iPhone 14 Battery health and backup reduced

Hi Community,

My iPhone is 5 months old

Battery health was at 100% when I checked it 2-3 days ago

I checked yesterday that it dropped directly to 96% from 100%.

iPhone’s battery backup is also less after the recent update

I want to know how it got reduced directly by 4% and not percent by percent

I try to charge my iPhone within 20-80% but I use it on low battery percent.

I switched on 5G mode and charged it 100% then I noticed a decrease in battery health

Secondly, does Apple swap iPhones for this as it’s a new iPhone?

Thanks!

[Edited by Moderator]