Battery Draining too quickly

i have a new iphone 13 pro, it’s battery health is 100% as of now. the problem is it’s screen time, usually it’s about 4-6 hours but sometimes it would start draining for no apparent reason

i was at 60% 12 hours later it dropped to 31% even through i used it for maximum 15 minutes that too to check maps and attend a few calls. I wasn’t connected to wifi and i have also disabled background app refresh.

is this normal or is there something wrong with my model in particular?