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

Yes, probably.

I’d like one even if quite large.

not interesting for AT35. but it don’t have big change :frowning:

This page covers specs of the RD devices

And this is good for logging data, it can output JSON

One thing I’ve noticed with my RD power meters is that the USB sockets seem to wear out and gives an increased voltage drop

thank you for your share,. it is great . for voltage drop, could you show me ?>

Bad day, my faithful YZXStudio 1270 has seen his display crushed. It is serviceable ? If so where to find a replacement screen, or who could repair it ?

Anyone ?

I have an issue with my TC66C, which I bough off Aliexpress on your official store:

I use the RD-TC66C in “PROTOCOL DETECTION” mode, with this item:

Baseus 45W Quick Charge 4.0 3.0 USB Car Charger For iPhone Xiaomi mi Huawei QC4.0 QC3.0 QC PD 6A Fast Charging Car Phone Charger

I bought the model with USB-A + USB-C from Aliexpress, the model is “Baseus BS-C20C” and is written on the housing.

The issue is: when doing protocol detection everything goes on, until it reaches HUAWEI SCP where your meter powers off and turns on again. Could you check what is happening?

If I connect first a Samsung S10 phone to one of the ports, then the TC66C doesn’t reset but then the protocol results are not the same, maybe the ports of the car charger are not independent?

Related article: The Baseus BS-C20C in the test! USB PD, QC 3.0 and Huawei Super Charge in one car charger for € 10?!?

it is Baseus products problem,his charge is bad , he did not use standard charge protocol and use the third part protcol and miss something
at our product page , we write”our products are not compatibility with baseus product”, because his quality is not good, although they sell well, Ugreen charge don’t have any problem
for this problem , we have 2 solutions
1, in fact we already solves this bug , and you can connect PC software to update firmware , it will work
2, you can use micro power to power on , it will not show this problem

Baseus PD car chargers are trash and DANGEROUS. I bought two of the 30W PD + USB A on sale and both failed safety and functionality tests.

The problem you’re describing is mainly because the charger only works in BUCK mode, which is not specified anywhere so in order to achieve 45W output which is 15V3A you must have it connected in a 24V vehicle. Charger is unable to output above 9V and will restart when such voltage is requested.

Secondly the USB A and usb C port are not well isolated for “dumb” usb devices. Normally when you connect a 9V and a 5V device simultaneously the charger must restart to provide 5V on both ends in case it can’t provide both 9V and 5V at the same time, however with the baseus car charger it will simply provide whatever voltage it’s on the C side as long as the A port device isn’t requesting any specific voltage.

In order to perform the above test I used iPhone X with fast charge cable and a cheap lantern that I quite liked on the other end and the instant 9V charging via micro USB blew the resistors. $10 lantern lost because of a $5 charger.

I like that Baseus charger because displays the voltage of the car, the voltage being outputted and the amperage being outputted.
I have used TC66C on a 24V car and has the same issue, it’s not the voltage that makes TC66C reset when doing PROTOCOL DETECTION.

[quote=RD tech]

Ok did some more tests and this is what I’ve found:

- TC66C Firmware upgraded from 1.13 to 1.14

- Now if I connect the TC66C directly to the C port of the Baseus your meter doesn’t turn on: Baseus <-> TC66C
— However if I use C to A and A to C adapters in the middle then it turns on: Baseus<USB C to A<>USB A to C<->TC66C. Why is this difference happening, is that the adapters modify something in the middle?

- If I connect the TC66C to the A port on the Baseus I need one A to C adapter and turns on again without load.

  • PROTOCOL DETECTION detects everything as green when connected to C port on the Baseus and battery is 24V. If I connect to A port it’s the same result but TYPE-C PC is red instead.

  • Which protocol Baseus does not meet properly?

While using C to A and A to C again you will just have the A protocol.

Looks like the Baseus is causing the problem.

Using just one of them already implies using A protocol? I though all data was preserved and it was just a physical change.

Yes, since USB A has just 4 wires (+5V GND TX and RX) whereas USB C has 24.
Data will be preserved though. But you loose all the options of USB C

More info on the issue:

- When connecting TC66C or any other USB-C power meter, like Satechi or Plugable, directly to Baseus C port, power meters don’t power on until I connect some load like charging a phone. If disconnecting the load, the meter powers off again.

  • However, If I connect a USB-A meter like YZXstudio to the A port of the Baseus, it powers on immediately even with no load.
    Doesn’t this make sense, since PD prevents from sending power until some specific bus data is received? Or power meters already send some signal so it should power or? I don’t have any other PD wall or car charger to test it so I don’t know how it should behave.


Now if I connect the TC66C directly to the C port of the Baseus your meter doesn’t turn on: Baseus <-> TC66C—- this is not charger and TC66C problem, this is PD charger feature, if you want it turn , please turn on our PD switch, it will turn on

Tried again connecting TC66C to C port of Baseus, but still doesn’t power on without load. Tested with buttons C and D of the meter in all 4 available positions but still doesn’t turn on.

thank you for your reply, could you make a video to show me ?

Hi, I sent you the video to your PM. You can see how I connect the meter in all 4 available positions of the switches, and it never turns on witout load. With load, sometimes the meter screen powers on and others not, but always charges the load when connected. By the way, the car charger specific model is the Baseus BS-C20C, it’s written on the case.

Related article: The Baseus BS-C20C in the test! USB PD, QC 3.0 and Huawei Super Charge in one car charger for € 10?!?