I often wonder, how does my laptop’s charger and battery control work? Because I’ve been in situations where I’m charging my laptop from a weak charger that’s under-rated for the laptop’s draw. For example, I have a 20W PD charger, and my laptop draws between 15-45W depending on what I’m doing. If I’m just doing some simple word processing work, my battery can even get a little charge while plugged into my charger. But if I play a 3D game, then my laptop maxes out the 20W PD charger, then supplements from the battery.
How does my laptop know how to split the power demand, and how does it draw exactly the right amount of power from the battery?