USB power information

The only stuff I have tested from XIAOMI is a AA/AAA charger/power bank and a power strip.

Would be great if you could test this next time: Xiaomi QC 3

Tad off-topic little question for you fellow electronic experts…

I have an ooold (30+ years at this point) electronic parts toolbox, with, among other stuff, a nice bunch of various brands electrolitic capacitors (Anodia, Bianchi, Trobo, …). I was wondering if it is worth giving that stuff a try (LoL!), because there are plenty of 25+V rated units. Oh! Well, I also have an old computer motherboard with a nice pack of 10-16V units which I could settle 2S2P and they're much likely to be in operative condition. O:)

Cheers ^:)

Please repost the request here: Review request for HKJ [USB Power Devices] That is where I look when I need more to test.

Probably not, newer capacitors are smaller with better specifications.
If you want to try them check for leakage current first, they may need to be connected to a voltage for some time first (Leakage current increase when a electrolytic capacitor is in storage, but will (slowly) go down again when voltage is applied).
If leakage current is fine, you also need to check ESR (Depends on application how significant it is).

How can i measure the max/peak current an usb device is using so i can pick the correct rated usb adaptor.

Any help is appreciated.

Thanks

John.

While some tablets may pull a good amount, I'd say it is quite unlikely to go beyond 10W (except maybe when playing ultra-heavy 3D games and stuff like that). Even with the “torch” on, I've rarely seen my XT1032 phone pulling more than 4W (I don't play heavy games).

Getting a good “charger” is inexpensive too: NILLKIN 5V 2A Travel Charger Adapter - EU PLUG BLACK @ GearBest

Reviewed by HKJ and good up to 3A: Nillkin AC Adapter 2.0A @ lygte-info.dk

Cheers ^:)

P.S.: sorry, didn't answered your question directly. For an Android device, the app “Battery Monitor Widget” will answer your power draw inquiry accurately.

I ordered an windows mini pc that comes with an 5v 3a adapter, I want to find out the max current it uses when running the cpu/gpu at max to see if any of my power banks would work with it.

Thanks

John.

To really measure peak you need to put a ammeter with peak readout in series with the current in the usb cable.
I can easily do it because I have made usb breakout cables and have 5 volt lab power supplies and DMM’s with peak reading.

Without all that equipment the easiest way is to measure the current with an usb meter, but it will not be that precise and it will not be the peak.

Most of the time there is no real reason to measure the current, just use a power supply that can deliver 2.4A

Do you mean clamp meter?, I have an Uni-T UT210E but i dont know if it has peak.

John.

Clampmeter is the best, a normal wired meter on 10A range can be used, especially if you adjust the power supply to 5.2V (A lot of equipment will adjust current draw depending on voltage).

The break-out cable above will not work with phones, they check the coding on the data lines.

Hi, HKJ.

I’m impressed by your website ! Great job.
I’ve read you’re using Arduino and resistors to control Quick Charge chargers, I guess in a similar way to QC2Control - GitHub - septillion-git/QC2Control: Set the voltage of a Quick Charge 2.0 source via the Arduino.
I’d be interested in implementing a similar project for Quick Charge 3.0, particularly because it has a “continuous mode” where voltage can be changed by 200mV increments, but I’m can’t seem to find a specification. The closer I got is the state machine on page 10 of the NCP4371 chip datasheet - http://www.onsemi.com/pub/Collateral/NCP4371-D.PDF
Would you by chance have a specification for Quick Charge 3.0 ? Or did you reverse engineer it ?
Any hint is welcome…

Kind regards,

Vicne

I used a datasheet and it looks like that datasheet contains anything you need to implement it.

@hkj
Any chance you do a follow post to cover the new stuff?

There is a short German article about recent Quickcharge stuff and USB PD.

https://mobil.teltarif.de/quick-charge-usb-pd-schnellladesysteme/news/76410.html

I do not have enough new information for a follow up article.

Thank you for your answer hkj

I found two interesting web pages in German about

• USB Power Delivery PD 2.0 and PD 3.0 Home - InfoTip and

• USB 3.1 Gen2 (the typ-C stuff)
https://kompendium.infotip.de/usb_3.1_gen_2_usb_typ-c_verbinder.html

Sorry I didn’t found sth. about USB 3.2

I don’t know how good your German is or if Google translate works well with the pages.

That power delivery and USB Type-C seems a bit complicated.

Notes from my resent search for USB-C cables

- for a search “USB-C” is more helpful than “Type-C”

- To find cables with full 5 ampere use “USB-C PD 5A” or “PD 5A”

- some 5 ampere cables have a purple core in the USB-C plug to distinguish from a 3A variant

  • 60W cable is 3A, a 100W cable is 5V

There are some 5A cables with 0.5, 1.0 and 1.5 meters:
https://www.delock.de/produkte/S_85814/merkmale.html

https://www.delock.de/produkte/G_1764_USB-Type-C—Stecker—-USB-Type-C—Stecker.html

lindy.de/0-5m-USB-3-1-Typ-C-Kabel-5A-PD-Anthra-Line.htm
lindy.de/0-5m-USB-3-1-Typ-A-an-C-Kabel-5A-PD-Anthra-Line.htm
https://www.lindy.de/websale8/?Ctx=%257bver%252f8%252fver%257d%257bst%252f40d%252fst%257d%257bcmd%252f0%252fcmd%257d%257bm%252fwebsale%252fm%257d%257bs%252fld0101%252fs%257d%257bl%252fld0101%252fl%257d%257bmi%252f800503%252fmi%257d%257btpl%252fws%255fsearch%252ehtm%252ftpl%257d%257bmd5%252f74cfec6d2130f9912d250872f009e8d7%252fmd5%257d&tpl=ws_search.htm&search_input=PD+5A

Check out this table:

Hi SB, please consider to stick this thread. Very helpful for us

[Clemence]

I lived through all of this too. I never could remember the rankings of Super vs High vs Full speed… At least when they rev’d SATA, it was I, II, III.

Posting this here since I figured OP or someone else might know the answer.

I’m considering buying Apple’s 87W USB-C power supply (test/teardown) for my non-Apple notebook.

However, I noticed that it’s spec’ed at 20.2v instead of 20v.

1. Does 20.2v violate the USB-PD spec?
2. Could using this power supply with a device that expects 20v USB-C charging cause component damage over the long term?

1. No, it doesn’t.
2. No, as manufacturers usually include a tolerance of about 5-10% on voltage, so it should not be a problem. 0,2V is nothing.