We all know that devices can have their batteries weaken over time if you leave them charging for too long. Why does that happen and why can’t our devices just stop taking in power / cut off right when it’s full?

Question

On my own phone there’s a function where it can stop charging at 95% to protect the battery health. Why can’t it do this at 99.99% and present it as 100%? It would be unnoticeable to users and would prevent the overcharge issue, right?

In: Technology

Answer 1

The issue doesn’t just happen at 100%, it just gets worse as it gets closer to 100%. So keeping something charged at a high percentage for a long time is harmful, not just 100%. So obviously 99% wouldn’t make too much of a difference.