What is the best way to keep laptop's battery healthy and follow 80/40 rule

[blackernel]

I just bought my new laptop (Huawei D15) and thought about keeping the battery healthy for longer period. Almost everywhere it is adviced to follow The 80/40 rule where you plug in when it's 40% and unplug when 80%.
My question is, how can I maintain that other than looking at the battery indicator all the time? Is there a way to automate that? Moreover, when the laptop is powered off but charging, we can't see the battery percentage thus we can't maintain the 80/40 rule.

 

[MJS WARLORD]

I have never heard of the 40/80 rule before but i used to fly radio controlled planes and was told it was a bad idea to keep "topping up " a partially used battery because they will eventually suffer from something called cell blindness , example .... you have a battery with say 4 cells and if you keep topping them up some of the cells will become invisible so you think you have 4 fully charged cells but in actual fact you may only have 2.

I never charge my phone , tablet or laptop until the device tells me to.

 

[blackernel]

I have never heard of the 40/80 rule before but i used to fly radio controlled planes and was told it was a bad idea to keep "topping up " a partially used battery because they will eventually suffer from something called cell blindness , example .... you have a battery with say 4 cells and if you keep topping them up some of the cells will become invisible so you think you have 4 fully charged cells but in actual fact you may only have 2.

I never charge my phone , tablet or laptop until the device tells me to.

I got your point about cell blindness. But, battery technology is changing rapidly and I am not sure whether the 80/40 rule is more relevant for newer batteries or not. That rule helps saving the limited number of Lithium battery charging cycles.

 

[hotaru.hino]

Battery "Cell blindness" is known as the memory effect. It's only a problem with nickel based batteries.

Ultimately the best way to keep a lithium ion battery lasting the longest is simply keeping its temperature in a range that's reasonably comfortable for humans. I'm not being cheeky about this. If the battery is constantly over 40C or under 0C, then its performance and lifespan will suffer more than keeping it in some state of charge all the time.

Now some laptops do have some software that prevents the state of charge from going past a certain point (I know ASUS laptops can do this), but there's nothing in Windows natively as far as I know. But honestly, I wouldn't really worry about trying to maintain the battery. I've had laptops that I've kept plugged in more times than not and they've been able to maintain an excellent capacity over time. And while I haven't (or really can't) confirm it, it's also possible that laptop manufacturers may over-report the state of charge to account for wear. I know EV companies do this, where they claim 100% charged but the battery is really more like 80% charged. Although you could also confirm this anyway by checking the voltage reading using HWiNFO (a "fully charged" lithium battery usually sits around 4.2V * the number of cells it has). Laptop manufacturers also expect people to leave their laptops plugged in all the time anyway, so they've likely designed the charging circuitry to account for this.

In any case, I like Apple's explanation of battery capacity life span: your battery has an overall amount of charge like a savings account. Charging the battery is taking away from this overall amount, like putting money from savings into checkings.