So I have an L390 Yoga with USB-C charging. Original adapter works at full speed. I got a 45W power bank, works at full speed.
But that was just a coincidence.
I already tried 5 other adapters and all can only charge it at 10W with 5V. 3 were 22.5W, so maybe, but now I got a 45W GaN adapter, with the same 20V 2.25A as the power bank, yet again just 10W. It even has PPS.
I also tried a 66W adapter I have, with 20V 3.25A mode, 10W again.
The only 3rd party thing that works is Choetech B653 power bank.
I have also tried 2 different cables, one of which is rated at 120W, but both only work with the power bank.
So what am I missing? Or is it just some Lenovo BS to make you use official adapter?
Like this it’s faster to charge the power bank, and then the laptop from it.
Edit: Switches to 20V when I connect something to USB-A on the adapter, but keeps turning off and on repeatedly (the adapter).
Maybe just that model? I’ve got an X1 carbon. It expects 45W and will run from anything that spits out 20V. Even hooked it into a 20W power bank. It complained that the supply was below expectations and that the battery might not charge but it worked.
Hmmm, it does switch to 20V when something is connected to the adapters USB-A, but will keep restarting (the adapter).