Thunderbolt 4 Dock power to connected accessory devices

Question

I have a MS Surface Thunderbolt 4 Dock and have connected an external monitor to the Dock. The external monitor works (as expected) when the Thunderbolt 4 is charging my Surface Pro (11th Edition).

However, if you are to limit charging (not always keeping your Surface Pro plugged in) then how would you continue to use the external monitor when my Surface Pro is not plugged into the Thunderbolt 4 Dock? The only solution I had was to disconnect the external monitor cable from the Thunderbolt 4 Dock and then plug the external monitor cable directly into the Surface Pro's USB C connection every time I stopped charging my Surface Pro. If I need to do this then it defeats the purpose of having the Thunderbolt 4 Dock station.

I understand the Surface Pro has Power Management capabilities to help prevent overcharging or pausing the charging process, but the expectation is still at some point the Surface Pro needs to be disconnected from the power source (Thunderbolt 4).

Any suggestions or recommendations is appreciated.

Answer 1

Hello Rodriguez,

Welcome to Microsoft Community.

If the external display you are using does not have a separate power supply, then to make it work properly, it is bound to be connected to the Dock via a USB cable for power support.

But when your Surface connects to the Thunderbolt 4 Dock via the Connect port, the Surface is powered directly through the Thunderbolt 4 Dock.

At this point, the Surface and the external display are powered through the Thunderbolt 4 Dock, and they cannot be separated.

I understand your concern that the Thunderbolt 4 Dock will keep charging the Surface's battery in this state and ultimately reduce battery life. But let me kindly explain to you that your fears are unnecessary.

If the Surface device is fully charged, it will be powered directly by the Thunderbolt 4 Dock, rather than draining the battery and charging at the same time, so there is no overcharging. There are IC chips in the Thunderbolt 4 Dock that monitor the entire charging process and ensure that the battery is not overcharged once it is fully charged.

In addition, the Surface Pro 11 has a smart charging function, which is always active and automatically turns on when the device is detected to be plugged in for a long time or used at high temperatures. This is an automated function that does not require your manual intervention.

Smart charging on Surface - Microsoft Support ****

Smart charging on a new device may not be activated right away, because Surface learns your charging habits and eventually applies them to smart charging. So after using for a period of time, you may inadvertently find that the battery can only be charged to 80%, please rest assured that this is a normal phenomenon, Surface is using the corresponding function to protect the battery.

If you still want some advice on battery care, please allow me to share with you the following support link:

Caring for your Surface battery - Microsoft Support

If you think my reply can answer your questions, please feel free to mark Yes or No to make it easier for other customers to find this more quickly. 

Best Regards,

Mitchell | Microsoft Community Support Specialist

Answer 2

Mitchell,

Thank you for your prompt and detailed response. Greatly appreciated your comments and feel that my question was thoroughly answered.

Paul

Answer 3

Hi Rodriguez,

You're welcome, and if you have further questions about using Microsoft products in the future, feel free to post a new thread here.

Have a good day.

Best Regards,

Mitchell | Microsoft Community Support Specialist