Expansion Bay Shell questions

Framework Laptop 16
1

Hello! I’m new to the Framework Community and would like to ask a few questions about the Framework Laptop 16 Expansion Bay Shell.

In the electrical documentation for the Expansion Bay Shell on GitHub, there’s a reference to the VADP_GPU pins. It’s described as follows:
“This allows power to be fed from the Expansion Bay back into the laptop in an Extended Battery scenario or another type of card that has a power supply attached.”
(Link to the text: click)

This repository is a bit confusing because it still contains TODOs and mentions that the information isn’t final since the Laptop 16 wasn’t in production at the time. However, the laptop is definitely available now.

So, how exactly does VADP_GPU work? Is it a power input for a battery charging converter that accepts 5–48V? Or is it connected in parallel with the main battery? Is it possible to build an external, swappable battery using this connection? Also, what happens if a USB-C charger and such a battery are connected at the same time — could it damage the battery or circuitry?

Additionally, the documentation mentions that there’s a USB 2.0 interface available through the data pins. Can I break that out to the rear panel of the laptop to connect a mouse?

2

Hi. I think you are correct. I don’t think there is enough public information to answer your questions.
If you have a 20V usb-c charger, and then battery2 outputting 15V, what does happen. It looks like both those are connected to the same wire feeding into the charger chip.

3

so VADP_GPU is basically receiving 5-48V at any moment? How to setup current limit if there’s no PD in this? is there some diode circuit which picks higher voltage among this input or any of USB-C’s?
Is there a better and more detail documentation on expansion bay shell and how it works with Laptop 16?

4

Hi @Sergey_Lunov

This community forum is just for other users. We don’t know any more than you.

I would recommend raising a support request from the Framework web site as that will get a response from FW themselves.

They are quite supportive of people making things that attach to the FW laptops.

5

I thought I could get some help from Framework here

Thank you, my bad :upside_down_face: