diff --git a/CLAUDE.md b/CLAUDE.md
index d1dac06..621f972 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -7,7 +7,16 @@ Reproduzierbares Arch-Linux-Setup basierend auf archinstall + Post-Install-Autom
 - `config/` — archinstall-Konfiguration (inkl. custom-commands die das Repo nach /opt/moonarch klonen, root-owned)
 - `scripts/` — Post-Install- und Helper-Scripts
 - `packages/` — Paketlisten (offiziell + AUR), getrennt gepflegt
-- `defaults/` — XDG-Configs, Shell-Config, Helper-Binaries, systemd User-Services, greetd/moongreet-Config, Wallpaper
+- `defaults/` — XDG-Configs, Shell-Config, Helper-Binaries, systemd Services, udev-Regeln, greetd/moongreet-Config, Wallpaper
+
+## Battery Conservation Mode
+
+Laptops mit `charge_control_end_threshold`-Support (ThinkPad, Framework, etc.) erhalten einen Waybar-Toggle:
+- Klick auf das Battery-Modul schaltet zwischen 80% und 100% Ladegrenze um
+- Bei aktiver Conservation erscheint ein ♥-Icon neben der Battery-Anzeige
+- Zustand wird in `/var/lib/moonarch/batsaver-threshold` persistiert und beim Boot via systemd-Service wiederhergestellt
+- udev-Regel gibt Gruppe `wheel` Schreibzugriff auf den Threshold (kein sudo nötig)
+- Auf Desktops ohne Battery-Support versteckt sich das Feature komplett
 
 ## Konventionen
 
diff --git a/DECISIONS.md b/DECISIONS.md
index 79f1602..386b456 100644
--- a/DECISIONS.md
+++ b/DECISIONS.md
@@ -1,5 +1,11 @@
 # Decisions
 
+## 2026-04-08 – Battery conservation mode: udev + sysfs + Waybar toggle
+- **Who**: Dominik, ClaudeCode
+- **Why**: Laptops with `charge_control_end_threshold` support benefit from limiting charge to 80% to extend battery lifespan. Needed a user-friendly toggle without requiring sudo.
+- **Tradeoffs**: udev RUN approach for permissions (group wheel gets write access) vs polkit/pkexec (password prompt on every toggle). Chose udev for seamless UX. State persisted in `/var/lib/moonarch/` (system-wide, not per-user) — acceptable since charge threshold is a hardware setting, not a user preference. Fixed 80% threshold instead of configurable — KISS, matches industry standard.
+- **How**: udev rule grants wheel group write on `charge_control_end_threshold`. Toggle script writes sysfs + state file. systemd oneshot service restores on boot. Waybar shows ♥ icon when active, hidden when inactive. Click on battery module toggles.
+
 ## 2026-04-07 – Walker theme: gtk-inherit → moonarch with fixed colors
 - **Who**: Dominik, ClaudeCode
 - **Why**: gtk-inherit theme relied on GTK4 color inheritance which works but doesn't update live when switching GTK themes (Walker service needs restart). Explicit color definitions make the theme self-contained and predictable.
diff --git a/README.md b/README.md
index 54cf740..f1c7460 100644
--- a/README.md
+++ b/README.md
@@ -131,11 +131,15 @@ defaults/
     moonarch-waybar-cpugov        Waybar module: CPU governor status
     moonarch-waybar-gpustat       Waybar module: GPU utilization
     moonarch-waybar-hidpp         Waybar module: Logitech HID++ device battery
+    moonarch-waybar-batsaver      Waybar module: battery conservation mode indicator
+    moonarch-batsaver-toggle      Toggle battery charge limit (80% ↔ 100%)
 
