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I have an HP laptop which I charge with a USB-C charger through the USB-C port. I have no idea which power delivery (PD) version it has and if it's PD-compliant at all. However, as the charging works, he-he, I assume it is.

On the HP website reference page about power delivery I read this:

Some 2015 or newer HP commercial notebooks can draw power from an external device such as an AC adapter, at different input voltages such as 5V, 9V, 10V, 12V, 15V, and 20V voltages. Not all voltages are supported on all models.

And the same voltages I recognize on my Baseus EU910 charger:

DC 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/3A, (60W max)

Can one check which voltage is used by the charger or consumer at the moment?

I inspected other questions on this topic: 1, 2, 3, but none of them exactly addresses my question.

I am aware that some kind of negotiation is held between the PD provider and the PD consumer, when they decide which voltage they will use for the current session. For me, it looks like pretty possible to get this information with some AIDA64-alike tool or programmatically via WMIC, etc. Is it?

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  • 1
    I don’t think this is possible. However, there’s plenty of USB power monitors available. They may also support other standards, such as Qualcomm QuickCharge. I cannot recommend one though, never tried it myself.
    – Daniel B
    Nov 28 '21 at 13:20
  • Have you seen these things before?
    – Hearth
    Nov 29 '21 at 3:06
  • cool stick. No, I haven't seen them for USB-C, only for USB-A
    – Suncatcher
    Nov 29 '21 at 6:57
7

You may try the Nirsoft BatteryInfoView:

BatteryInfoView is a small utility for laptops and netbook computers that displays the current status and information about your battery. The displayed battery information includes the battery name, manufacture name, serial number, manufacture date, power state (charging/discharging), current battery capacity, full charged capacity, voltage, charge/discharge rate, and more...

Knowing Nirsoft, this utility shows all the information known about the battery in Windows. Especially, the "charge/discharge rate" while the charger is connected might be the value that you're looking for.

enter image description here

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  • Sounds like "charge/discharge rate" is less than what the power supply actually outputs when the laptop is running.
    – Bergi
    Nov 28 '21 at 22:49
  • 2
    @Suncatcher: Voltage here is batter voltage, not USB-C voltage. I don't expect the USB-C PD voltage to be the same; the laptop will almost certainly have an internal voltage regulator and battery charger that converts from the PD voltage over the wire to a charge current for the battery. (Typically by regulating for a specific charge current, whatever voltage is necessary to achieve that. But USB-C PD works by asking for a voltage, so you definitely can't just connect that across battery terminals without risking a fire from a high current in or out of the battery.) Nov 29 '21 at 5:11
  • 2
    Is the point of this answer to look at the battery charge rate and assume the laptop is pulling the max 3A at some voltage, then solve for voltage? (After assuming the laptop is drawing some watts itself, so CPU/screen power + charge rate = V * I, where I = 3 amps? Nov 29 '21 at 5:13
  • These are the right measurements at the wrong part of the circuit.
    – Ben Voigt
    Nov 29 '21 at 22:06
  • CPU/screen power + charge rate = V * I so without knowing CPU/screen power we are out of the luck?
    – Suncatcher
    Nov 30 '21 at 9:46
9

I use a USB-C breakout board and a voltmeter. If you have Windows though, harrymc's answer is easier.

USB-C Breakout from PMDWay, SKU 15182003

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  • For current as well? - do you need to add jumpers to the breakout board for normal operation? Or are the two pins for each signal line only for convenience? Nov 29 '21 at 17:41
  • @PeterMortensen You don't need jumpers, and there is only 1 connection on the board per pin of USB C (USB has 24 pins receptacle+ shield (22 pins on the plug))
    – Ferrybig
    Nov 29 '21 at 18:28
  • @PeterMortensen, thank you for the edit. This one is not useful for current without modification.
    – rsaxvc
    Nov 29 '21 at 18:31
1

Sounds like you need a USB-C PD power (voltage and current) monitor, although it, rather unfortunately, has a USB-A output:

USB C Power Delivery Voltage Current Monitor and DC Output

A - Power input via USB C plug- connects to supply USB C socket such as power bank

A1 - Power input via USC C socket - connects to USB C cable from power supply

B - Status LED - lights when communcation of Power Delivery protocol is successful between monitor board and power supply under test

C - Digital display. Shows voltage when connected to power supply and no load connected; alternates between voltage and current when load connected at D

D - USB output - connect load here

E - voltage down - press to reduce power delivery test voltage

F - voltage up - press to increase power delivery test voltage

Simply connect to the USB C power supply or battery pack, then use the two buttons on the monitor to select the trigger voltage - 5, 9, 12, 15 or 20V DC. This tells the supply under test to up the voltage output which can be monitored using the numerical LED display.

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