In 2013, the wire reported that you should plug in when the laptop battery gets to 40%, and unplug when it gets to 80%. Quoting from the article:
For example, Battery University states that a battery charged to 100 percent will have only 300-500 discharge cycles, while a battery charged to 70 percent will get 1,200-2,000 discharge cycles.
There was also a question posted on superuser in 2012 about the same thing with regard to Mac notebooks.
Question is: it's 2019. Should I still do this or have things changed? If it's still relevant, what's the best way to do this. It's tiring to constantly keep checking your battery percentage, although I've sorted the lower end out by making windows go into power saving mode once it reaches 40% (=I'll be notified).
Best Answer
According to Digital trends letting a laptop deplete to 20% and recharge full is fine.
A year ago I got a new laptop. During installation, Windows recommended a a constant 60% charge if possible. This would be the optimal battery life span setting. It had three options: 80% constant charge or 100%. The higher charge the lower expected life span would be. Since the laptop is only used in an office environment, I took that option. Don't know how much it's degraded since.
Using it plugged in does seem best to me. So far as I know it's due to the cells getting dirty over time as charge moves in/out. Certainly with a modern laptop that stops charging at that point it will mean your battery is untouched. And no dirt is build up. In which case your battery is just a backup. But if you're not plugged in all the time, I don't know what's best.