Battery rather weak

I have the xiami lite 10.
Even if it has a big battery the battery drains even in battery safer mode quite fast. I have a Samsung A8 from 2 years ago and the battery is quite similar.
What can i do about it?

Have you bought your Xiaomi from iodé? If so, can you email iodé with you order number?
Otherwise, an app could drain your battery, if the battery is not defective already. You can check if your battery manager doesn’t report anything abnormal (settings → battery)

Yes i ordered it from iodé themself.
There is no battery that drains it. Its just a weak battery.
I decided against the samsung s9 due to its weak/small battery even though i would have preferred having a ip protection.