Ask HN: How to navigate USB-C charging hell | Hacker News Reader

Ask HN: How to navigate USB-C charging hell

15 pointskuon19 comments

I realize this topic has been discussed numerous times, but after some research I found about 50 different "theories" on how it is supposed to work.

As a developer and electronic engineer, it deeply frustrate me to have no good understanding of it. I am quite sure that the actual protocol and electrical details are simple, but because everybody comes with their own theory, navigating google results is really hard.

Long story short, I built a new threadripper workstation, and none of the gazillion of USB port will charge my One Plus 5T phone.

I tried all the the A-C ports with different cables (aren't A port just 4 contacts? what can be in the cable, resistors?...). I also tried C-C and it doesn't charge either.

So, two questions:

- Is there a good, technically precise and right explanation of the whole situation? I tried reading the USB standard, but it would take days to extract a proper understanding of it.

- In there an adapter or something I can use on USB-C port of my workstation to provide a "charge port" for my phone which seems to require some voodoo magic to charge?

I am posting on HN because it has a lot of visibility, and I hope this post might become a beacon of hope in the USB situation (this part is very pretentious, but HN did surprise me quite many times).

There's classic USB (5V @ 0.5A) which is supported by every USB port and USB Power Delivery (USB-PD) which can negotiate power up to 240W. Your phone may require PD to charge but none of the ports on your PC provide PD thus it doesn't charge. USB-PD used to be really expensive and now it's still expensive so maybe only Apple supports outgoing PD from their computers.

Then there's proprietary charging protocols like Qualcomm Quick Charge that I hope are being phased out.

Later versions of Qualcomm quick charge are compatible with USB-PD and USB-PD-With-PPS respectively. PPS is programmable power supply which some phones like Samsung need for ultra fast charging.

My motherboard port are USB 3.2 which should support USB PD. But it is part of the things I cannot get confirmation of.

My phone used to charge fine on my old motherboard.

You should give the motherboard model. There usually are tweaks in the bios for charging that might need to be set.

Asus Pro WS WRX80E-SAGE SE WIFI

BIOS or Software issues? You should try other devices to see if your MB are charging those as well.

It will never fast charge on a OP5T but it should slow charge just fine. Only later OP phones (8 onwards) will medium fast charge on standard USB-PD (15 or 18W not the full 35 or 65W). Eg a laptop charger or Qualcomm QC 3.0 or higher.

But slow charging should work on pretty much anything. Having said that, USB-C has a protocol for active devices connected to each other that agrees which device will deliver power to which. Previous USB standards didn't need that as the cable has different ends and this would determine this based on the port type. USB OTG however started to break this assumption based on plug type but needed a wiring change.

So they made it fully dynamic in USB-C but only if active devices are on both ends. Then they'll negotiate. If an active device just sees 5V from a dumb power supply without any kind of signalling it should always slow charge only. It will assume a dumb USB1 power supply meaning 5V at 500mA so 2.5W charging.

Perhaps this needs some configuration in your case though I've seen every computer charging my oneplus just fine. Try to select USB charging only mode in your oneplus.

A USB condom should also work, it's a cable that only permits the 5V through and nothing else. It's used to avoid public chargers from trying to access your files in secret.

As for technical write-ups hackaday has done some in the past but they're a news site so it's not too easy to find back.

Ah.. OnePlus is a special kind of brand pulling an Apple move when it comes to charging. Only their chargers will do fast charging. Nothing else. I've got an anker charger that supports 60w PD and QC, other brands of phones and devices quick charge no problem, but not my two OnePlus devices - 5 & 9 PRO

P.s over the years I have tested a handful of portable batteries and chargers from other vendors. Nothing seems to work.

> Ah.. OnePlus is a special kind of brand pulling an Apple move when it comes to charging.

> Only their chargers will do fast charging. Nothing else. I've got an anker charger that supports 60w PD and QC, other brands of phones and devices quick charge no problem, but not my two OnePlus devices - 5 & 9 PRO

> P.s over the years I have tested a handful of portable batteries and chargers from other vendors. Nothing seems to work.

It should still normal slow charge though with pretty much anything. If I read the OP correctly it doesn't even do that.

It should also fast charge with Oppo's chargers. And medium-fast charge with regular USB-PD on newer phones like my OP8.

The separate charge tech is annoying but I have to say my 35W charging phone gets a lot less hot than my old Samsung S8 when slow charging. So I do think they have a point.

To correct myself, it stays at the same battery level, so some current must be flowing. I have not tried for extended period of times (> 2hour). The thing is, on the one plus charger it goes to 100% in that time. I will keep it plugged for the night and see where it goes.

So there is no way to fast charge it, even with some adapter? That's disappointing.

Edit: I realize it was charging was faster (but not as fast as official adapter) with my older motherboard, so I guess there is still another issue here.

Your OnePlus 5T have an USB 2.0 with USB-C port which by default should be charging with minimum of 2.5W. A full charge from zero to full would take 6 hours. This is likely what you are seeing now.

Your old MB was likely charging at default USB-C port which "should" have a minimum of 7.5W charging, i.e 3x of what you are getting. My guess is that OnePlus is looking for USB-PD 1.0 but your newer Motherboard only support USB-PD 2.0 and 3.0. So it somehow dropped back to the minimum USB2.0 charging standard.

Again you should look at BIOS settings to see if there are any relevant options.

But does the phone say "charging"? This is the indicator of slow charging (as opposed to fast charging, warp charging or whatever buzzwords they come up with).

Regular charging is only 2.5W so it is technically possible for the phone to use as much as that while you keep the screen on and run a heavy app. Leading to what you describe, the battery never reaching 100%. It will of course also require hours to charge at that speed. Check your battery graph. If it stabilizes there may be a background app using a ton of power.

But yeah fast charging a 5T is never going to work without its own charger. Only the latest OP models can do that and even then not as fast as they can with their own charger.

If you want this get another brand next time. Although most brands are now moving away from standard USB-PD for everything and require USB-PD with PPS which allows fast and fine voltage adjustments. USB-PD has only a few set voltages and needs an interruption and slow negotiation for every change in voltage. PPS can do fine adjustment on the fly.

The reason that fine adjustments are needed for ultra-high charging speeds is to remove the bulky and heat-generating high-power DC-DC converter from the phone itself and move it to the charger where heat and space are not so much of an issue. It's basically what oneplus has done for years but now in a standard way (and not compatible with OP's implementation)

No laptop charger or port I know of supports this USB-PD-With-PPS right now. It'll still charge medium fast though. 18W or so (which is not actually a lot in most modern phones that have speeds of up to 100W sometimes)

After the night, it went from 11% to 15%, ans it says "charging". So I guess I wasn't right when I say it didn't charge.

Yeah check then if there an app keeping the phone awake. I bet that's it.

Would using one of those little USB charge monitors (like this one: https://amzn.to/310fIou) help? it should show you what the charge is coming in and out of the mobo and different ports... I have used one to test cables, etc... I think thats the one i actually have...

Must read the V and I output at end by use a MM

Then side it by side with the rating data of the wanted charged device (on its manual)

basically to work the charger rating must be greater than the device's

> Long story short, I built a new threadripper workstation, and none of the gazillion of USB port will charge my One Plus 5T phone.

Sounds to me like your PC is busted.

Sounds more like the phone.

the key points being good, and technically precise.

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