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Notifly Notifly

Battery notifications

When you’re working with an external monitor and the lid closed, it’s easy to miss that the power adapter disconnected — and in an hour the laptop will go to sleep. This can be solved with a single script.

Linux: systemd timer

Section titled “Linux: systemd timer”

Script ~/bin/notifly-battery:

#!/usr/bin/env bash
set -eu
set -a; source ~/.notifly.env; set +a


LEVEL=$(cat /sys/class/power_supply/BAT0/capacity)
STATUS=$(cat /sys/class/power_supply/BAT0/status)
STATE_FILE=/tmp/notifly-battery.state
PREV=$(cat "$STATE_FILE" 2>/dev/null || echo "Full:100")


PREV_STATUS="${PREV%%:*}"
PREV_LEVEL="${PREV##*:}"


send() {
    ~/bin/notifly-send "$1" "$2" "$3"
}


# Low battery (only when discharging).
if [[ "$STATUS" == "Discharging" ]]; then
    if (( LEVEL <= 5 ))  && (( PREV_LEVEL > 5 ));  then send "🪫 Батарея 5%" "Срочно подключайте зарядку!" 9; fi
    if (( LEVEL <= 15 )) && (( PREV_LEVEL > 15 )); then send "🔋 Батарея 15%" "Скоро понадобится зарядка." 6; fi
    if (( LEVEL <= 30 )) && (( PREV_LEVEL > 30 )); then send "🔋 Батарея 30%" "Заряд снижается." 3; fi
fi


# AC status change (adapter disconnected/connected).
if [[ "$STATUS" != "$PREV_STATUS" ]]; then
    case "$STATUS" in
        Discharging) send "⚡ Зарядка отключена" "Текущий уровень: ${LEVEL}%" 5 ;;
        Charging)    send "🔌 Зарядка подключена" "Текущий уровень: ${LEVEL}%" 2 ;;
        Full)        send "✅ Батарея 100%" "Можно отключать." 3 ;;
    esac
fi


echo "$STATUS:$LEVEL" > "$STATE_FILE"

Make it executable and set up a systemd timer to run every 60 seconds:

~/.config/systemd/user/notifly-battery.service
[Unit]
Description=Notifly battery check


[Service]
Type=oneshot
ExecStart=%h/bin/notifly-battery
~/.config/systemd/user/notifly-battery.timer
[Unit]
Description=Run notifly-battery every minute


[Timer]
OnBootSec=2min
OnUnitActiveSec=60s


[Install]
WantedBy=timers.target
Окно терминала
systemctl --user daemon-reload
systemctl --user enable --now notifly-battery.timer

macOS: launchd + pmset

Section titled “macOS: launchd + pmset”
~/bin/notifly-battery
#!/usr/bin/env bash
set -eu; set -a; source ~/.notifly.env; set +a
LEVEL=$(pmset -g batt | grep -Eo "[0-9]+%" | head -1 | tr -d '%')
SRC=$(pmset -g batt | head -1 | grep -Eo "AC|Battery")
STATE=/tmp/notifly-battery.state
PREV=$(cat "$STATE" 2>/dev/null || echo "AC:100")
# ... same logic as for Linux
echo "$SRC:$LEVEL" > "$STATE"

~/Library/LaunchAgents/com.notifly.battery.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
                       "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>            <string>com.notifly.battery</string>
  <key>ProgramArguments</key> <array><string>/Users/you/bin/notifly-battery</string></array>
  <key>StartInterval</key>    <integer>60</integer>
</dict>
</plist>

launchctl load ~/Library/LaunchAgents/com.notifly.battery.plist.

Windows: PowerShell + Task Scheduler

Section titled “Windows: PowerShell + Task Scheduler”
C:\scripts\Notifly-Battery.ps1
$ErrorActionPreference = "Stop"
$cfg = Get-Content "$env:USERPROFILE\.notifly.json" | ConvertFrom-Json
$bat = (Get-CimInstance Win32_Battery)
$level = $bat.EstimatedChargeRemaining
$onBattery = ($bat.BatteryStatus -eq 1)


$state = "$env:TEMP\notifly-bat.txt"
$prev  = if (Test-Path $state) { Get-Content $state } else { "AC:100" }
$prevLevel = [int]($prev.Split(":")[1])


function Send($title, $msg, $pri) {
  Invoke-RestMethod -Method Post -Uri "$($cfg.url)/message?token=$($cfg.token)" `
    -ContentType "application/json" `
    -Body (@{ title = $title; message = $msg; priority = $pri } | ConvertTo-Json)
}


if ($onBattery) {
  if ($level -le 5  -and $prevLevel -gt 5)  { Send "🪫 Батарея 5%"  "СРОЧНО!" 9 }
  if ($level -le 15 -and $prevLevel -gt 15) { Send "🔋 Батарея 15%" "Подключите зарядку." 6 }
}
"$(if($onBattery){'BAT'}else{'AC'}):$level" | Set-Content $state

In Task Scheduler — run every minute as your user.

Benefits

Section titled “Benefits”
  • You won’t lose a work day due to an accidental discharge.
  • You know when the power adapter disconnected — no need to move the laptop to check the indicator.
  • At priority 9 the push arrives even in DND.

Further improvements

Section titled “Further improvements”
  • Attach an estimate of remaining time to the message (pmset -g batt, upower -i).
  • Separate scripts for a laptop and for a computer with UPS.