I understand the design concept for to save a battery life but the issue is that the battery is dropable to 0% and so my laptop can turn off because of no power.
As an example, I can attach a printscreen (https://ibb.co/7pBzvQn) from today´s playing of World of Warcraft where after my ~3 hours of gaming, battery dropped on 43%, so it won´t stop on its 90-95% as it´s mentioned in the previous exist posts..
Is it a problem with laptop´s battery OR with a charger OR with a laptop itself?
I´d be grateful for any advices Thanks.
Sound like your charger may well be the issue. If you can get your hands on another charger (with the same specs only) to test on the laptop, or test yours on another laptop that uses the same kind of charger, you will be able to see if it is in deed the charger.
If you can't try another one, then I would consider taking it to a local tech who will be able to test the charger (just make sure they aren't going to charge a fortune to test it).
Should it in deed need replacing, just be sure you get an OEM charger and not an aftermarket one. Aftermarket batteries and chargers for laptops are not wise or safe choices.