Danger lurks in counterfeit iPhone/iPad USB adapters

Danger lurks in counterfeit iPhone/iPad USB adapters

Summary: Recent testing of USB chargers for tableta and smartphones shows that Apple's dongles rate well above average, but the fakes could be hazardous to your hardware investment.

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TOPICS: Apple, Hardware, iOS, iPhone, iPad
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A recent blog post by software engineer Ken Shirriff tested a dozen USB chargers sold worldwide: both the versions that come in the shrinkwrapped box from the manufacturer, as well as third-party products. It also looked at counterfeits. The article asked the question whether "a charger provides silky-smooth power or if it is a dangerous charger that emits noisy power that cause touchscreen malfunction and could self-destruct."

The article offers a wealth of detailed information on chargers, including tear-downs, photos, voltage quality tests and frequency plots. It also looked at whether the charger delivers the advertised power. Some hit the mark, while others were way off.

The counterfeit chargers perform extremely poorly, putting out a fraction of the expected power. Charging your device with one of these chargers will be a slow, frustrating experience. In particular, the counterfeit UK charger only produces a third of the expected power. Although the label claims the charger works on 100-240 volts, it's clearly not designed to work on US power.

Shirriff noticed a voltage sag issue with the iPad charger. He found it puzzling.

Similar to the iPhone charger, the iPad charger shows a lot of voltage sag. The voltage is about 5.1 V unloaded, dropping to 4.4 volts and 2.3 A (10.1 W) at the corner. Unlike the iPhone charger, the iPad charger has pretty good current stability. The regulation is solid, as shown by the narrowness of the yellow trace. Note the scale change due to the high current output.

I'm puzzled by the steep voltage sag on both the iPhone and iPad charger. Since the designers of the Apple charger went to a great deal of effort to build a high quality charger, I conclude they must not consider voltage sag worth worrying about. Or, more interestingly, maybe they built this sag as a feature for some reason. In any case, the chargers lose points on this.

He also suggests that users should make sure to use the correct charger for their phone model; for example newer iPhones.

Perhaps consider CableKeeps by Nice By Design; I use them with my own power adapters. These covers slip over the adapter and look like little blue, green and orange fish. They let users wrap-up the cable for storage, identify the adapter and more-easily pull the plug out of the power socket.

Topics: Apple, Hardware, iOS, iPhone, iPad

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6 comments
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  • Wow.. life in the Mac world must be very dull....

    Seriously, satisfaction ratings for third party USB chargers?

    Really, it comes down to one thing: does the charger deliver 2.1A sustained at 5V. Any that do will be essentially identical.

    The exceptions are tablets which have special 'fast' modes like the Asus Transformer line. Their power supplies sense that they're connected to a Prime and kick up the voltage to 15v for fast charge (and kids - don't try this at home - the tablet has to have special circuitry to do this without frying the tablet).

    More importantly, as I recently discovered, most tablets (iPads included) can charge with supplies that deliver less than 2.1A@5v, it's just slower. But if you leave your tablet docked when you're not using it, it trickle charges all the time and is pretty much always charged up.

    So, really, there's no big problem here...

    Well, unless you're the anal retentive types who actually measure these things and then make a big deal when it's not exactly what you want...

    In which case, stick to branded products made by the manufacturer and enjoy paying the highest price possible... but hey, that proves you must be better than everyone else, since you can afford 'the best', right?
    The Werewolf!
    • Points

      For smugness. Demerits for reading comprehension.
      ewelch
  • It is also about safety - this is the real important message

    This article should have emphasised the more serious message from Ken Shirriff's article: that the counterfeit charges "ignore safety standards." His teardown of a counterfeit charger shows they have inadequate electrical isolation.

    Not all charges are designed and manufactured to the same standards. Manufacturers of counterfeit goods aren't going to spend the time and expense to satisfy safety standards and regulations; nor pay experienced engineers who know and care about such things.

    As consumers, we see the style on the outside and can easy assume all chargers are the same. But Ken Shirriff looks on the inside and sees that you are paying for real substance.

    To avoid taking unnecessary risks of getting electrocuted or your house burning down, paying an extra $27 seems a small price to pay.
    Hoylen
    • Fires

      On top of Hoylen's comments, phone chargers (counterfeit or not) are frequently cited as causes of fires. It sounds stupid, but turn your charger off or unplug it when not using it!
      DJL64
  • Counterfeit & underrated USB adapters are dangerous.

    Counterfeit USB adapters are surely to avoided but underrated/undersized USB adapters are dangerous also since they can provide enough power so if they don't have the proper internal protections can overheat and could cause a fire hazard when the device attempts to draw more power than the USB adapter could deliver.
    I had someone here at work got one of those "cheap" USB adapters and one time when they wanted to recharge their nearly dead iPhone they USB adapter overheated & since there was no proper protections in the adapter it started to smoke and tried to remove the adapter out of power strip and it melted so I lifted the adapted but left the two AC prongs in the power strip with the metal exposed then immediately I turned off power strip. I was helping this person at that time for unrelated issue so it was a good thing I was there to help the person and it was in a power strip or it would have a bigger problem trying to locate the circuit breaker for the electrical receptacle. I asked that person where they bought the USB adapter and that person bought it at an flea market thinking it was a compatible USB adapter and all I had a melted blob of plastic so i couldn't identify anything of USB adapter so I couldn't identify who made or anything about it.
    I agree David & Ken, there are a bunch of bad USB adapters out there and we need to know about them and have someone to check these out before something dangerous happens.
    phatkat
  • Accessories on Amazon

    One place notorious for counterfeit accessories is Amazon.

    Just try to get a genuine Apple accessory on Amazon. A zillion Chinese knock-offs, which fail within a couple of weeks.
    varase