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"Is the battery in this gadget accepting a charge?"
I'm amazed at how often I'm asking one of the above questions when I'm examining a broken, malfunctioning, or otherwise misbehaving device.
USB ports are everywhere, and it's no coincidence that USB port problems are an increasingly common issue that those who diagnose or repair gadgets have to face. And without the right tools, you can be left tearing your hair out trying to figure out what's wrong.
The tester is a low-cost tool that allows you to test the output of chargers and power banks. It's also a way to check the rated capacity of a device or the condition of the battery.
The adjustable load gives you a "fake" device to plug into a power bank or charger to act as a load, so you can see if the device is working properly. One note of warning here is that these adjustable loads get hot when used -- really, really hot -- and it's advisable to get a heat-resistant surface to put them down on when in use.
The tester comes with an instruction manual, and while it's better than nothing, nothing beats experience. The best way to learn how to use this device is to experiment.
One feature that makes the KJ-KayJI 2 in 1 USB tester easier to use than many is that there's only one button to press -- a short press moves you between the different screens on the display, while a long press resets all the readings to zero.
Plug the tester between a smartphone or laptop and a charger, or a power bank and a load, and see what results you get. The more you use this tool, the more you'll understand what a charger or power bank should output (you can usually find this information printed on the charger or power bank) -- and the better you'll be at spotting when something isn't right.
This is a great USB tester that's ideal for those starting out on their diagnostics and repair journey, as well as experienced users who want a spare tester. I have a couple of these testers and I find them to be just as good and just as accurate as testers costing two or three times the price.