multi-family properties

Emergency lights typically have a battery back-up that will operate the light in the event the power goes out, regardless of if there’s a generator for back-up power. Exit signs can and should also have a battery, especially if the building doesn’t have generator. Often during fire department inspections, they check that your emergency lights are operational, both with and without power. Emergency lights must be kept properly maintained to meet all federal and state requirements, so when installing new ones or updating old ones, should you just change the battery or replace the entire fixture?