If you have a hostile charger all bets are off the table, but the cheap USB-C chargers just do 5v/3A (or less current) and the USB-PD chargers all use one of a

If you have a hostile charger all bets are off the table, but the cheap USB-C chargers just do 5v/3A (or less current) and the USB-PD chargers all use one of a few controller chips.