iphone 13 battery

Hello, I have had an iPhone 13 brand new for 2 weeks now and I have the following problem. Battery drains from 100 to 20 in about 5 hours of total display time.

This is my second iPhone 13 that behaves like this, I returned the first one because I thought it was defective.

And all my friends who bought an iPhone 13 in 2021/2022 enjoy 2 days of battery life.

I don't know if this batch of production is of low quality batteries or if I got 2 defective units.

And this is not about excessive usage as they are not playing games on the phone background app refresh is stopped, location services are stopped, brightness is reduced and low power mode is ON,

And 26 GB of memory is full, so there is nothing to load it.
My question is what could be the cause of this, because I am convinced that the battery does not drop normally, because a friend who has an iPhone 13 for a year has a battery at 88% battery health and it drops more slowly than mine, and his phone is more loaded than anything on top.

Expect an answer.