Gleipnir

A Decky Loader plugin for the AYN Thor on Armada OS that holds the battery at 80 % while plugged in, to slow battery wear. Named for the thin ribbon that bound Fenrir: a small thing that restrains a large force.

Status: verified on one Thor (2026-10-08, Armada 20261006.9c7dd3e, kernel 7.2.6). Writing 0 to constant_charge_current stopped charging, the 80 % clamp held through 18 minutes of a game, it released at 77 % and charging resumed. Other builds are untested. Gleipnir still installs in watch-only mode and does nothing to charging until its built-in measured test passes on your kernel. Read docs/evidence.md for what is and is not known. Not affiliated with AYN or Armada.

What it does

• Watches the battery. When the Thor is plugged in at 80 % or more it sets the battery manager's charge current limit to the "stop charging" value; when you unplug it, or the level falls to 77 %, it puts back the value it found.
• Ships a safety test (usually two to four minutes: the limit takes about a minute to act) that proves, on your Thor, that the limit stops charging and that charging resumes after release. Only a pass arms the daemon, and the pass is tied to your kernel version.
• Logs every decision to the journal with a battery snapshot, runs a watchdog for a limit that does nothing, and restores the limit on every exit path.

Requirements

An AYN Thor on Armada OS with Decky Loader, a kernel that exposes constant_charge_current (Armada's does; the surveyed build 20261006.9c7dd3e has it), SSH key access to the Thor and sudo there for the one-time install. Python 3 and bash are already on the Thor.

Install

git clone https://github.com/venatrix-ritz/Gleipnir && cd Gleipnir
./scripts/deploy.sh armada@<thor-ip>      # or set THOR_HOST / local/thor.env; needs SSH keys and sudo on the Thor

Then in Game Mode: Steam menu, Decky, Gleipnir, Install daemon; plug in the charger (battery between 10 and 90 %), Run test. After a PASS the daemon arms itself within 30 seconds. What each message means, and how to uninstall: docs/troubleshooting.md.

If anything ever looks wrong, restore normal charging with:

sudo systemctl stop gleipnir && echo 9000000 | sudo tee /sys/class/power_supply/battery/constant_charge_current

Documentation

Page	What is in it
How it works	the control it uses, the daemon loop and thresholds, the verification marker
Safety	the rules it follows, failure modes, recovery, what is not guaranteed, security notes
Testing	the on-device test step by step, the simulated suites, recorded results
Command-line reference	every mode, exit codes, JSON status, files
Evidence	observed values and sources, with the open questions
Troubleshooting	what each message means and what to do
Changelog · Credits	history; who this builds on

Files

Path	What
main.py, plugin.json (flags: ["root"]), dist/index.js	the Decky plugin: installs, starts, stops and tests the daemon; shows status and log. Root, like Armada's own privileged plugins
bin/gleipnir	the daemon, status report, safety test and restore command in one script
systemd/gleipnir.service	the unit
tests/	run-tests.sh (daemon against a simulated battery) and test_backend.py (plugin backend)

Credits and licence

Adapted from MgeeeeK's thor-charge-limit; see CREDITS.md. MIT for the plugin (LICENSE); bin/gleipnir is GPL-2.0-or-later (SPDX header in the file, terms in LICENSES/GPL-2.0.txt).