Welcome to the Dell Community  @laptoptitan 

It could be that the power from your AC is reducing???

It sounds like during heavy use the AC cannot provide sufficient power.

That's when the battery kicks in to make up the lack of power from the AC.

Do you know if you can borrow a 240W AC for testing purposes???

Best regards,

U2

I think the problem is the power supply. I used a different power supply and everything seems to be working smoothly.

But I still do not understand why the old power adapter for other laptops is no problem even when playing heavy games for a long time.