How does this fast charging technology work?

01 Tem 14:59

Fast charging technologies are right up my alley because I recently had to deal with one of those "aggressive" chargers that came with a gaming laptop, and honestly, I was surprised that in 40 minutes it was at 80% without the battery heating up at all. The key is that these systems don’t suddenly "force" more amperage like they used to; instead, they negotiate with the battery in different stages. For example, Qualcomm’s Quick Charge standard detects the battery’s state and starts by delivering a lot of current (5V/3A), but as soon as the battery reaches a certain voltage, it automatically drops to 9V/2A or 12V/1.5A to avoid overloading the cells. I’ve tried a Xiaomi with fast charging, and in cold conditions, it lasts the same as a normal charger, but after 30 minutes, you already have 60%. As for it being new—it’s not. These tricks have been used for years in electric cars and power banks, but they became mainstream in phones with the first Snapdragon 800/810 chips. Right now, even my 5-year-old tablet with a MediaTek Helio P22 chip handles 15W without issues, though the battery doesn’t notice the difference because the software regulates it. That said, be careful with unofficial chargers: my cousin had a cheap "5V/3A" one that fried his laptop by trying to push 2A in reality.