My macbook air is getting old, so the battery is rather unreliable. This means I have to keep it constantly charged, or my computer may shut down suddenly as the battery plummets. But the charger is also old, and so sometimes if i shift the computer around it disconnects suddenly without my knowledge. Is there a way to set an audio alarm for when the computer disconnects from the charger? The only solutions online i found are for when the battery gets low, which may not occur because the battery drops and raises its percentage without warning, or unavailable in singapore.