Building fire smoke exhaust fans and fire escape access doors are linked evacuation devices, equipped with lead-acid batteries as dedicated backup power. After fire power cuts, batteries supply power rapidly to unlock fire escape doors and start exhaust fans, removing toxic smoke and opening safe evacuation passages. Valve-regulated lead-acid batteries have automatic pressure relief function; safety valves exhaust air automatically to avoid rupture under high internal pressure, suitable for closed fire air duct environments. Modular installation facilitates old building fire renovation, with easy maintenance and unattended operation, meeting standard fire linkage power supply requirements.