How much power does each USB-C port provide (2021 Model Y)

[jcanoe]

thats the million-dollar question!

Hoping someone can load up 4 devices and let us know what the power-sharing looks like between using both front ports.. both rear ports.. and all 4 ports simultaneously. I'd imagine most people buying the Model Y have a family of 3-5 passengers.. and all of these USB charging ports get regularly used. Often simultaneously.

There should be a USB-C dummy load plug.

 

[Tha_Ape]

There should be a USB-C dummy load plug.

A USB resistive heater would stress something pretty fierce

 

[TomB985]

I just tried with my iPad and a big power bank. Looks like it steps down to 8v when two are connected, but it was still pushing over 20w to each. Below are photos of (1) both plugged in, (2) the iPad only, and (3) the big power bank.

 

[kishkaru]

Yes!! I would be very interested if you would test loading each port to see what happens! As generally speaking on a long road trip.. everyone in the car tends to have their personal device plugged in!!


Many.. many thanks in advance!!!

Is the power per port halved when both front ports or both rear ports are in use? What happens when charging 2 phones and 2 iPads or similar complement of 4 devices using the USB ports?

thats the million-dollar question!

Hoping someone can load up 4 devices and let us know what the power-sharing looks like between using both front ports.. both rear ports.. and all 4 ports simultaneously. I'd imagine most people buying the Model Y have a family of 3-5 passengers.. and all of these USB charging ports get regularly used. Often simultaneously.

I finally got 2 USB PD testers and electronic loads! Here you go guys, testing the 2nd row USB-C ports concurrently:



This is with 2 loads simultaneously pulling 9V/3A = 27W each. The car had no problem powering both loads at 27W, for a total of 54W. Not even a little bit of voltage drop from the ports to indicate any kind of power overload at the car side.

So those saying they're unable to charge 2 iPads simultaneously doesn't make any sense. Unless those iPads need more than 27W each.
Even if that's the case, the 2021+ cars have 12V/3A rail, so that's 36W per port. That's 72W total in the 2nd row. It should be plenty to charge any device, except a laptop (which would likely require 20V rail). And maybe an iPad Pro which @TomB985 says required 40W peak.

It's a shame that Tesla doesn't document any of this. It would save us all the guess work, but testing it ourselves is fun too!

 

[TomB985]

Thanks, @kishkaru; very useful post. It’s great to see they’re not limited when charging more than one thing.

It’s worth mentioning that none of these things require peak current. My iPad Pro will charge from a little 5w iPhone charger if I use the right cable. It would take 9 hours with the screen off, though, and wouldn’t’ be able to keep up with continued use.

These charging speeds are great, though. More than enough to drive my 16” MacBook for all but the most demanding things.

 

[Daekwan]

I finally got 2 USB PD testers and electronic loads! Here you go guys, testing the 2nd row USB-C ports concurrently:



This is with 2 loads simultaneously pulling 9V/3A = 27W each. The car had no problem powering both loads at 27W, for a total of 54W. Not even a little bit of voltage drop from the ports to indicate any kind of power overload at the car side.

So those saying they're unable to charge 2 iPads simultaneously doesn't make any sense. Unless those iPads need more than 27W each.
Even if that's the case, the 2021+ cars have 12V/3A rail, so that's 36W per port. That's 72W total in the 2nd row. It should be plenty to charge any device, except a laptop (which would likely require 20V rail). And maybe an iPad Pro which @TomB985 says required 40W peak.

It's a shame that Tesla doesn't document any of this. It would save us all the guess work, but testing it ourselves is fun too!

Incredibly helpful post.

Before I first created this thread.. I searched Google, Youtube, Reddit, and this entire forum to see if someone had provided this information. It is amazing you are basically the first person to answer this question that Im aware of. Out of all the other thousands of posts about which PPF should I get or which ceramic coating works best.. it's crazy that almost no one (including Tesla) has put power meters on the USB-C ports and told us what the actual load is when using a bunch of devices.

It also directly counters people who said "read the manual". As the manual is flat-out wrong.. as it claims the USB-C ports only provide 15W of power. This car is able to provide significantly more for each port.. and as you have tested keep that high power output even when several devices are plugged in.

This is exactly what the manual states: "The USB ports can output power up to approximately 15W (which may vary depending on vehicle manufacture date)." Tesla should correct this information.. after confirming the power output tests you have already conducted. Furthermore, power output should be specified based on which model year. I imagine when the Model Y was originally launched in 2020.. the original USB-A port probably output a max of 15W. That number has apparently increased to 27W with the introduction of USB-C after the 2021 console refresh. And now the number is all the way up to a max of 36W on Model Y's built from 2022 through present production.

