Thunderbolt 3 device and charging pass through.

tom_sellek

macrumors newbie
Original poster
Jan 16, 2019
3
0
Is it possible to use 1 port on my mac to connect to a thunderbolt device and use it to take a power charge from a standard power supply. I am hoping for some gizmo that gives me 2 usb-c sockets, one to plug the device into and another to plug my charger into.
 

gwerhart0800

macrumors 6502
Mar 15, 2008
434
14
Loveland, CO
Is it possible to use 1 port on my mac to connect to a thunderbolt device and use it to take a power charge from a standard power supply. I am hoping for some gizmo that gives me 2 usb-c sockets, one to plug the device into and another to plug my charger into.
Look at the Thunderbolt 3 docks from vendors like OWC. In this case, the dock has it's own power supply, but will change the Mac when it is plugged in as well as provide ports. Not a portable solution, but it does what you asked about. (There are other vendors with similar products, this is not an endorsement of OWC, so look around.)

https://www.owcdigital.com/products/thunderbolt-3-dock-14-port

The other direction, if you don't need true Thunderbolt 3 speeds is a USB-C dock. There are a bunch of those on the market and some have a power pass through. The only tricky part is finding one that can handle the wattage. I have a 2018 15" MacBook Pro and it requires ~87 watts, but many of the USB-C docks are limited to 60 watts pass through. So, check the wattage requirements before buying anything.

I have several of these:

https://www.amazon.com/gp/product/B07H982VWX/ref=ppx_yo_dt_b_asin_title_o07__o00_s00?ie=UTF8&psc=1

But I have to plug the power in separately because they are limited to 60 watts in pass through mode.
 

tom_sellek

macrumors newbie
Original poster
Jan 16, 2019
3
0
Unfortunately I need true thunderbolt as I'm using the Apple thunderbolt 3 => 2 adaptor to connect to the thunderbolt => firewire adaptor to connect to a firewire audio interface! (hopefully I'll upgrade said interface to the thunderbolt 3 version this year). I have looked into the docking stations and did in fact buy (and return) the very impressive Caldigit T3. My only issue with these devices is the huge heavy power bricks they ship with.

My requirements are a bit niche as it's to go into a flight case for an onstage setup so size / weight is paramount.

Reading this interesting article https://www.akitio.com/blog/articles/60w-power-delivery-macbook-pro if the devices have their own power supply (which mine does) 60 watt is sufficient to power the (87w) laptop on it's own. It wouldn't charge as quick but crucially it wouldn't discharge.

That USB-C dock you mention is exactly the size product I wish existed, I can't see any reason why it couldn't be made.

I've given up on my search, I don't think such a product exists unfortunately. I will settle for running 2 cables to my mac, 1 for power, 1 for the firewire device.
 

chrfr

macrumors G3
Jul 11, 2009
8,289
2,589
Unfortunately I need true thunderbolt as I'm using the Apple thunderbolt 3 => 2 adaptor to connect to the thunderbolt => firewire adaptor to connect to a firewire audio interface! (hopefully I'll upgrade said interface to the thunderbolt 3 version this year). I have looked into the docking stations and did in fact buy (and return) the very impressive Caldigit T3. My only issue with these devices is the huge heavy power bricks they ship with.

My requirements are a bit niche as it's to go into a flight case for an onstage setup so size / weight is paramount.

Reading this interesting article https://www.akitio.com/blog/articles/60w-power-delivery-macbook-pro if the devices have their own power supply (which mine does) 60 watt is sufficient to power the (87w) laptop on it's own. It wouldn't charge as quick but crucially it wouldn't discharge.

That USB-C dock you mention is exactly the size product I wish existed, I can't see any reason why it couldn't be made.

I've given up on my search, I don't think such a product exists unfortunately. I will settle for running 2 cables to my mac, 1 for power, 1 for the firewire device.
The 15" MacBook Pro could certainly discharge if run from a 60W power supply under heavy load. The computer can also discharge from the 87W power supply if the CPU/GPU load is high enough.
 

gwerhart0800

macrumors 6502
Mar 15, 2008
434
14
Loveland, CO
I've given up on my search, I don't think such a product exists unfortunately. I will settle for running 2 cables to my mac, 1 for power, 1 for the firewire device.
I ended up with the same compromise. I can't justify spending $200 or more on a true Thunderbolt 3 dock that would give me a single cable solution. On the other hand, the USB-C docks are relatively cheap, so I am now up to 4 of those (3 in office locations and one for mobile/on-the-road use). I am also happy that I could get 3rd party chargers for about 60% of what apple charges and they are working out just fine. The unhappy part is that I had 3 Thunderbolt 2 docks and a zillion power adaptors for my 2015 MBP ... all are surplussed at the moment. Trying to find someone local who wants them, rather than sending them to recycling.

There are times where the form-over-function design really pushes me away from Apple, but I need a Unix type laptop for the type of work I do and it is the only option that works with my company VPN, etc.
 

tom_sellek

macrumors newbie
Original poster
Jan 16, 2019
3
0
I ended up with the same compromise. I can't justify spending $200 or more on a true Thunderbolt 3 dock that would give me a single cable solution. On the other hand, the USB-C docks are relatively cheap, so I am now up to 4 of those (3 in office locations and one for mobile/on-the-road use). I am also happy that I could get 3rd party chargers for about 60% of what apple charges and they are working out just fine. The unhappy part is that I had 3 Thunderbolt 2 docks and a zillion power adaptors for my 2015 MBP ... all are surplussed at the moment. Trying to find someone local who wants them, rather than sending them to recycling.

There are times where the form-over-function design really pushes me away from Apple, but I need a Unix type laptop for the type of work I do and it is the only option that works with my company VPN, etc.
I hear you on the wasted TB2 tech and power supplies. I purchased this https://www.amazon.com/ELECJET-Anywatt-Magsafe-Converter-Compatible/dp/B075RZJS2Z/ref=cm_cr_arp_d_product_top?ie=UTF8 so I could at least reuse the power supply from my Apple Thunderbolt display.
 

dwig

macrumors 6502a
Jan 4, 2015
659
242
Key West FL
The 15" MacBook Pro could certainly discharge if run from a 60W power supply under heavy load. The computer can also discharge from the 87W power supply if the CPU/GPU load is high enough.
@OP: also keep iin mind that the wattage spec'd by the hubs/docks is the maximum supplied and not a guaranteed amount. In order to get 60w out to the notebook, the USB-PD power supply must be larger than 60w (the max official USB-IF spec for PD is 100w) because some power is sypnoned off to run the hub/doc and to power any attached devices that may need it.

There are a few more portable TB3 hubs, but not nearly as many or varied as the USB-3.1gen1/2 types. This is largely due to the added cost of adding the necessacy circuitry & cableing that TB3 requires.