Can anyone recommend a budget USB power tester?

[Cyber Akuma]

Never used one of these before, and I need to test how much power some special-purpose USB ports will pull. When I tried to look it up the top results I was led to this thread on this forum:

https://www.eevblog.com/forum/testgear/which-usb-power-tester-do-you-recommend/

... and other random websites recommending everything under the sun.

Only issue with the recommendations is that they are pretty expensive, about $70-100, the cheapest one (for the links that still work) was $40.

I know there are many on Amazon that are around $10-15, but I have no idea how much I can trust those or if they would just be trash. Are there any that are $30 or under (Preferably $20 or under) that one can recommend that are decent? I am not looking for one that has a ton of bells and whistles or features, if I ever need something high-end I can try to save up for that CT-3 that was recommended in that thread, for now I just need to see how much voltage and amps a USB port I need for a project can pull. I noticed that even Klein has a $18 one, the ET900. Is that one good? I know they make good Multimeters but I am not sure about their other testers, or are there better ones one can recommend for that price range?

[Gyro]

I'm not sure what you mean by special purpose USB port, but if you're just interested in standard 5V USB voltage, current and mAh, I've found this style to be simple and effective: https://www.ebay.co.uk/itm/194913261069 (UK link but I'm sure you'll find them in the US). Obviously no good for 12V USB-C chargers etc.

[Dave_g8]

Hi,
For basic measurements, the UM25C works quite well. It costs around £20~£25 in the UK, it was £14 when I purchased one in 2019.


There are two versions, the “UM25” and “UMC25C”, the latter supports Bluetooth connection which can be used with PC software or Android APP, allowing control, monitoring and logging.
The specifications for the UM25C meter are shown below.


Example information shown on the display is shown below.


Example information available using the Android APP, including an exported XLS file is shown below.

[TomKatt]

I’m no expert in usb protocols, but there are several power modes usb devices can negotiate when connected.  That’s why I splurged a bit and got the FNIRSI FN58 ($60).  But that’s also because I can justify the expense for work IT maintenance.  It’s also important to verify the usb protocol being used in addition to volts / amps / watts.

The UM25 mentioned above seems like a good compromise if you’re on a budget.

[DaneLaw]

.. and I need to test how much power some special-purpose USB ports will pull. ..

What is special-purpose USB ports?
IF you don't have any already, and you just need crude in-line USB meter to see what amp/voltage that are taking place, as something is better then nothing, then just start out with one of the cheaper ones, that got both USB + TypeC sockets, as nowadays many products are using TypeC.
These dual socket meters (TypeC male+femal and also incl. USB-A male+female) price-wise starts around 5 bucks (delivered).
https://ae01.alicdn.com/kf/S75327298143a4f70bd7fab204cc8bf05z.jpg
But they don't have max log (amp/volt/watt), only the single sockets seem to have that, when it comes to these very cheap ones under 5 bucks.

[thm_w]

I bought the Fnirsi 48 but hate the UI design, its terrible to navigate and use for basic tasks. Save yourself the hassle and get a $5 USB-A one to start.

These look interesting for type C, but no type A
https://www.aliexpress.com/item/1005006822341040.html
https://www.aliexpress.com/item/1005006848187940.html

[shabaz]

Just to add another one to the pile of options; I have the one shown in the screenshot, for USB-C purposes.
I've never tried testing it for accuracy, but it's certainly useful for occasional tasks, to understand what voltage got power-deliveried, and the current draw.
I can't say if it is much better or worse than other products. I didn't spend a lot of time comparing specs at the time, I just had a need and it worked for it. There are different displays (including a real-time chart display with selectable speeds) but the main numeric display is the one I actually use, it's fairly readable from a distance too, despite being small.

EDIT: Found some action shots of it on my phone, I've added those.

[DaneLaw]

I bought the Fnirsi 48 but hate the UI design, its terrible to navigate and use for basic tasks. Save yourself the hassle and get a $5 USB-A one to start.

These look interesting for type C, but no type A
https://www.aliexpress.com/item/1005006822341040.html
https://www.aliexpress.com/item/1005006848187940.html

Got one of those, as sadly most of the other USB-meters I got, don't show max-logged values... one of the features (parameter) that sadly was dropped on Fnirsi FNB58, while the unit you mentioned Fnirsi 48 had that.

Use these (KWS2301C) on powerbanks/TypeC output, as its an easy way to see what max-amp/volt/watt took place with different PWM programs and voltages.

The mentioned dual socket ones https://www.aliexpress.com/item/1005006436199557.html? (haven't tried them, but one of the few budget options that both got USB-A M/F + TypeC M/F)

The USB-meter I reckon I used the most over the years, is these jack-of-all-trades. https://lygte-info.dk/review/USBmeter%20USB%20tester%20Atorch%20UD18%20%28Hidance%29%20UK.html
Mainly because of the DC-barrel ability .. got two of them, one is fitted with 2.1mm barrel DC connection and the other with a 2.5.

[pcprogrammer]

Be aware that with the cheap ones from Aliexpress the soldering can be wonky. I have two different cheap ones that both needed re-soldering of some of the parts.

One of them I ordered via the get 3 for free shipping and they send a different one then offered, disputed it and got my money back, so it was for free. It is similar to this one https://nl.aliexpress.com/item/1005006582906017.html where the display alternates between voltage and current, but the connections are on the short sides like the other one I own. The soldering of the display was flaky which I discovered when it twisted a bit while inserting into a USB port.

On the other one https://nl.aliexpress.com/item/1005006589627822.html I did not spot the problem in the beginning, but after several times of using it, connecting and disconnecting, it started to become unstable. After an inspection I spotted bad solder joints. Re-soldered them and it is working fine again. Did not check the accuracy though.

[Phil1977]

Be also aware that few of these devices loop through the LVDS-pairs for USB3.0, Displayport, Thunderbolt etc.

The FN58 is doing quite well regarding this, but it´s form factor is not so great for USB-C usage.

I have another €5-cheapo with USB-C on both sides where the lines are routed but not with the required quality for fast signals. A simple LED continuity tester shows they´re connected but even a simple HDD falls back to 480MBps.