My powerbank's input supports 5V-3A, 14.5V-2A and 20V-1.5A (30W) and I was wondering if recharging this powerbank with a 5V-2A wall charger would ruin the powerbank if plugged into its USB-C input. That supports up to 20V-1.5A (30W)
It is my understanding that in order to enable fast-charging on my new powerbank, I would need at least a 30W USB-C PD wall charger and a USB-C to USB-C cable attached between my powerbank and the 30W PD wall charger. Replace USB-C to USB-C cable with lightning to USB-C if charging an Apple iPhone.
Added (1). I'm probably as confused as you are, and I'm sorry if it is really confusing.
Added (2). I also intend to charge my iPhone X/XS Max with this powerbank, but not sure if the chip inside these phones will allow fast charging from this 20V-1.5A (30W) powerbank.
Read more: Will a charging wall block of 5V 2A ruin a powerbank if the powerbank supports up to 20V-1.5A (30W) from its USB-C input?