nexus 5x usb-c
Devices like the Nexus 5X could be damaged by poorly-designed USB-C cables. Justin Sullivan/Getty Images

Users of a device that charges via USB-C should be alert. Google engineer Benson Leung discovered on Saturday that two of OnePlus' USB-C accessories do not use the correct identifier resistor, meaning that plugging it into certain smartphones to charge could cause damage to the device. This includes the Chromebook Pixel 2015, the Nexus 5X and the Nexus 6P.

It's not just OnePlus who is at fault. Leung, a software engineer that works with the Chromebook Pixel and Pixel C teams, has been reviewing other cables on Amazon and discovered a wide range of cables that claim to conform to the USB-C specification, but instead are designed in a way that can cause damage to devices. Shamed brands beyond OnePlus include Qube Gadget, Amzer, LightningKid and WinPlus.

Leung explained that the OnePlus USB-C to Micro USB adapter should be using a resistor with 56 kilo-ohms, while the cable in question uses a 10 kilo-ohm pull-up resistor. When the adaptor is used to charge a device, it could attempt to draw more power than it is capable of.

This will be less of a problem with the OnePlus 2, Leung explained. The device does not support fast charging, meaning it is less likely to draw enough power to cause damage. However, Chromebook Pixel 2015 owners should be warned, as the charger could potentially cause real damage to the laptop.

USB-C is a relatively new standard, which famously became the main connector on Apple's new MacBook range. The connector has found its way into more and more tablets and devices, and the launch of Thunderbolt 3 is expected to spur adoption further. Intel's latest Thunderbolt connector uses the same plug as USB-C, meaning it may not be long before high-end workstations start adopting USB-C into their designs.

Leung's warning is a sharp reminder to stay vigilant and avoid buying cables from suppliers that have not been properly tested, particularly in the case of standards that are relatively new to the market.