The Dangers of Cheap USB Chargers

All USB chargers look alike, they all have the same familiar USB socket – they must all be the same, right?


USB chargers are complex pieces of electronics with over 50 components all working together to get the charge bar moving across your smart phone or tablet. They handle the difficult task of transforming the potentially dangerous 240V AC mains power from your wall socket to a safe 5V DC – and all of this often in a space smaller than a golf ball.
There have recently been a number of media reports about chargers catching fire, damage to mobile phones, and even electrocutions and as engineer and blogger Ken Shirriff reports, there is a big difference between the genuine Apple i-Phone or i-Pad charger and the many cheaper “phony” Apple chargers out there. Unfortunately an Apple logo on the case or a CE mark on the product label is no guarantee that the product is actually safe.

Firstly, the cheaper chargers are often not rated correctly and lack adequate overload protection, i.e. they may claim to be 10W chargers but they are actually only able to safely output 5W – that means slow charging for you and the danger of overheating if the device tries to overload the charger.

Secondly, safety in the design and specification of electronic components is especially critical and, as highlighted in Ken Shirriff’s report, the essential separation between high and low voltage components is one area where the “phony” chargers skimp – often with potentially dire consequences!

Another area where cheap chargers often fall short is in output noise. An ideal charger would supply the USB socket with a smooth 5V output, with little or no variation. Cheap chargers, on the other hand often have huge spikes and the voltage levels vary wildly, with peaks over 6V and troughs under 4V. A recent blog post by repair business MendMyi has reported a common problem with iPhone 5s that don’t charge as a result of damage to the USB charge chip – and they attribute this directly to dodgy chargers, whereby the high input voltage spikes, provided by the charger, cause damage to the sensitive internal electronic components of the device.

But if danger and damage are not enough, electronic chip manufacturer Cypress discuss in their technical note on noise in mobile devices how a noisy “bad charger” can make using the touch screen impossible while charging. Apparently the noise from the charger disrupts the sensitive electronics that measure the position of your finger on the screen. So if your Angry Birds aim is a bit off – maybe upgrade that charger.

OE group TUF brand chargers are designed to safely output optimum charging power to a wide range of devices and they have been tested and certified to the highest levels for Safety and Electro-Magnetic Compatibility by independent test laboratories. In addition, every TUF charger is individually tested at three times during the manufacturing and assembly process, so you can be assured of a quality product!

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