This sound is associated with WALL-E, Pixar’s 2008 animated film about the small waste-collecting robot. Online, creators commonly use the charge line and its dramatic ending for battery memes, solar jokes and recovery edits where someone goes from drained to fully powered. Its appeal comes from how clearly it communicates a full recharge in just a couple of seconds, while the extended final tone gives editors an easy moment for a visual reveal or punchline.