A little script that disables bluetooth when the power cable is disconnected and enables it back when plugged in

BTbyPower.applescript

on idle
	set powerStatus to do shell script "pmset -g ps"
	
	tell application "System Preferences"
		reveal pane id "com.apple.preferences.Bluetooth"
		#activate
		tell application "System Events" to tell process "System Preferences"
			set btCheckBox to checkbox "On" of window 1
			if powerStatus contains "Battery Power" then
				tell btCheckBox
					if value is 1 then click
				end tell
			else
				tell btCheckBox
					if value is 0 then click
				end tell
			end if
		end tell
		quit
	end tell
	# check again in 15 seconds
	return 15
end idle