A rechargeable battery system that provides emergency power to run the elevator to the nearest floor and open doors during a mains power failure.
Full Definition
The battery backup system (also called ARD battery or UPS for elevator) stores energy in rechargeable batteries (typically lead-acid or lithium-ion) to provide emergency power when the main supply fails. Its primary function is the automatic rescue device (ARD): moving the stalled car to the nearest landing, opening the doors to release passengers, then shutting down. Secondary functions may include emergency lighting power and communication system backup. Battery capacity is sized for the number of rescue operations required and must be maintained by a trickle charger. Regular battery testing and replacement intervals are specified in the maintenance contract and EN 13015.
