Advice sought on why 6.8A USB charger melted USB cable today

[nospam]

in general it is, but there are always exceptions.

however, the issue is not so much price, but noname crap.

[nospam]

open them up and look. the noname shit is usually garbage.

Safety probably isn't something you think about when you plug in your charger, but it's important. Inside the charger is 170 volts or more with very little separating it from your iPad and you. If something goes wrong, the charger can burn up (below), injure you, or even kill you. Devices such as chargers have strict safety standards[14] - if you get a charger from a reputable manufacturer. If you buy a cheap counterfeit charger, these safety standards are ignored. You can't see the safety risks from the outside, but by taking the chargers apart, I can show you the dangers of the counterfeit.

in the chargers, he finds that the apple charger has a 5.6mm gap between high and low voltage sections but only a 0.6mm gap in the noname charger, which is so little that he considers it unsafe.

the transformer wires on the apple charger are triple insulated, while on the noname charger, they're uninsulated except for a varnish.

and that's not the only problem. the output is crap:

Lab measurements of the output from the chargers shows a couple problems with the counterfeit. First, the counterfeit turns out to provide at most 5.9W, not 10W. Second, the output voltage is extremely noisy and full of spikes.

noname chargers are not safe to the point where apple even offers a discount on a genuine charger to replace the shitty ones.

?There are plenty of reputable companies that make accessories for Apple products, and as long as you go with one of them, you should be fine,¹ says David Price, online editor at macworld.co.uk.

Charging your phone is a safe activity, but even plugging a device into a wall carries some risk. A Chinese woman reportedly died when she answered a call on her iPhone 5 while it was charging and an iPad giving a man such a strong shock that it sent him flying across the room. There have been enough high-profile incidents around iOS devices that Apple stepped in to provide discounts for its official ones. Even so, that didn¹t stop Tim Tyrrell from getting a knock-off charger for his iPhone 5 and suffering the consequences.

Tyrrell didn¹t want to spend the $25 ­ $30 that chargers from Apple usually cost, so he opted for a $10 combo from eBay that included two wall chargers and a car charger. Unfortunately, one of the wall chargers exploded, leaving Tyrrell with a nasty electrical burn. ³Basically, the charger turned black and, it¹s where the USB cord connects to the outlet, had a mini explosion,² said Tyrrell. ³It kind of bruised the fingers inside where I plugged it in.²

actually, they're not that simple anymore. most of them are much more than a transformer and a voltage regulator.

nothing is perfect, but the chance of problems with a reputable name brand charger is *much* less than with a noname charger because reputable companies have *way* too much to lose if they ship garbage.

nobody will notice if a noname company goes away, and it will reappear with a different name next month shipping the same crap.

[Bruce Sinclair]

As I said. Tiny. Not even a factor of 2 (that engineers routinely use), let alone a factor of 10 (that starts to make things interesting). :)

[Bruce Sinclair]

.. sadly these days, price is not an indication of quality. Neither is a brand name. Particularly since high and low priced, and "brand" and non brand products are largely made in the same factory. :)

[Bruce Sinclair]

Um ... what data do you have to back up that assertion (which seems completely wrong IME :) ). Chargers that come with apparently "quality" kit seem to crap out about as often as the non brand ones from what I've seen.

Beware particularly the "switchable voltage" supplies ... where it is possible to select 2 voltages at the same time (not good for the plug pack I can assure you :) ).

Chargers/power supplies are really simple things. Yes, manufacturers could cheap out and use nasty capacitors (saving a few cents) ... and yes I'm sure that happens. But why do you think this *doesn't* happen in the 'brand' or expensive ones ? Paper work and quality resultsa can be faked (easily). :)

[Davoud]

Davoud:

Danny D.:

But if you buy a name brand, be it Apple or Dell or whatever, you will get a product that was designed by the seller's engineers and that is manufactured under the seller's eye. Can there still be problems? Sure, but the odds are much better that you will get a safe, quality product. The off-brand products tend to be made in little sweatshops, people's kitchens, wherever, without the benefit of engineering knowledge or QC.

