Central Battery System

Hi all,
On a project we have a non-maintained Central Battery System which supplies power to some of the luminaires in the space. It has been noticed that the system will work only if there a power shutdown while the respective emergency light fittings will not operate in a local circuit failure. As this is against the standards, a proposal was made to install contactors after all lighting circuits CPD so when a circuit failure happens, all the EM lights will go on.
Do you know if there is any other more efficient way of dealing with this issue?
Many thanks