 

[jcanoe]

The 15W maximum output for the USB-C port assumes 5V and 3 amps (5 X 3). If your device can operate at 9V the maximum output is 9V X 3A for 27W.

 

[Daekwan]

The 15W maximum output for the USB-C port assumes 5V and 3 amps (5 X 3). If your device can operate at 9V the maximum output is 9V X 3A for 27W.

The manual should state that.

To be clear.. 15W is generally the max output of USB-A with consumer devices. This is why it's my belief that the "15W max" is simply old information referring to when the Model Y shipped with USB-A ports in 2020. If you read the entire paragraph above the section in the manual where it says 15W is the max power available.. it refers to the USB ports as generic USB. It doesn't specific USB-A or USB-C.

My guess is Tesla is well aware of this.. they just haven't updated the manual to be specific about the max amount of power available with USB-C.

 

[kishkaru]

Im the OP. If you read my post at the top, you will see me alluding to this. I believe its easiest explained this way:

• 2020 MY & early 2021: 15W max per port for the USB-A, 27W max per port for the USB-C (old console)
• Late 2021: 27W max per port for all the 4 USB-C (new console)
• 2022 - Current: 36W max per port for the 2 front USB-C, 27W max per port for the 2 rear USB-C

Sorry, I just want to clarify one thing I said incorrectly in my post above:

Every Model Y has 5V/9V (27W) max in the 2nd row, going back to 2020. The 2nd row (and 3rd row?) power outputs have not been updated over the years.
The 12V rail addition (36W) seems to be only for the front 2 USB-C ports in the newer model years.
I don't have a newer car so I personally cannot confirm this, but that seems to be the reasonable conclusion based on the photos by @TomB985 and @FultonMDUSA .

A family member has a 2022 MY (mid-year) with the 2 front USB-C ports. I guess I'll borrow their car for some "testing" . Stay tuned!

 

[kishkaru]

It’s worth mentioning that none of these things require peak current. My iPad Pro will charge from a little 5w iPhone charger if I use the right cable. It would take 9 hours with the screen off, though, and wouldn’t’ be able to keep up with continued use.

These charging speeds are great, though. More than enough to drive my 16” MacBook for all but the most demanding things.

Oh that's so interesting. I didn't know Macbooks can charge at lower voltages than 20V! And indeed, I just plugged in my Macbook Pro to the 2nd row USB-C ports and it happily started charging at 9V/3A (27W). I've been buying 20V-capable USB-PD power supplies this whole time, to charge my laptop

I don't think the same can be said about Windows laptops. Many of the Lenovos I've owned in the past required 20V via USB-C. Otherwise it refused to charge.
For those devices that require 20V, I recommend the Phillips 12V accessory socket adapter to USB-PD power supply. 5V/9V/12V/15V/20V at 3A.
It works great for me to charge my laptops. And even for Macbooks, it's still beneficial to charge at the higher voltage for efficiency (and faster charge speeds!).

For sure though, don't use 120V AC inverters via the 12V accessory socket. 12V DC -> 120V AC -> 20V DC is very inefficient. Direct DC-DC converters are the way to go.

 

[Daekwan]

Oh that's so interesting. I didn't know Macbooks can charge at lower voltages than 20V! And indeed, I just plugged in my Macbook Pro to the 2nd row USB-C ports and it happily started charging at 9V/3A (27W). I've been buying 20V-capable USB-PD power supplies this whole time, to charge my laptop

I don't think the same can be said about Windows laptops. Many of the Lenovos I've owned in the past required 20V via USB-C. Otherwise it refused to charge.
For those devices that require 20V, I recommend the Phillips 12V accessory socket adapter to USB-PD power supply. 5V/9V/12V/15V/20V at 3A.
It works great for me to charge my laptops. And even for Macbooks, it's still beneficial to charge at the higher voltage for efficiency (and faster charge speeds!).

For sure though, don't use 120V AC inverters via the 12V accessory socket. 12V DC -> 120V AC -> 20V DC is very inefficient. Direct DC-DC converters are the way to go.

For an entire year I charged my 2020 M1 MacBook Air using the 2.4A port in my old Anker 5 port USB-A 5V charger. Means it was charging at max of 12W and it did just fine. Used some cheap $1 USB-A to USB-C cables.

Main purpose for doing it is that you could travel with that one Anker 5 port 60W USB-A Charger.. and charge my MacBook Air, iPhone, iPad, Apple Watch and one more device like my Sony Bluetooth noise cancelling headphones or a pocket travel router.. all using a single wall outlet. I’ve probably carried that thing around for 8 years now.

