Got a knock-off 85w MagSafe charger recently, but it didn't work.

After a bit of research, it turns out you can use the MagSafe end on any DC output seemingly up to or around 20V. I found an old Acer gaming laptop charger I had (19V), chopped its barrel connector of, put the MagSafe wire on it, and it works nicely! Registers 85w under macOS, and seemingly handles ok under load.