Alarm control unit batteries are usually rechargeable sealed lead-acid batteries. Manufacturers recommend replacing these batteries every four (4) to five (5) years. As batteries age, their standby power capacity gradually diminishes, justifying the 4-5 year replacement interval. Many systems employ detection equipment like motion detectors, smoke detectors, and door contacts that feature internal batteries. The lifespan of these batteries largely depends on factors like motion activity or door usage. Fortunately, these devices monitor their batteries, often signaling a low battery state, while remaining operational for at least an additional thirty days.