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.

The display is excellent. USB-C in either direction and allows all kinds of testing as long as you have a few USB-A to USB-C adapters (both male to female and female to male). The data seems accurate given that I know what kind of power I should see from/to a certain device. Although I am still confused by the calibration "feature" of this. It seems odd to need to do this, and when I tried it nothing changed. That probably means it wasn't necessary, but I wonder how wrong the data would be if it became uncalibrated and I failed to calibrate when necessary... and how do I know when I need to calibrate! I really like the mAh and mWh resettable readings as it gives a good way to test battery capacity and efficiency (how much power it takes to fully charge vs how much power you get out of it!) I suspect a lot of people buy these for testing something and return a month later, but I think for the very small price I'll keep this on hand.

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.

Great power meter, simple, beautiful screen, measures both voltage and current.

As advertised. I like buying seemingly cheap battery packs. It's like playing with fire. Literally. The coolest part to me is to find the best value. So I have to see if the 7,000,000 mah is real. Obviously not. I don't have 43 12v car batteries in my hand. Works great. Got it up to 19v and 30 watts. Cannot track 7 digit mwh and mah numbers, but no normal person needs that.

Used tester, checked, verified voltages, works great, found the charging issue and now ai know what parts to order to fix devices. Works as intended.. I mean it it literally has ONE job, it was kind of a low bar to begin with but it works fine.

Love this little device. I had a lot of chargers and cables that all seemed to perform differently with different devices. With the aid of this tool, I was able to definitively ascertain and verify the capabilities of each charger and cable once and for all.

Does what it says it does

Sehr praktisches Gerät für USB-C (Lade)geräte. Die Anzeige ist gut zu lesen, auch bei heller Umgebung. Es gibt "USB-C" - Geräte, bei denen nur der Stecker passt aber keine echte USB-C Aushandlung passiert. Diese werden hier sofort "entlarvt", da sich das Gerät dann gar nicht erst einschaltet ;-) Sehr praktisch finde ich, dass das Gerät bidirektional arbeitet - man kann also entweder das Kabel oder die Buchse als Eingang wählen. Die Richtung wird automatisch erkannt und angezeigt.

Il tester per porte USB C è utilissimo ed affidabile, consente di misurare i valori di tensione e corrente e calcola il valore dell' energia assorbita durante la ricarica, consentendo di conoscere la capacità reale della periferica in carica e verificandone la capacità residua. Ottimo prodotto, non crea impedimenti o surriscaldamenti. Grazie a tale prodotto ho scoperto che uno dei miei computer portatili, pur avendo la porta USB C, non consente la ricarica tramite la stessa. Consigliato per diagnostica e verifiche varie.