Why is it that mobile phones these days promises to charge your phone up to 80 % in like half and hour.. but it takes another 20 minutes to charge to 100%? Why can’t it just go all the way?

Question

Same with electric cars… I always see “fast charge you car up to 80 percent or so in X amount of time but the rest is not fast?

In: Engineering

Answer 1

It’s like packing a room full of people, when the room is empty it’s easy for people to walk in. After a certain point people keep bumping into each other and it’s harder to squeeze more in.