Show battery power draw from sensors in waybar

Replace the built-in battery module with a custom/battery script that
combines sysfs capacity/status with the power1 reading from `sensors`,
displaying it as "85% (5.4W)" next to the icon.

config/waybar/config.jsonc

@@ -5,7 +5,7 @@
   "spacing": 6,
   "modules-left": ["sway/workspaces", "sway/mode"],
   "modules-center": ["clock"],
-  "modules-right": ["cpu", "memory", "custom/network", "pulseaudio", "backlight", "battery", "tray", "custom/power"],
+  "modules-right": ["cpu", "memory", "custom/network", "pulseaudio", "backlight", "custom/battery", "tray", "custom/power"],
   "sway/workspaces": {
     "disable-scroll": false,
     "all-outputs": false,
@@ -17,7 +17,7 @@
   "custom/network": { "exec": "~/.config/waybar/scripts/network-cycle.sh", "return-type": "json", "interval": 300, "signal": 8, "on-click": "~/.config/waybar/scripts/network-cycle.sh next", "on-click-right": "~/.config/waybar/scripts/network-cycle.sh copy" },
   "pulseaudio": { "format": "{icon} {volume}%", "format-muted": "󰝟 muted", "format-icons": ["󰕿", "󰖀", "󰕾"], "tooltip-format": "{desc}", "on-click": "wpctl set-mute @DEFAULT_AUDIO_SINK@ toggle", "on-click-right": "~/.config/waybar/scripts/audio-output-cycle.sh" },
   "backlight": { "format": "󰃠 {percent}%" },
-  "battery": { "states": { "warning": 30, "critical": 15 }, "format": "{icon} {capacity}%", "format-charging": "󰂄 {capacity}%", "format-icons": ["󰁺", "󰁼", "󰁾", "󰂀", "󰁹"] },
+  "custom/battery": { "exec": "~/.config/waybar/scripts/battery-power.sh", "return-type": "json", "interval": 10, "tooltip": true },
   "tray": { "spacing": 8 },
   "custom/power": {
     "format": "󰐥",

config/waybar/scripts/battery-power.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+bat_dir="/sys/class/power_supply/BAT0"
+capacity=$(<"$bat_dir/capacity")
+status=$(<"$bat_dir/status")
+
+power=$(sensors -j 2>/dev/null | python3 -c '
+import json, sys
+data = json.load(sys.stdin)
+for chip, fields in data.items():
+    if not chip.startswith("BAT"):
+        continue
+    power1 = fields.get("power1")
+    if power1:
+        print(round(next(iter(power1.values())), 1))
+        break
+')
+
+text="${capacity}%"
+[[ -n "$power" ]] && text+=" (${power}W)"
+
+icons=("󰁺" "󰁼" "󰁾" "󰂀" "󰁹")
+if [[ "$status" == "Charging" ]]; then
+  icon="󰂄"
+else
+  idx=$((capacity * ${#icons[@]} / 101))
+  icon="${icons[$idx]}"
+fi
+
+class="normal"
+if [[ "$status" != "Charging" ]]; then
+  if ((capacity <= 15)); then
+    class="critical"
+  elif ((capacity <= 30)); then
+    class="warning"
+  fi
+fi
+
+printf '{"text": "%s %s", "class": "%s", "tooltip": "%s, %s"}\n' \
+  "$icon" "$text" "$class" "$status" "${power:+${power}W}"

config/waybar/style.css

@@ -12,9 +12,9 @@ window#waybar { background: @bg; color: @text; }
 #workspaces button.focused { color: @bg; background: @blue; }
 #workspaces button.focused:hover { background: @blue; color: @bg; }
 #workspaces button.urgent { background: @blue-dark; color: @text; }
-#mode, #clock, #cpu, #memory, #custom-network, #pulseaudio, #backlight, #battery, #tray, #custom-power { padding: 0 10px; margin: 4px 2px; background: transparent; border-radius: 6px; }
+#mode, #clock, #cpu, #memory, #custom-network, #pulseaudio, #backlight, #custom-battery, #tray, #custom-power { padding: 0 10px; margin: 4px 2px; background: transparent; border-radius: 6px; }
-#mode:hover, #clock:hover, #cpu:hover, #memory:hover, #custom-network:hover, #pulseaudio:hover, #backlight:hover, #battery:hover, #tray:hover, #custom-power:hover { background: @surface; }
+#mode:hover, #clock:hover, #cpu:hover, #memory:hover, #custom-network:hover, #pulseaudio:hover, #backlight:hover, #custom-battery:hover, #tray:hover, #custom-power:hover { background: @surface; }
 #clock { color: @blue; font-weight: bold; background: transparent; }
 #cpu, #memory { color: @text; }
 #custom-power { color: @blue; font-size: 16px; }
-#battery.warning, #battery.critical { color: @blue; }
+#custom-battery.warning, #custom-battery.critical { color: @blue; }