this post was submitted on 24 Jun 2024
29 points (91.4% liked)
Linux
46794 readers
970 users here now
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Rules
- Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
- No misinformation
- No NSFW content
- No hate speech, bigotry, etc
Related Communities
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
The charge controller's idea of what's going on is totally independent of what's going on in the CPU. It doesn't know and doesn't care about your OS.
Multiple calibration cycles are pointless. Doing it once (every few months) should be enough. Or doing it never is fine too. I had one laptop (thinkpad l480) that would get out of calibration, such that the charge controller would go straight from 45% charge to 1%.
What's happening is that lithium batteries have a very steady voltage for most of their usage. The voltage mostly changes at the top and bottom ~%10 of charge. Everything else in the middle is guesswork - the charge controller has to measure and count every drop of current going in and out of the battery. Measuring consists of a current meter - you put a very low value resistor in line and measure microvolts of drop across it. You can have a high precision current meter, or you can have one that "doesn't burn a lot of power in the dropper resistor", not both. Some systems have too inaccurate a meter. Some have phantom draws that aren't well accounted for (like the battery's own internal resistance and drain). If the battery spends all of its time in the "voltage never changes" region, the current counter's guess will diverge from reality.
When you discharge/recharge the battery, you are forcing its current counter to realign itself with reality. Whatever it thinks is left in the battery, nope that's really zero when we drop to ~3.2 volts.
Thanks! Very useful info.