A contemporary vape detector can run on battery power
https://www.benzinga.com/pressreleases/26/04/g52007204/zeptive-releases-update-1-33-500-for-vape-detectors-adds-enhanced-detection-performance-loitering-
A modern vape detector can operate on battery power, enabling flexible placement in toilets and locker rooms without pricey wiring or remodellings.