Buzz
Conveniently, I just bought a new charger so I got this to test its power. This is the Juwei J7-c USB current meter, designed to measure the output power of phone chargers, power banks, and more.General Information
What I love about this USB Tester is its versatility, supporting both Type A and Type C ports with pre-labeled Input/Output indicators. Simply plug the charger into the corresponding port. According to the seller's information, it also boasts a high measurement capacity, accommodating voltages from 3 to 30V and current intensities from 0 to 5.1A, allowing for a maximum power measurement of up to 150W, covering various types of phone chargers available today.The product only includes the USB itself without any usage instructions.
Testing Phase
Testing ZMI 30W 2-port charger with iPhone 12 at 18% battery.
The C port of this charger supports USB Power Delivery standard with a maximum power output of 30W. iPhone 12 supports PD fast charging up to 20W using C to Lightning cable. The measured power output averages around 18W, occasionally reaching 19.6W but too fast to capture 😁. The color display provides clear information on voltage, current intensity, and power.
The A port supports Apple's 5V-2.4A protocol, equivalent to iPad 12W charger. Using a regular lightning cable, it measures at 11.3W.
I don't have any high-powered chargers like 150W to test, so I'm not sure if this J7-c can deliver as advertised. Those who have tried it, please comment below.Additionally, this USB also offers some other features such as setting a charging cutoff time and setting overvoltage alerts, but I don't find them necessary so I haven't tried them and probably won't use them. I just use it for measuring.To Buy or Not to Buy?
I bought it for 260k on Shoppe. You should buy it if you want to test the actual power output of chargers or power banks. Don't buy it if you only want to test cheap, unbranded chargers or power banks. It's 2021 now, there are plenty of branded accessories available with diverse options, good quality, and reasonable prices :D
