Why does fast charging only works until about 50%-60% of battery capacity and charge rate slows down after that?

Question

Why does fast charging only works until about 50%-60% of battery capacity and charge rate slows down after that?

In: Engineering

Answer 1

The charging circuitry requires power to be limited when the battery is nearing full, there’s less space for energy to get in and forcing it in could be dangerous. This mostly applies to phone batteries (Li-Ion), car batteries can take much more abuse.

On modern phones they found different ways to produce the same type of battery so they can force more power by increasing the voltage (and therefore the amperage). But this is dependent on the fast charging standard or the device’s manufacturer. Probably yours has an older or simpler system.