UNI-T UT658 USB Tester

The UNI-T UT658 is a compact USB tester shaped like a USB drive, designed to quickly check the voltage, current and charging capacity of USB-powered devices. It works in plug-and-play mode with no batteries or installation needed: simply connect it between the charger and the device. Fitted with a USB 2.0-compliant USB-A plug (input) and USB-A socket (output), it works easily with common accessories. The backlit LCD screen shows operating values in real time, making it easier to diagnose cables, mains chargers and car chargers that operate within the standard USB voltage range.

The tester measures voltage and current accurately, helping you determine whether a charger is working properly or whether a cable is causing energy loss. The capacity function (mAh) shows how much energy was actually delivered to the device, which makes it simpler to compare different chargers or cables. Memory for up to 10 measurements lets you review results from different devices without writing them down.

Its compact housing fits comfortably in a pocket or accessory pouch. The tester supports voltages from 3 to 9 V, so it is not suitable for testing fast-charging modes that operate at higher voltages, such as certain Quick Charge or Power Delivery modes at 12 V and above.