diff --git a/monitor/batteryIcon.desktop b/monitor/batteryIcon.desktop
new file mode 100644
index 0000000..ae2c34d
--- /dev/null
+++ b/monitor/batteryIcon.desktop
@@ -0,0 +1,9 @@
+[Desktop Entry]
+Type=Application
+Name=Battery Icon
+Comment=Battery tray icon for Argon ONE UP
+Exec=/usr/bin/python3 /home/joachim/git/battery-argon40/monitor/batteryIcon.py
+Icon=battery
+Terminal=false
+Categories=System;Monitor;
+X-GNOME-Autostart-enabled=true
diff --git a/monitor/batteryIcon.py b/monitor/batteryIcon.py
new file mode 100755
index 0000000..7ee7345
--- /dev/null
+++ b/monitor/batteryIcon.py
@@ -0,0 +1,163 @@
+#!/usr/bin/env python3
+"""
+Battery tray icon for Argon ONE UP on Wayland (labwc).
+Reads SOC from /sys/class/power_supply/BAT0/capacity and charging
+status from AC0/online. Updates icon every 5 seconds.
+"""
+
+import sys
+import os
+import time
+from PyQt5.QtWidgets import QApplication, QSystemTrayIcon, QMenu, QAction
+from PyQt5.QtGui import QIcon, QPainter, QColor, QFont, QPixmap
+from PyQt5.QtCore import QTimer, Qt
+
+SYSFS_BAT_CAPACITY = "/sys/class/power_supply/BAT0/capacity"
+SYSFS_BAT_STATUS = "/sys/class/power_supply/BAT0/status"
+SYSFS_AC_ONLINE = "/sys/class/power_supply/AC0/online"
+UPDATE_INTERVAL_MS = 5000
+
+
+def read_sysfs(path, default=None):
+    try:
+        with open(path) as f:
+            return f.read().strip()
+    except (FileNotFoundError, PermissionError, OSError):
+        return default
+
+
+def make_battery_icon(percent, charging):
+    """Draw a battery icon with percentage text."""
+    size = 64
+    pix = QPixmap(size, size)
+    pix.fill(Qt.transparent)
+    p = QPainter(pix)
+    p.setRenderHint(QPainter.Antialiasing)
+
+    # Battery outline
+    bx, by, bw, bh = 8, 14, 48, 36
+    # Terminal nub
+    nx, ny, nw, nh = bx + bw, 24, 6, 16
+
+    p.setPen(QColor(200, 200, 200))
+    p.setBrush(Qt.NoBrush)
+    p.drawRoundedRect(bx, by, bw, bh, 4, 4)
+    p.drawRoundedRect(nx, ny, nw, nh, 2, 2)
+
+    # Fill level
+    margin = 3
+    fill_max_w = bw - 2 * margin
+    fill_w = max(1, int(fill_max_w * percent / 100))
+    fill_x = bx + margin
+    fill_y = by + margin
+    fill_h = bh - 2 * margin
+
+    if charging:
+        fill_color = QColor(100, 200, 255)  # blue when charging
+    elif percent <= 10:
+        fill_color = QColor(255, 60, 60)    # red when critical
+    elif percent <= 25:
+        fill_color = QColor(255, 180, 0)    # orange when low
+    else:
+        fill_color = QColor(80, 220, 80)    # green normal
+
+    p.setPen(Qt.NoPen)
+    p.setBrush(fill_color)
+    p.drawRoundedRect(fill_x, fill_y, fill_w, fill_h, 2, 2)
+
+    # Percentage text
+    font = QFont("Sans", 11, QFont.Bold)
+    p.setFont(font)
+    p.setPen(QColor(255, 255, 255))
+    text = f"{percent}%"
+    p.drawText(bx, by, bw, bh, Qt.AlignCenter, text)
+
+    # Charging indicator (lightning bolt)
+    if charging:
+        font2 = QFont("Sans", 9)
+        p.setFont(font2)
+        p.setPen(QColor(255, 255, 100))
+        p.drawText(0, 0, size, 16, Qt.AlignCenter, "⚡")
+
+    p.end()
+    return QIcon(pix)
+
+
+class BatteryTray:
+    def __init__(self):
+        self.app = QApplication(sys.argv)
+        self.app.setQuitOnLastWindowClosed(False)
+
+        # At login the panel may not have started its system tray yet.
+        # Wait for it instead of giving up, so autostart works after a reboot.
+        deadline = time.monotonic() + 120
+        while not QSystemTrayIcon.isSystemTrayAvailable():
+            if time.monotonic() > deadline:
+                print("System tray not available after 120s", file=sys.stderr)
+                sys.exit(1)
+            time.sleep(2)
+
+        self.tray = QSystemTrayIcon()
+
+        # Context menu
+        menu = QMenu()
+        self.status_action = QAction("Battery: --")
+        self.status_action.setEnabled(False)
+        menu.addAction(self.status_action)
+        menu.addSeparator()
+        quit_action = QAction("Quit")
+        quit_action.triggered.connect(self.app.quit)
+        menu.addAction(quit_action)
+        self.tray.setContextMenu(menu)
+
+        # Initial update
+        self.update()
+
+        # Timer for periodic updates
+        self.timer = QTimer()
+        self.timer.timeout.connect(self.update)
+        self.timer.start(UPDATE_INTERVAL_MS)
+
+        self.tray.show()
+
+    def update(self):
+        cap_str = read_sysfs(SYSFS_BAT_CAPACITY)
+        status = read_sysfs(SYSFS_BAT_STATUS, "Unknown")
+        ac_str = read_sysfs(SYSFS_AC_ONLINE, "0")
+
+        if cap_str is not None:
+            try:
+                percent = int(cap_str)
+            except ValueError:
+                percent = 0
+            charging = (ac_str == "1" or status == "Charging")
+            icon = make_battery_icon(percent, charging)
+            self.tray.setIcon(icon)
+
+            if charging:
+                state = "Charging"
+            elif ac_str == "1":
+                state = "On AC"
+            else:
+                state = "Discharging"
+            tooltip = f"Battery: {percent}% ({state})"
+            self.tray.setToolTip(tooltip)
+            self.status_action.setText(tooltip)
+        else:
+            # No battery sysfs - module not loaded
+            icon = make_battery_icon(0, False)
+            self.tray.setIcon(icon)
+            self.tray.setToolTip("Battery: N/A (module not loaded?)")
+            self.status_action.setText("Battery: N/A (module not loaded?)")
+
+    def run(self):
+        return self.app.exec()
+
+
+def main():
+    bt = BatteryTray()
+    sys.exit(bt.run())
+
+
+if __name__ == "__main__":
+    main()