Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

What's the wattage for the 2 rear USB-C ports?

IIRC, it goes something like this.

Type A style port (like we see on a USB Flash drive)
USB 1.0 = 5V, 0.1A = 0.5W max
USB 2.0 = 5V, 0.5A = 2.5W max
USB 3.0 = 5V, 0.9A = 4.5W max

There is also the battery charging spec which can do 7.5W (5V, 1.5A), not sure on the connector, assume it is type A

Type C style connector (like in rear of MY, has extra connections to deliver more power)

USB 3.1 = default 5V, 2A = 10W = Profile 1 of Power Delivery spec, without any negotiation.
This is your starter power that can be used to bring the device alive so it can then negotiate for even more power if needed.

Once the plugged in device is up and running on 10W, it can then use PD and negotiation for more, as long USB hub in the MY can supply it. The voltage and current will be varied as part of the negotiation, to go from defaults of 10W using 5V. Quality cables that are not too long is very important, to get the higher power stuff working correctly.

Profile 2 = 18W max = 12V, 1.5A
Profile 3 = 36W max = 12V, 3A
Profile 4 = 60W max = 20V, 3A
Profile 5 = 100W max = 20V, 5A

Above are maximums, so if not using the max of that profile, the V and A can vary to something less as per the spec.

No idea how much power the MY rear USB can supply, have never seen that published, did I miss it? But if the laptop using 2 ports was able to get 25.5W then there has to be some PD going on since max without PD from 2 ports = 10W + 10W = 20W
 
Phone fast charge is limited to 20watts, anything more will be disregarded. Advantage is if you have a laptop which can charge at much higher speeds although 36w is not all the great for a laptop.
This is a complicated subject that I am not an expert at. However, I know that there are different voltage / amp combinations and not all devices are capable of receiving all combinations. It could be that Tesla 36watt power is offered in a combo that android phone is not compatible. My apple laptop loves the 36w though!
 
It does get complex because Apple based products need to talk in PD format or they cannot properly adjust voltage/charge rate and will then default to standard slow rate. Same goes with Android which uses another protocol that I am not familiar with. Not sure what protocol Tesla has used.

Just avoid Apple products. I have 0. Beside Apple doesn't want to play nicely with USBC in Europe.
 

tm1v2

Active Member
Oct 18, 2021
1,421
1,033
USA
Apple and Google are probably the two companies most keen on USB-C and USB PD, there's not really much difference there except iPhones still needing a USB to Lightning adapter cable, and some Android phone makers are less committed to USB PD than Google themselves.

Nice info there @Ataman about the front ports going up to 36W for 2022 cars! Consider me very slightly jealous. :) My 2021 Model 3 is 27W max on all 4 USB-C ports (2021 Model Y is the same I assume). I'm actually a little surprised that 36W would be the max though, I would think they might as well support 45W if they're supporting 15V and maybe 20V profiles. (Or did they add 12V at 3A for some reason? I believe 12V is outdated now...most new devices and chargers don't support it anymore I believe.)

As for powering and charging a laptop it really varies. 27W is plenty to keep anything ultra portable running and slowly charging. On the other end of the spectrum, 27W or even 36W won't be enough to keep a beefy high powered discrete GPU gaming laptop going, at least not if you're actually putting that power to use.
 
Apple and Google are probably the two companies most keen on USB-C and USB PD, there's not really much difference there except iPhones still needing a USB to Lightning adapter cable, and some Android phone makers are less committed to USB PD than Google themselves.

Nice info there @Ataman about the front ports going up to 36W for 2022 cars! Consider me very slightly jealous. :) My 2021 Model 3 is 27W max on all 4 USB-C ports (2021 Model Y is the same I assume). I'm actually a little surprised that 36W would be the max though, I would think they might as well support 45W if they're supporting 15V and maybe 20V profiles. (Or did they add 12V at 3A for some reason? I believe 12V is outdated now...most new devices and chargers don't support it anymore I believe.)

As for powering and charging a laptop it really varies. 27W is plenty to keep anything ultra portable running and slowly charging. On the other end of the spectrum, 27W or even 36W won't be enough to keep a beefy high powered discrete GPU gaming laptop going, at least not if you're actually putting that power to use.
I do not have a proper measuring device just yet. It is in the mail! I can simply see the power avail from my MacBook Pro which only gives me a wattage. So I am not sure what volt / amp combo I was getting that with.

Totally, even 36W is only half of Apple supplied charger for my laptop but still can charge it overnight followed by long enough usage for travelling purposes.
 
  • Like
Reactions: tm1v2

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top