A modern vape detector can run on battery power

https://www.fox4kc.com/business/press-releases/globenewswire/9676076/zeptive-software-update-boosts-vape-detection-performance-and-adds-new-features-free-update-for-all-customers-with-zeptives-custom-communications-module

A modern vape detector can operate on battery power, making it possible for flexible placement in bathrooms and locker rooms without pricey wiring or remodellings.