It'll hurt the battery.
iphone12 can use 20 or 30w wireless fast charge, will not damage the battery, but the highest power supported by Apple xr is 18w, but now the brand of 20w fast charge is compatible with 18w, it is best to charge more than 20% of the remaining power. During the rapid charging process, the battery temperature will rise, and the battery life will be shortened in a high temperature environment for a long time. However, it is best to charge at more than 20% of the remaining power.