I just basically ran through most of my collection of pd chargers and powerbanks to se what works and what doesn’t. Only tested with the laptop on and around 20% charge (and stress --cpu 16 to simulate max power draw).
It does indeed look like something may be a bit bugged with the pd controller (or the ec or something in between), all the 20V capable ones worked (well except that one sketch powerbank board but that one barely works at all, which sucks cause on paper it is exactly what I want). The 12v capable ones tend to need a kickstart (connecting and removing a directly working power source) but work fine after that.
Appart from one of the 12v powerbank bugging into 5v charging (it actually stayed charging untill I removed it doing about 2.2A into the direction of the laptop) more once 5v charging from non pd sources doesn’t seem to work at all which is kinda sad. Sure it’s mostly a gimmick but I like that gimmick and the laptop seems perfectly capable of charging off 5v once it decides to do so.
Here a list of the chargers tested with negotiated voltage and max observed current
- No name 45W powerbank → 20V 2A
- Baseus 65W powerbank → 20V 3A
- Baseus 100W multiport charger → 20V 4.5A
- Baseus 30W wallwart → 20V 1.4A
- Baseus 20W wallwart → 12V 1.5A (needed kickstart)
- No name 65W charger → 20V 3A
- Wotobeus 100W power brick → 20V 4.5A
- Wekome 40W wallwart → 20V 1.8A
- Random 100W powerbank board → fail (but that board is scuffed anyway)
- IP2368 powerbank board → 20V 4.5A
- Random 22W powerbank board type 1 → 12V 1.4A
- Random 22W powerbank board type 2 → 12V 1.5A (needed kickstart)
- Random 22W powerbank board type 3 → 12V 1.4A (needed kickstart, probably ocp looped otherwise)
- random qc3 powerbank → briefly powers after kickstart, does not stay on
- 5v only powerbank c to c → 5V 1.1A (needed kickstart)
- 5v only powerbank a to c → 5V 0.8A (needed kickstart)
- 5v phone power supply → 5V 0.8A (needed kickstart)
Edit: added retests of the 5v ones