So what exactly makes a usb c cable "worthy" to charge my macbook pro?

iemcj

macrumors 6502
Original poster
Oct 31, 2015
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133
I thought the point of switching to a usb c only laptop would be compatibility but apparently not. My laptop will charge just fine with the supplied cable but nothing else. The usb c cable I charge my gopro with? Nope, it'll just say "not charging" and nothing happens. The usb c cable I use to charge my ninendo switch controller? Nope, it'll just say "not charging" and nothing happens. The usb c cable I use to charge my wifes Galaxy S20 phone? Nope, just says "not charging".

I can understand if it takes more time to charge overnight but I can literally leave it sit there overnight in clamshell mode using no power and it still won't charge unless I'm using the crazy expensive apple charger. What is this?
 

jerryk

macrumors 603
Nov 3, 2011
5,800
2,909
SF Bay Area
That seems very strange.

I charge my S10+ all the time with my 16" MBP's 97W charger and supplied cable. I have also charged my 16" MBP with 45W and 60W 3rd party USB-C chargers and cables. In addition I have charged my phone and iPad with these chargers and cables.

With USB-C the power supply (charger), device, and cable negotiate to set the power (Watts) and the specific voltage and current (amps), Watts = Voltage X Amps, that will be supplied to the device. Each of these has their own limitations that can limit this to control the amount of power sent.

Cables usually have 2 versions. Up to 60W and 100W. Power supplies and devices have their own values based on their capability to deliver and need for power.

BTW, are you sure all these devices need to be charged? That is, they are not at 100% when you tried. If I plug in my freshly charged S10+ to a USB-C charger it does not charge until it drains the battery a bit.
 
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Sanpete

macrumors 68030
Nov 17, 2016
2,596
1,053
Utah
I thought the point of switching to a usb c only laptop would be compatibility but apparently not. My laptop will charge just fine with the supplied cable but nothing else. The usb c cable I charge my gopro with? Nope, it'll just say "not charging" and nothing happens. The usb c cable I use to charge my ninendo switch controller? Nope, it'll just say "not charging" and nothing happens. The usb c cable I use to charge my wifes Galaxy S20 phone? Nope, just says "not charging".

I can understand if it takes more time to charge overnight but I can literally leave it sit there overnight in clamshell mode using no power and it still won't charge unless I'm using the crazy expensive apple charger. What is this?
Those are all low-wattage devices, so the cables may be low wattage too. I've seen USB* cables rated for up to 15W, which probably isn't enough to charge your MBP battery.

Edit: *USB-C.
 
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jerryk

macrumors 603
Nov 3, 2011
5,800
2,909
SF Bay Area
When you get these not charging readings are you using you MacBooks charger with a different cable? That should work. But if you use a small device charger like a phone charger or maybe your switch charger with the USB-C cable that may not work, since the charger cannot put out the minimum power required by the MacBook Pro. I would ensure that whatever USB-C charger you use puts out 45 watts or more.
 

Honza1

macrumors 6502a
Nov 30, 2013
544
204
US
USB-C cables are nightmare, but all of the ones I have (collection of may be 10 or so) will charge my 2017 MBP as fast as power supply allows. Some will be really slow for data transfers (tested with USB-C SSD drive), some are as fast as expected.
But all charge with 60W, may be more. I suggest you replace those which do not work with generic power delivery rated cables. Plenty available everywhere and are not expensive.
Now, finding USB-C cable, which can both do high Power Delivery AND have fast data throughput is bit of challenge and will not be cheap. Only three cables from my collection can do everything - one is Apple and the other two came with USB-C docking stations. I had to label all my USB-C cables with their tested performance.
 

iMacDragon

macrumors 68000
Oct 18, 2008
1,858
349
UK
to charge at 100w usb c cable needs an extra e-mark chip to confirm to devices that the cable is certified for high wattage, otherwise they're limited to 60w.
 

cynics

macrumors G4
Jan 8, 2012
11,554
1,873
I thought the point of switching to a usb c only laptop would be compatibility but apparently not. My laptop will charge just fine with the supplied cable but nothing else. The usb c cable I charge my gopro with? Nope, it'll just say "not charging" and nothing happens. The usb c cable I use to charge my ninendo switch controller? Nope, it'll just say "not charging" and nothing happens. The usb c cable I use to charge my wifes Galaxy S20 phone? Nope, just says "not charging".

I can understand if it takes more time to charge overnight but I can literally leave it sit there overnight in clamshell mode using no power and it still won't charge unless I'm using the crazy expensive apple charger. What is this?
Keep in mind that USB C is the connector/port. USB cables need to be purchased based on your requirements. A maxed out MBP can use more than 100w under a heavy load causing the battery to drop while its plugged in and charging. So a USB 3.1 spec cable for a GoPro to support its 5 watts of charging is not even remotely close...

Things to know..

PD (Power Delivery, specifically 100w in your case) and TB3 (Thunderbolt 3) aren't requirements for the USB C specification so you'll find USB C cables that don't have those features. If you need either of those functions you'll need to specifically look for it when buying, those cables are heavier duty and typically backwards compatible with your other USB C devices.

Thunderbolt 3 has a higher bandwidth so for example if you are ever in the market for USB-C to HDMI look for a TB3 with HDMI 2.0 spec cable and you'll be set for 4k60hz 10bit HDR video.

USB C hubs =/= Thunderbolt 3 hubs. Eventually you might want a USB-C hub for HDMI, ethernet, USB-A, sd card, etc just know that a USB-C hub has a lower bandwidth than TB3 and there might be compromises in the ports specs so that bandwidth can't be exceeded (ex PD 60watt, USB 2.0, 10/100 baset ethernet, 4k30fps max HDMI, etc). Thunderbolt 3 hubs don't typically have an issue but they are very expensive so picking out the correct USB-C for your requirements might be a better choice.
 

simonmet

macrumors 68020
Sep 9, 2012
2,483
3,310
Sydney
I had to label all my USB-C cables with their tested performance.
OP is right to wonder if this is the one-port Nirvana we were all sold!

I guess if you have the right cable(s), it can be. But it isn’t as easy as it was initially made out.
 
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4sallypat

macrumors 6502a
Sep 16, 2016
627
628
So Calif
I have not had any issue charging my new 16" MBP from any other charger - I have used:
  • 29W Apple USB C from my 12" rMB
  • 30W & 60W Chromebook USB-C chargers
  • 61W Apple USB C from my 13" MBP
  • 90W Nekteck Amazon special USB charger
When I travel, I prefer to use the 29W due to the small size of the charger and lighter weight....
 
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