Looked like this.. but 5 ports:

 

[kishkaru]

Over the weekend, I had a chance to borrow and test a family member's 2022 Model Y. There are some interesting results after testing.

First the good news:
Yes, the front 2 USB-C ports are now 12V capable, at up to 3A.

Front USB-C ports:
USB-PD 3.0
5V/3A
9V/3A
12V/3A



And it's able to supply 12V/3A (36W) to a load with no issues. The voltage drop is caused by a long USB-C cable I used:




And now for the bad news:
As soon as a second USB-C load is plugged in to the second USB-C port up front, the 12V rail on each disappears:

Front USB-C ports (2 concurrent loads):
USB-PD 3.0
5V/3A
9V/3A



Looks like the front USB-PD power supply in the car is not able to supply two loads at 12V/3A (36W) concurrently.
However, it is still able to power two devices at 9V/3A (27W) concurrently, which is identical to the rear ports power rating:




And for the final test, I tried concurrently loading one front USB-C and one rear USB-C at their maximum power rating.
The front USB-C was able to power a load at 12V/3A (36W) while the rear was able to power at 9V/3A (27W), for a total of 63W.
So looks like the front USB-C and rear USB-C ports are powered by two independent USB-PD power supplies in the car, so they do not affect each other.

Unfortunately, I currently only have 2 USB-PD testers and USB loads. But if I had 4 of each, it would be interesting to see if the car can provide 4x (9V/3A = 27W) for a total of 108W from all 4 ports!





My conclusion from all this:

1. If you have a high power device (laptop, iPad Pro, etc) that require the 12V rail (12V/3A = 36W), plug it into one of the front USB-C ports, and keep the second front port empty.
2. If you need to power another device while the above device is charging, use the two rear USB-C ports first, which provide up to 27W (9V/3A) each.
3. If and only if you have to power a 4th device, then use the second USB-C port up front, which will cause the voltage to be limited to 9V/3A max (27W) for each front USB-C port.

If your device only charges at 5V (15W) or 9V (27W), then don't worry about any of this. Just plug it into any of the 4 USB-C ports in the car and it will charge at max speed, concurrently.

 

[ElectricAnt54]

I have an oddball case. I replaced my 2022 model y front usb-c module (power only) with a TParts (third party) module which supports power & data. I might have to get one of these gizmos to test the third party product. That being said, I have had no issues powering a 5x3 raspberry pi and usb-c stick playing music. Maybe I can get a program on my pi to tell me the power info Since the pi screen appears in tesla web browser via open source “tesla android” project.

 

[Audiotronics]

Wow thank you so much everyone here in the community for providing me with this super important information! I am scheduled for Wednesday to pick up my 2023 MYP. I sold my old car an out a month ago and have been researching all the interior accessories for a month now. I am planning on installing a uniden radar detector and I bought an rj11- usb c cable that requires usb-c-pd ports of at least 9v. And 5watts to power it. I now can confirm that this will work thanks to this post! I have searched for days trying to find this data annd finally found a small link in google leading here. and now I know I haven’t wasted any money by trying to buy parts before I even have the car!
Anyways if anyone need to install a radar detector with a usb c cable it will work ! I didn’t want to have to use the cigarette lighter socket and have a blue from the arm rest to the window

 

[Audiotronics]

Wow thank you so much everyone here in the community for providing me with this super important information! I am scheduled for Wednesday to pick up my 2023 MYP. I sold my old car an out a month ago and have been researching all the interior accessories for a month now. I am planning on installing a uniden radar detector and I bought an rj11- usb c cable that requires usb-c-pd ports of at least 9v. And 5watts to power it. I now can confirm that this will work thanks to this post! I have searched for days trying to find this data annd finally found a small link in google leading here. and now I know I haven’t wasted any money by trying to buy parts before I even have the car!
Anyways if anyone need to install a radar detector with a usb c cable it will work ! I didn’t want to have to use the cigarette lighter socket and have a blue from the arm rest to the window

**Cable**from the arm rest to the windshield.

 

[Evee]

anyone do this for a new MS?

 

[Evee]

Can confirm the same setup for the new msx.

 

[jonny2x4]

Reading this thread I would expect my Pixel 6 Pro to charge at max speed on the front port but on ampere I'm only seeing around 960mA. Are apps this inaccurate? My phone was at 40%

 

[TomB985]

Reading this thread I would expect my Pixel 6 Pro to charge at max speed on the front port but on ampere I'm only seeing around 960mA. Are apps this inaccurate? My phone was at 40%

Which app are you using?

I can try this morning on my Pixel 7 if I know which app to try.

 

[jonny2x4]

Which app are you using?

I can try this morning on my Pixel 7 if I know which app to try.

Ampere