Safely draining the battery

I just installed new battery to an old laptop running pretty bare-bones endeavourOS and herbstluftwm (+ lxsession to cover the need for a polkit agent). The battery manufacturer recommends fully charging and discharging the battery a few times after installing it. The question is how do I get the system to shut down safely when the battery’s about to die?

I’m guessing this will involve a systemd hook or something, but I haven’t been able to find anything that’s not DE-specific. Please feel free to just point me to a wiki page or whatever.

Leave it running in the BIOS/UEFI or GRUB boot loader screen. Nothing to break at that point, and it ensures the battery is fully drained.

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@drhoopoe
What type of battery is it?
NiMH, Lithium, or something else?

Even when using a Li-Ion battery, the manufacturer recommends that you sometimes discharge the battery to reset the controller.
I do this about once a year, leaving the laptop running on battery power on the BIOS screen.

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Li-Ion. It’s a 10-yo Acer laptop that I’ve recently dropped an SSD in, maxed out the RAM (8GB!), etc.

I haven’t fully discharged (i.e. on purpose! :wink: ) a Li-Ion battery ever, and they all have been working well. Instructions that I’ve heard (I’m no battery expert myself) are to keep a Li-Ion battery mostly between 50%-80% of charge. Also they’ve said that do not discharge fully.

NiMH batteries have been a different story.

Also I’ve kept the Li-Ion batteries fully disconnected from the laptops always when possible.

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Thanks, that works great as a solution to the immediate problem, but is there a way to tell the system to shut down when the battery hits a certain point?

Normally something like:

image

If you’re after something like a specific value (e.g. “power off at 25%”) then it should be possible, but I don’t know without looking… :thinking:

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Thanks. My issue was finding a DE-less solution, but the archwiki pointed me to powerkit, which seems to be exactly what I needed. It’s DE-independent and, among other things, it lets you specify a percentage at which to shut down (or hibernate or whatever).

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Woah! That’s pretty cool! :+1: