I know common VOOC charger have fast charging rate of 18W(9V/2A). But how it possible even current is only 2A. I mean 2A current have only stored charge 2000mAh(2A*1h). How changing voltage can charge battery faster? On other side Oneplus Dash charger supports upto 20W(5V/4A). This makes sense that higher current can charge battery faster. But again how can just 5V can charge battery to 4A rating?
Thnaks for answer/comment. Corrections and suggestions are welcome.