YOJOCK USB C Tester Power Meter 4-30V 0-6.5A Digital Multimeter, Type C Voltage and Current Tester Meter, Power Capacity, Working Time Ammeter Voltmeter USB Cable Charger Detector (Classic Version)

This little tester is a must-have for anyone working with USB-C charging. I’ve used it to check power output, charging speed, and cable quality — and it gives fast, accurate readings every time. The screen is clear and easy to read, and the build quality is solid. I’ve purchased it twice now and it’s never let me down. Highly recommended for techs and tinkerers.

I like working with USB-C. I also like working with USB-C out of spec; the cable's very convenient, small, plentiful, and cheap; I have lots of male and female breakouts. I've found the device will accept down to right around 3.5V before cutting out (perhaps at the expense of accuracy, but it has seemed within expectations with most LiPo cells meeting their rating). The 3.5V minimum makes it unsuitable for single LiFePO4 cells, but you can run two in series and be fine; it is also almost fully useful for single LiPo cells given their "voltage cliff" in capacity through discharge; you will miss out on capturing maybe 5% of total capacity, and discharge that low is bad for battery lifespan, anyway.The neat thing about it handling higher voltages is that my DIY power sink is also reasonably voltage-tolerant, so I can still capture full Ah and Wh I need without adjusting anything -- but if I needed to, I could also move a linear regulator downstream of this wattmeter device (into my sink circuit) and get 5V out without introducing the huge inaccuracies which would come from having the regulator upstream of this wattmeter.Though from a cost/value perspective, I would say this device is essentially already perfect, a feature I would appreciate in a future revision or separate "power-user SKU" is a programmable voltage cutoff, where the device would flip a relay; or the cheaper/simpler option may be to close the circuit when the screen shuts off at ~3.5V, and this would be suitable for single-cell LiPo testing without risking dangerous overdischarge (though it was not too much expense or trouble to rig up an auto-cutoff myself in the power sink circuit with a relay and a comparator IC). I'll grant I'm probably in a pretty small niche of people who would appreciate that, though; there may not, in fact, be dozens of us.

Excellent gadget to be able to confirm the power delivery to my electronic devices. This one reads a slightly higher power delivery compared to my previous one, of course using the same power brick/cable sets.

I bought this mainly to test whether chargers and cables are working, but of course it tells you more specifics. Just plug it it between the cord from the charger, and the laptop or whatever, and it works.However, it's a little picky:1: I plugged it into a smart USB-C charger, and a load into it (I tried a laptop, some Raycon earbuds, and an iPhone via a little adapter), and it worked fine. Though when the iPhone went to sleep, so did the meter.2: I plugged it into a smart USB-C charger but did NOT connect a laptop (or whatever), and it did nothing (probably due to the smart charger not seeing a real load).3: I plugged it in to a USB-C charger "backwards," and it didn't work. That is, I plugged its cord directly into the charger and a laptop into it, and it didn't do anything.4: BUT, plugging it into a cable from a dumb USB-A charger or a dumb USB-A battery pack, it came alive fine whether or not something was plugged into the other end (laptop, iPhone, etc). It showed zero current if nothing was plugged in (as it should).So overall it works pretty well. Just make sure you either plug a load into it, or use a "dumb" power supply. One to keep handy so you don't get tripped up by a dead outlet, wall wart, or cable.

I used this product for amp draw testing of devices being charged. It helps with determining exact draw. The view options are also simple.

Works well, good display

Two major issues with this unit, which are both fatal for my needs.1) There are several power supplies which work perfectly without any power monitor and with every other power monitor I have tried but will not work with his power monitor. The phone will beep like power has been connected, the unit will show 5V, but the current will remain 0A and the phone will display a message that something is wrong with the charger. This happens every time with certain chargers or computer USB ports, and never with others.2) This is supposed to work up to 6A. But if the displayed current exceeds about 4.5A, the unit resets. The screen goes black, then the display lights up, displays the startup logo and the regular screen comes up. It correctly displayed the voltage of about 9V. The current starts increasing from 0A till it reaches about 4.5A, at which point it resets again. This cycle continues. A second monitor in series shows a steady voltage of 9V and current of about 5A. This stops happening when the current falls below a certain threshold around 5.5A.This unit is going back and this manufacturer is being blacklisted.

This is a great USB-C tester. It matches very closely my other tester, but is easier to use. Data is a bit small for my old eyes though. I have gone as much as 103 Watts which is the max my best power bank can go.