Indicator light devices are useful in many applications for indicating properties of physical spaces respectively associated therewith and in physical proximity thereto. The indicator light devices are network-enabled and self-powered, and capable of participating in coordinated power-managed operation to provide a sufficient service life and lower installation and replacement costs. The indicator light devices may be used with or without associated sensors. The various embodiments described herein use various power management techniques singly or in combination to greatly increase the service life of self-power indicator light devices without diminishing their effectiveness in the application. These techniques include operating only the indicator light devices associated with the physical spaces having properties of interest, operating the indicator light devices with synchronized flashing, operating the indicator light devices in accordance with the detection of specific conditions, relevant time operation, in-vicinity activation, and ambient light responsiveness.