Exit sign and emergency light batteries replace failing or expired batteries in compatible signs and lights to keep them functioning and compliant with local safety codes. Safety codes require monthly testing to reveal failing batteries, allowing for replacement before old batteries are completely dead. A trickle charge from AC power keeps the batteries ready to supply standby power to run signs and lights during a power outage. These OEM replacement batteries are not interchangeable. They are compatible with exit signs and emergency lights of a specific brand and model in order to fit properly, perform correctly, and maintain UL 294 compliance. Batteries at the end of their life cycle require disposal or recycling in accordance with state regulations.