How is battery health measured?

I’m only about a month into using Manjaro (specifically, KDE Plasma) on an ASUS X556 laptop / Intel Core i7. As I was adjusting some power management settings, I noticed the battery and brightness menu also provides a battery health measurement.

Not having seen this measurement before, I’m curious how this measurement is calculated. Additionally, is it a component of KDE Plasma? Manjaro itself?

Thank you!

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This is done at a lower level, and the battery itself forwards the information to the kernel/desktop/widget.

Some BIOSes (UEFI) also have additional battery health checks and optimizations that are OS-independent.

For reference, some manufacturer’s :green_apple: batteries are considered to meet the requirements as refurbished if it still retains 80% or more of its original rated capacity.

Keeping an Li-ion battery “healthy” is an unfair catch-22:

  • The more discharge-recharge cycles it goes through, the more it wears out the cells. (The deeper the discharge-recharge, the worse!)
  • However if you leave it indefinitely plugged in at 100%, it essentially keeps the battery at a high “stress” level (think “high pressure” in a water tank.)
  • Of course, if you never use the battery, well, then you’re not getting you money’s worth out of it. :wink:

I’ve found the best results with: never charge an Li-ion battery beyond (self-reported) 80%, and to not let it drop below 40%. This works splendidly for phones, but it’s not as feasible with a laptop for obvious reasons. (“Never” is a strong word. Perhaps “only when really necessary”.)

Using a cheap USB fan to keep the battery cool during recharge also helps. (Doesn’t hurt to have one placed on your night-stand or desk, and turn it on to blow air over the phone as it’s charging.)

:ice_cube: :battery:

Further reading on a more nuanced understanding, if interested: BU-808: How to Prolong Lithium-based Batteries - Battery University


I’ve marked this answer as the solution to your question as it is by far the best answer you’ll get.

However, if you disagree with my choice, please feel free to take any other answer as the solution to your question or even remove the solution altogether: You are in control! (If you disagree with my choice, just send me a personal message and explain why I shouldn’t have done this or :heart: or :+1: if you agree)

P.S. In the future, please don’t forget to come back to your question after your issue has been solved and click the 3 dots below the answer to mark a solution like this below the answer that helped you most:
so that the next person that has the exact same problem you just had will benefit from your post as well as your question will now be in the “solved” status.

I completely agree and will be sure to keep an eye on posts - thanks!

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