   shell/zshrc                   Zsh config: prompt, aliases, FZF, completion
   etc/greetd/                   greetd daemon + greeter Niri config
   etc/moongreet/                moongreet configuration
   etc/systemd/user/             Systemd user services (cliphist, kanshi, walker, nautilus)
+  etc/systemd/system/           System service (battery conservation restore on boot)
+  etc/udev/rules.d/             udev rules (battery threshold permissions)
   backgrounds/wallpaper.jpg     Default wallpaper (shared by desktop, greeter, lock screen)
 ```
 
diff --git a/defaults/bin/moonarch-batsaver-toggle b/defaults/bin/moonarch-batsaver-toggle
new file mode 100755
index 0000000..beb483d
--- /dev/null
+++ b/defaults/bin/moonarch-batsaver-toggle
@@ -0,0 +1,28 @@
+#!/usr/bin/bash
+# ABOUTME: Toggles battery conservation mode between 80% and 100% charge limit.
+# ABOUTME: Writes to sysfs (immediate) and state file (persistence across reboots).
+
+THRESHOLD_FILE="/sys/class/power_supply/BAT0/charge_control_end_threshold"
+STATE_DIR="/var/lib/moonarch"
+STATE_FILE="${STATE_DIR}/batsaver-threshold"
+CONSERVATION_LIMIT=80
+
+[[ -f "$THRESHOLD_FILE" ]] || exit 1
+
+CURRENT=$(cat "$THRESHOLD_FILE")
+
+if [[ "$CURRENT" -le "$CONSERVATION_LIMIT" ]]; then
+    NEW=100
+else
+    NEW="$CONSERVATION_LIMIT"
+fi
+
+# Apply immediately
+echo "$NEW" > "$THRESHOLD_FILE" || exit 1
+
+# Persist for next boot
+mkdir -p "$STATE_DIR"
+echo "$NEW" > "$STATE_FILE"
+
+# Signal Waybar to refresh the batsaver module (SIGRTMIN+9)
+pkill -RTMIN+9 waybar
diff --git a/defaults/bin/moonarch-waybar-batsaver b/defaults/bin/moonarch-waybar-batsaver
new file mode 100755
index 0000000..6d50a26
--- /dev/null
+++ b/defaults/bin/moonarch-waybar-batsaver
@@ -0,0 +1,19 @@
+#!/usr/bin/bash
+# ABOUTME: Waybar module showing battery conservation mode status.
+# ABOUTME: Outputs heart icon when active (threshold ≤80), empty when inactive.
+
+THRESHOLD_FILE="/sys/class/power_supply/BAT0/charge_control_end_threshold"
+
+# No battery threshold support → no output → Waybar hides module
+[[ -f "$THRESHOLD_FILE" ]] || exit 0
+
+THRESHOLD=$(cat "$THRESHOLD_FILE")
+
+if [[ "$THRESHOLD" -le 80 ]]; then
+    jq --compact-output -n \
+        --arg text "♥" \
+        --arg tooltip "Battery Conservation: ON (limit ${THRESHOLD}%)" \
+        --arg class "on" \
+        '{text: $text, tooltip: $tooltip, class: $class}'
+fi
+# Threshold > 80 → no output → Waybar hides module
diff --git a/defaults/etc/systemd/system/moonarch-batsaver.service b/defaults/etc/systemd/system/moonarch-batsaver.service
new file mode 100644
index 0000000..8f1a2b7
--- /dev/null
+++ b/defaults/etc/systemd/system/moonarch-batsaver.service
@@ -0,0 +1,15 @@
+# ABOUTME: Restores battery charge threshold from saved state on boot.
+# ABOUTME: Only runs on laptops with threshold support and a saved state file.
+
+[Unit]
+Description=Restore battery conservation mode threshold
+After=sysinit.target
+ConditionPathExists=/sys/class/power_supply/BAT0/charge_control_end_threshold
+ConditionPathExists=/var/lib/moonarch/batsaver-threshold
+
+[Service]
+Type=oneshot
+ExecStart=/bin/sh -c 'cat /var/lib/moonarch/batsaver-threshold > /sys/class/power_supply/BAT0/charge_control_end_threshold'
+
+[Install]
+WantedBy=multi-user.target
diff --git a/defaults/etc/udev/rules.d/90-moonarch-battery.rules b/defaults/etc/udev/rules.d/90-moonarch-battery.rules
new file mode 100644
index 0000000..1baa703
--- /dev/null
+++ b/defaults/etc/udev/rules.d/90-moonarch-battery.rules
@@ -0,0 +1,4 @@
+# ABOUTME: udev rule granting wheel group write access to battery charge threshold.
+# ABOUTME: Enables unprivileged toggling of conservation mode via moonarch-batsaver-toggle.
+
+SUBSYSTEM=="power_supply", ATTR{type}=="Battery", RUN+="/bin/sh -c 'chgrp wheel /sys%p/charge_control_end_threshold 2>/dev/null; chmod g+w /sys%p/charge_control_end_threshold 2>/dev/null'"
diff --git a/defaults/xdg/waybar/config b/defaults/xdg/waybar/config
index e07475f..952ad75 100644
--- a/defaults/xdg/waybar/config
+++ b/defaults/xdg/waybar/config
@@ -21,7 +21,7 @@
         "bluetooth",
         "group/sound",
         "backlight",
-        "battery",
+        "group/battery",
         "group/indicators"
     ],
     "group/indicators": {
@@ -58,6 +58,13 @@
             "transition-left-to-right": true
         }
     },
+    "group/battery": {
+        "orientation": "inherit",
+        "modules": [
+            "battery",
+            "custom/batsaver"
+        ]
+    },
     "group/sys": {
         "orientation": "inherit",
         "modules": [
@@ -306,13 +313,26 @@
         },
         "format": "{capacity}% {icon}",
         "format-icons": [
-            "",
-            "",
-            "",
-            "",
-            ""
+            "󰂎",
+            "󰁺",
+            "󰁻",
+            "󰁼",
+            "󰁽",
+            "󰁾",
+            "󰁿",
+            "󰂀",
+            "󰂁",
+            "󰂂",
+            "󰁹"
         ],
-        "max-length": 25
+        "max-length": 25,
+        "on-click": "moonarch-batsaver-toggle"
+    },
+    "custom/batsaver": {
+        "exec": "moonarch-waybar-batsaver",
+        "return-type": "json",
+        "interval": 30,
+        "signal": 9
     },
     "bluetooth": {
         // "controller": "controller1", // specify the alias of the controller if there are more than 1 on the system