Adventures in USB-C charging :) Any ideas welcome

Thread Starter


Joined Apr 5, 2019
I had this dream for a "system" of one charger type, one cable type and one power-bank type for all my devices...

- Got a laptop that "can be charged over USB-C", rated 65w
- Got a charger that offers USB-C-PD-3.0, rated 65w
- Got a power-bank that offers USB-C-PD-3.0, rated 65w
- Got USB-C cables rated for 65w

All devices, power sources and cables work well with each other, except the battery and the laptop!
On some investigation, I learned that USB-C isn't just USB-C. It could be a USB-C-PD (1/2/3) or something else. My laptop is actually a Thunderbolt-4...
Again, the charger works fine, on the laptop and any other device.
I got all sorts of good,+65w cables I tried. I don't think it's a "bad cable" or "not enough watts" problem.

I now want to investigate. My main lines are:
A) If I can splice one of my cables on a perfboard and poke around with a meter, maybe even a scope/logic analyzer is called for? The idea is, if I can see what the charger is doing that the battery is not doing and try to hack an adapter or something...
- The problem with this approach is that I feel those USB protocols are anything but straight-forward. I don't think I'll go as far as programming an MCU and all sorts of logic like that, to reconcile both gadgets.
B) Assuming the regular laptop charging port (a barrel connector) is more simple (?), perhaps I am better off just trying to get the juice out of the battery, using the most simple USB-PD protocol that it supports and then a simple adapter should be able to feed the regular laptop charging port - I'll stick the adapter on the laptop. So, that my system is always ready :)

Any thoughts, ideas, directions, product suggestions welcome.


Joined Jul 10, 2017
Can I assume that the power bank and battery that you mention are the same device?
Some newer laptops can be charged by the USB-C port like yours, but not all of them.
Power banks usually have different charging and output ports. If you have one with a USB-C connector, that will probably be the output.
Here is a bit of information to get you up to date: