USB power meter/tester thread - YZXStudio, Power-Z, RDTech and more.

I can totally vouch for Frankie and the 99centHobbies store. The YZXStudio products arrived in 12 days and he has replied to all of my email questions within a couple of minutes.

Looking forward for those reviews!
I will also order a YZX powerbank soon. Looks like gen8 is coming:
There is however nothing “budget” about YZXstudio products! :slight_smile:

I just got my ZY1270 from YZXstudio’s Taobao shop. It is neat and everything but the most interesting thing was that it was shipped by Franky Tong!
I get it - the reason why Taobao is in Chinese is that they don’t want to deal with export hassles. They rather have resellers on Ebay do it.

Hi everyone, since there’s an ongoing talk about the newer versions of the USB power meter and other YZXstudio gadgets I decided to turn this thread into a general discussion about YZXstudio devices. I have removed my powerbank tests which were not very relevant to the usb meter and will start a separate thread for all my existing and upcoming reviews.

So this is will be more or less an “Official” YZXstudio thread for BLF if you’re ok with it, since the users for these devices are limited I thought it is best to keep all the information and talking in one place. I will add an index to the OP pointing to reviews/first impressions/new products in and out of this thread, and since this is not my personal review thread anymore, please feel free to ask or add anything related to this. :slight_smile:

What do you think?

I think it’s a great idea, I have my eye on these, but was worried about the risk of buying it from eBay. Reading the above discussion makes me much more comfortable.

I have a cheapo version on the way from BangGood, if I wind up using it a lot maybe I will upgrade to the xyzstudio version.


I just received the YZXstudio 7th Gen 4-cell powerbank. The construction of this thing is top notch, and the available settings is astonishing! The most remarkable configurations are:

Set output voltage for both 5V and QC 9V (+0.5V)
-Set discharge cutoff voltage, charge termination voltage and current.
-Set battery charge current up to 4.5A (1A+ each)

I’m still trying to figure out some of the calibration features (the UI is in Chinese only), but so far I have correctly calibrated battery capacity and battery full voltage.

4x Sanyo GA as battery source

1x 5V & 1x 9V USB out, microUSB and 4mm input (shares the same plug as the sony PSP).



Close-up of the board, some of the components are never seen in any powerbank before.

I calibrated the internal voltmeter to match my most accurate DMM and the skyRC MC3000. It tops the battery at 4.207V

I haven’t done all of the output testings but I did a quick discharge test at 1.5A and got 94.2% efficiency. This is the highest effieicncy I’ve seen not only in a powerbank, but in ANY DC-DC boost converter.

Battery capacity as measured by MC3000 at 0.5A discharge rate, with D-reduce of 250mA down to 2.5V: 3380mAh, 4 of them makes 50.02Wh. Note that the sanyo GA does not reach the spec’d 3,500mAh in real discharge tests.

Output at 5.15V 1.5A by using the YZX dummy load: 47.12Wh

So far I’m amazed by the performance of this powerbank… to be honest this is one of the finest electronic device I have ever used. Will soon upload more discharge tests.

Haha - I was thinking before that this is probably the most awesome power bank ever made. It looks beautiful too. And expensive, I presume?

They will soon release gen8, which could have english menus but the cells are soldered because it supports drum roll 12A charging! :smiley:
I will order one as soon as it is available.

BTW - if you have trouble deciphering Chinese you can use Google Translate on your smartphone with camera image as your input!

At $60 and $25 for batteries it is not remotely budget, but it’s worth every cent!

I’m after Gen 8 as well, I like that a specialized DC adapter can be used to charge even faster than Quickcharge 2.0 or 3.0. The fastest charger I have for mine now is a 9V 2.5A car adapter for 22W+ output, even faster than a quickcharge adapter at 9V 1.8A. Both can allow the powerbank to push 4A to the batteries.

I’m using the google translate app, but some settings are translated as “Setting reference full power voltage”, so I really don’t know what that’s for.

I also got the ZL1000 dummy load with the upgraded Bourns multi-turn trimpot, so far it works as expected and runs relatively cool. Supports QC2.0/3.0 with auto coding request. Will upload a review after some more extensive use.

I got the YZXstudio 1270 Color OLED meter with Bluetooth a couple days ago and have been playing with it a bit… Since all the technical aspects have already been covered in HKJ’s review I decided to write a quick guide for importing the raw data from the bluetooth terminal and use them to make a graph in excel.

  1. Enter the settings menu in the meter and set the serial upload rate to anything but zero. My preferred interval is 30sec.
  2. Search and connect the meter to your smartphone, will be listed as SPP-CA.
  3. Download and run Blueterm app, long press the screen to select the device and start logging.
  4. Once done with logging the data, copy the file to your computer and rename the format to *.txt.
    In the file you’ll see the raw data like this:
  5. Open Excel, select “Data” tab and then “From text”
  6. Select your .txt file and then “Comma” as the delimiter
  7. After that you’ll get two lines of data displayed in ten thousandth, so divide by that and set the decimal places you like. Add time axis as well.
  8. Final step is to create the graph of your liking and you’re done! Note that I placed the AMP value in a secondary axis.

In this graph you can see how this powerbank fails to deliver a healthy voltage half the discharge cycle at a 1.5A rate, dropping from 5V to <4.3 is unacceptable.

The meter doesn’t send other important parameters such as capacity and energy, but you can calculate them using simple formulas. Here’s another example, rate set at 10sec this time.

Are also the owner of this meter and the lcdscreen looks fascinating with 0.1 values
wicked the amount of sellers listing this as usb3.0 and precirurius how an typo (that seems to originate from its version3.0 get evolved to USB3.0 and then just gets a life of it self, and is more the case then none ’ the amount of sellers listing it as usb3.0, ewen thow its clearly not one of ZXYstudios USB3.0 meters.

the Bluetooth-datalogging in raw format of the 2 values, are there aint any apps that on the fly put them into an graph or manage them in a more pleasing way for the beholder…
I tryed the OWON app for there BT DMM and ewen thow there older BT2.0 APP reconize the SPP_CA (in regards to aint, on the owon bt4.0 app) it clearly wouldnt manage the values.

anybody on top’ of this ballpark and how this raw bluetooth-data is being managed and if there is any app-support to ex. win10/7, mac, android, windows phone that will play along with these raw stream of bluettoth-delivered-values and graph these string / hex values out on the fly, like you see on DMM datalogging software??. (certainly aint my field)

Thanks for that! It’s usable for any of the YZXStudio meters that have bluetooth too :slight_smile:
Now I need to buff up some on my excel (numbers) and math skills to figure out the formulas you used :smiley:

It’s pretty easy… for Capacity (Ah):
First value: C = Current / records per hour
C1 = C + (Current / records per hour)
C2 = C1 + (Current / records per hour)
And so on… just drag down to replicate the formula for all fields

Records per hour = 3,600/serial upload date

For Energy is the same, instead of current use power.

Once you have the chart done just simply import new data for whatever you’re going to test. There is a very small variation in this calculated value vs the measured value displayed in the meter, but even at 10s refresh rate the variation was only at <1%. At 0.36s refresh rate the tolerance should be near zero, but that’s a lot of values to work with.


I've just bought the YZXstudio 1270 and I have a couple of questions.

I've bought the BT module separatly, but where can I find the small transistor and pins to be added it on the board?

I have 2 models, one is USB 2.0 and the other one USB 3.0. Is it possible to upgrade 2.0 to 3.0? If yes, how?


I’ve been messing around somewhat, thus far, I produced these :

I notice very strange things going on when playing around with QC charging…

Just got my YZXStudio 8th gen power bank. Seems quite good, when I tested it with a single Sanyo NCR18650GA.

Compared to a Miller ML102 (v9) it manages to squeeze out 11 % more energy (10.2 vs. 9.2 Wh) before shutting down. All while supplying a rock solid 5,13 volts from the usb output. I stopped measuring the ML102 after the output had dropped to 4.5 volts. Usually I consider 4,75 volts as the lower limit as per usb charging specs.

I just wired it temporarily to a 18650 holder before having 4 18650GAs spot welded to form a 4P pack.


It has been a year since I bought I bought my then ‘new’ YZXstudio usb monitor from Frankie Tong, and since then I have not kept up with the newer products.

This new powerbank has caught my interest.

I hope to read more about YZXStudio 8th gen power bank here or even have its own thread.

While searching online about YZXStudio devices, I notice there’s another model not yet referenced here: ZY1276, anyone who has this and have some first looks/reviews?

There’s also the ZL1100 load tester/protocol detector (it doesn’t have meter function? unlike the ZKE EBD-USB+ which is both a load tester and meter, but needs a PC and the software to view/control) from YZXStudio. There are a few reviews/images of the ZL1100 in the Chinese forum But otherwise, similarly hard to find further info about it.

Found them in YZXStudio Taobao Store (in Chinese though, may need to use a translator…)

USB快充協議測試儀電壓電流表容量QC4+PD3.1POWERZ檢測YZXSTUDIO - Taobao (select the image to the right that shows ZY1276)


I have the new ZL1100 which is basically a more functional and accurate version of the ZL1000, I’m still trying to figure out some functions but so far it seems to be an excellent discharger. And because it draws external power it can also be used to discharge test batteries.

Took a while to program data logging via serial port but I finally managed to do it, however I wish there was an option to set reading intervals.

Let me know if you need to know anything else about the ZL1100

Fancy meetin' you here, d_t_a :D

I did a little video about the ZL1100 a while ago, use it quite a lot in cabletests on my channel.

Same offer as above, ask away :)

I'm pondering the ZY1276, but it doesn't really do anything that I can't already do with my collection of YZXStudio stuff...