Hazard detection systems according to embodiments described herein are operative to provide failsafe safety detection features and user interface features using circuit topology and power budgeting methods that minimize power consumption. The safety detection features can monitor environmental conditions (e.g., smoke, heat, humidity, carbon monoxide, carbon dioxide, radon, and other noxious gasses) in the vicinity of the hazard detection system associated and alarm occupants when an environmental condition exceeds a predetermined threshold.