diff --git a/README.md b/README.md
index 31fa021..c0d079a 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 Collection of Bash scripts to execute functionalities in folders, such as optimizing videos, unzipping files, converting images, etc.
 
 - [Video optimizer](#video-optimizer)
+- [Battery hook](#battery-hook)
 - [Decompress files](#decompress-files)
 
 ---
@@ -102,6 +103,126 @@ Add to document.
 
 ---
 
+## Battery hook
+
+Folder with scripts to be launched in different battery states.
+
+The filename of the scripts must be:
+
+- `discharging`: When the battery is in use.
+- `charging`: When the battery is charging.
+- `low`: When it reaches the low percentage. Default 15.
+- `high`: When it reaches the high percentage. Default 85.
+- `full`: When the battery is full.
+
+They must have **execution permissions**. If any of them do not exist, they will be ignored.
+
+### Install
+
+
+``` sh
+curl -o bash-folders-battery-hook https://raw.githubusercontent.com/tanrax/bash-folders/main/bash-folders-battery-hook.sh && chmod +x bash-folders-battery-hook && sudo mv bash-folders-battery-hook /usr/local/bin && echo "🎉 Successfully installed! 🎉"
+```
+
+Test
+
+``` sh
+bash-folders-battery-hook --help
+```
+
+### Run
+
+``` sh
+bash-folders-battery-hook --folder [folder path]
+```
+
+Example.
+
+``` sh
+mkdir battery-scripts
+
+touch battery-scripts/discharging
+chmod +x battery-scripts/discharging
+touch battery-scripts/charging
+chmod +x battery-scripts/charging
+touch battery-scripts/low
+chmod +x battery-scripts/low
+touch battery-scripts/high
+chmod +x battery-scripts/high
+touch battery-scripts/full
+chmod +x battery-scripts/full
+
+bash-folders-battery-hook --folder battery-scripts
+```
+
+### Start at operating system startup
+
+#### Option 1: Service
+
+Create a file in `/etc/systemd/system/bash-folders-battery-hook.service` with the following content.
+
+
+```ini
+[Unit]
+Description=Folder with scripts to be launched in different battery states.
+
+[Service]
+Restart=always
+RestartSec=5
+User=[user]
+ExecStart=bash-folders-battery-hook --folder [folder path]
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Edit it to your needs.
+
+Now you will need the script to run every so often to check the battery status. The best solution is to create a `timer`.
+
+Create a file in `/etc/systemd/system/bash-folders-battery-hook.timer` with the following content.
+
+```ini
+[Unit]
+Description=Folder with scripts to be launched in different battery states every minute.
+
+[Timer]
+OnCalendar=*-*-* *:*:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target
+```
+
+Recharge services.
+
+``` sh
+sudo systemctl daemon-reload
+```
+
+And activate it.
+
+``` sh
+sudo systemctl enable bash-folders-battery-hook.timer
+sudo systemctl start bash-folders-battery-hook.timer
+```
+
+#### Option 2: Cron
+
+Open.
+
+``` sh
+crontab -e
+```
+
+Add to document.
+
+``` sh
+@reboot * * * * * bash-folders-battery-hook --folder [folder path]
+```
+
+---
+
 ## Development
 
 ### Check syntax
diff --git a/bash-folders-battery-hook.sh b/bash-folders-battery-hook.sh
new file mode 100644
index 0000000..6105a78
--- /dev/null
+++ b/bash-folders-battery-hook.sh
@@ -0,0 +1,117 @@
+#!/usr/bin/env bash
+
+# --
+# Description: Script that launches other scripts in different battery states.
+# --
+# Cron: * * * * *  bash-folders-battery-hook.sh --folder [folder path]
+# --
+
+#cat /sys/class/power_supply/BAT0/capacity
+
+#cat /sys/class/power_supply/BAT0/status
+
+#Discharging
+#Charging
+#Full
+
+#xrandr --output eDP --brightness 1
+
+
+# START
+set -e
+
+# VARIABLES
+PROGNAME=$(basename "$0")
+FOLDER_ORIGIN="$2"
+LOW_BATTERY=15
+HIGH_BATTERY=85
+
+# FUNCTIONS
+
+usage() {
+    if [ "$*" != "" ] ; then
+        echo "Error: $*"
+    fi
+
+    cat << EOF
+Usage: $PROGNAME [OPTION]
+Script that launches other scripts in different battery states.
+  "discharging" When the battery is in use.
+  "charging" When the battery is charging.
+  "low" When it reaches the low percentage. Default 15.
+  "high" When it reaches the high percentage. Default 85.
+  "full" When the battery is full.
+
+Options:
+--folder [path]  Folder where the different scripts are located.
+--help           Display this usage message and exit
+EOF
+
+    exit 1
+}
+
+send-notification() {
+    if command -v notify-send >/dev/null 2>&1; then
+	# Send a native notification
+	notify-send "$1"
+    else
+	# If the above command is not available, print by console
+	echo "$1"
+    fi
+
+}
+
+start() {
+    # Monitors the selected folder
+    inotifywait -m -e create,moved_to --format '%f' "$FOLDER_ORIGIN" |
+	while read -r filename; do
+	    # Gets the file extension
+	    extension="${filename##*.}"
+	    # Checks if the extension is in the extension list
+	    for ext in "${EXTENSIONS_TO_WATCH[@]}"; do
+		if [[ "$ext" = "$extension" ]]; then
+		    # Check if the file name starts with "optimized"
+		    if [[ "$filename" != optimized* ]]; then
+		    	filename_output="optimized_${filename%.*}.mp4"
+			# Notifies that the conversion is to be started
+			send-notification "Optimizing $filename_output ..."
+			# Displays a flat file of information
+			touch "$FOLDER_ORIGIN/$MESSAGE_WAITING"
+			# Convert the file to MP4 format using ffmpeg in /tmp/
+			ffmpeg -i "$FOLDER_ORIGIN/$filename" -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -nostdin -shortest "/tmp/$filename_output"
+			# When finished move the optimized file
+			mv "/tmp/$filename_output" "$FOLDER_ORIGIN/$filename_output"
+			# Notifies that it has been terminated
+			send-notification "Completed! Output: $filename_output"
+			# Remove a flat file of information
+			rm "$FOLDER_ORIGIN/$MESSAGE_WAITING"
+		    fi
+		fi
+	    done
+	done
+}
+
+# CONTROLE ARGUMENTS
+isArg=""
+
+while [ $# -gt 0 ] ; do
+    case "$1" in
+    --help)
+        usage
+        ;;
+    --folder)
+        isArg="1"
+	if [ $# -eq 2 ]; then
+	    start
+	else
+	    usage "You need to specify the path of the folder to watch."
+	fi
+        ;;
+    *)
+    esac
+    shift
+done
+
+if [ -z $isArg ] ; then
+    usage "Not enough arguments"
+fi