calzap
author_rank: Frequent Contributor
timestamp: November 16, 2014, 07:30:40 pm
content: 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

author: dannyf
author_rank: Super Contributor
timestamp: November 17, 2014, 11:59:17 pm
content: The fake one doesn't seem to be that bad. Maybe it will win on its value proposition,

author: EvilGeniusSkis
author_rank: Regular Contributor
timestamp: November 23, 2014, 01:46:52 pm
content: Quote from: amyk on November 12, 2014, 03:29:32 pmwhat does hi-pot mean?

author: nitro2k01
author_rank: Frequent Contributor
timestamp: November 23, 2014, 01:54:54 pm
content: Quote from: EvilGeniusSkis on November 23, 2014, 01:46:52 pmHigh potential. ie a high voltage isolation test between the primary and secondary sides.

author: EvilGeniusSkis
author_rank: Regular Contributor
timestamp: November 23, 2014, 03:59:58 pm
content: so thats what those "hi-pot ok" stickers mean

author: calzap
author_rank: Frequent Contributor
timestamp: July 25, 2025, 03:44:37 pm
content: Recently stumbled on the fake Amazon charger while doing some cleanup. About to toss it when I remembered this old thread. I compared it with a genuine Amazon charger. It stopped producing output at about ½ it’s labeled capacity. Leakage to ground wasn’t bad, about 1/3 mA, but more than the genuine charger.So, it was Dremeled open, and the results are the pics below. Doesn’t look like much (any?) input protection … maybe a TVS or zener diode. Is the black DIP device with 4 pins next to the transformer an opto-isolator? Like most of the components, the DIP component is unlabeled. Are the Chengx electrolytics decent quality? Not a brand I would buy. Comments?Mike

author: Gyro
author_rank: Super Contributor
timestamp: July 27, 2025, 07:32:09 pm
content: Quote from: calzap on July 25, 2025, 03:44:37 pm- Pah, who needs a safe isolation clearance anyway (R3 to secondary)- I wonder if C5 is Y2 rated (it isn't)- Transformer insulation looks dodgy, no triple insulated wire secondary.... and no, I don't see any input protection, even a fusible resistor or track.P.S. Yes, the dip package is an opto isolator, (as a rough guide for scale, the distance between opposite pins is the required safety clearance). Don't worry about the capacitor brand, it would murder you before you need to worry about it. In short, it's dodgy as hell.

author: gamalot
author_rank: Super Contributor
timestamp: July 27, 2025, 08:07:33 pm
content: The real Amazon charger is made by Flextronics (now Flex, 伟创力), the world's second largest electronics manufacturer.