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

Charging times of lithium based batteries are not linear. Up to about 80% are faster than from there on.