[The Real Bev]

I bought some nice lighted Belkin USB cables at the 99-Cents-Only Store. A few weeks later I saw them for $10 at Fry's. Same package. I love the 99-Cents-Only Store.

[Davoud]

Bruce Sinclair:

It ain't necessarily so. In my 10 years living in Asia I found that the quality products were designed by U.S. engineers and manufactured in high-end facilities. The cheap junk was often farmed out by packagers/exporters to family workshops, forced child labor in schools, etc. The maker got a crude diagram and boxes of the cheapest available parts, and assembled the items without oversight or QC.

[nospam]

not only that, but with a name brand, you get a company to go to if something does go wrong.

with a noname brand, you're screwed, and the magnitude of the problems are bigger. see my other post for just how shitty a noname charger can actually be.

[Bruce Sinclair]

I disagree on both counts. :)

[Bruce Sinclair]

Then your experience differs from mine. :)

[Davoud]

In article , Davoud:

Bruce Sinclair:

How long did you live/travel in Asia, and where did you live? That could explain our differing experiences.

[Danny D.]

Bruce Sinclair wrote, on Tue, 01 Dec 2015 23:43:08 +0000:

Let's agree to disagree. We're not talking "safety" factors (where a doubling is routine). We're talking specifications.

If I gave you a 40 amp circuit breaker and it kept switching at

34 amps, you'd not be so cavalier about the huge difference.

Likewise, if I told you something was 34 dollars a month, but it turned out to be 40 dollars a month simply because I lied, you'd again not think to be so nonchalant about it.

[tlvp]

Bought any resistors or capacitors lately? Resistors are commonly sold with nominal values +/- 20%; capacitors, with +100/-50%. +/-15% may not be high precision, but it's better than common precision :-) .

And anyway, 35 isn't a whole 15% less than 40, it's only 12.5% less, if we're going to try for highest arithmetic precision here :-) . No big deal.

Cheers, -- tlvp

[cl]

Bad example! Have you looked at the tolerance on the trip current of a circuit breaker? It may not trip below 40 amps but don't expect it to trip at 41 amps, not for a very, very long time anyway!

[cl]

In the UK (and Europe in the main) your claim if something doesn't work or isn't to specification is against the seller. You have no rights against the manufacturer unless you bought it direct from them (though in some cases they *may* offer service). Thus it doesn't matter at all if something is branded or not, you still have a claim against the seller.

[Danny D.]

cl wrote, on Wed, 02 Dec 2015 10:27:09 +0000:

But that was what I was trying to get at. If a 40A breaker consistently tripped at 34 Amps, you'd likely be upset.

To me, when watts are not only expensive, but 5 Watts is the typical output of *many* single USB ports out there, so, to mis-state the power by 5 Watts is a big deal.

Do you ever wonder why they never underestimate the wattage? For example, you'll almost never see it listed as 29 Watts.

Why is that the mistake is almost always an over statement?

[Danny D.]

tlvp wrote, on Wed, 02 Dec 2015 01:30:49 -0500:

If I bought a precision resistor, and it was off by 15%, I'd be upset.

[trader_4]

But you didn't buy a precision USB charger either. You bought a typical made in China widget, marketed not by Apple, Sony, etc, which typically vets those products, maintains some control over them, but by a company called "Hype", which could be run out of someone's bedroom for all we know. It's typical that these have documentation errors, language translation errors, etc. And some of them are just junk on top of that.

You said you bought over half a dozen. Have you tried another one? If it works, send the bad one back. If it doesn't work, send them all back and get another product.

[nospam]

that just changes who remedies the situation. it doesn't avoid the failure.

the best way to avoid a failure is by buying quality parts. if you buy noname crap, the chances of a failure are quite a bit higher.