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

It’s not over-charging that causes batteries to degrade, it’s just *being charged* that does it with the degradation being relative to how charged the battery is.

So 99% charged won’t really be any better, but say 90% will be that bit better for it.

Because of this the newer Android OS lets you set a max charge between 70-100%, I have my phone set to 90% so once it hits that it stops charging.

I’m using my old phone as a remote camera so because it’s always plugged in I have it limited to 70% to make becoming a spicy pillow less likely (I hope)