Alarm Grid uses many kinds of batteries. There is not a single universal battery type that is used with all Alarm Grid equipment. The type of battery that is used with a particular security device will typically depend upon the size of the hardware and its unique power supply needs. Simply put, a battery is a power supply. A battery can be the primary power source of a device, or it can be a backup that is designed to keep device powered when the electricity goes out. Almost every piece of security equipment will use some type of battery, including control panels, sensors, keypads and more. However, a notable exception to this general rule is security cameras, which wouldn't benefit greatly from battery power. It's somewhat difficult to generalize batteries because there are so many different setups and situations where they are used with security systems. But there are a few common principles that often apply. For one, most wireless security sensors use batteries as their primary source of power. This eliminates the need for running a power cord to the sensor, and it gives the user greater flexibility in mounting the device. These batteries are almost always non-rechargeable, and they will need to be replaced every few years. The good news however is that the sensor will continue to function exactly as normal when the power goes out. But on the other hand, most control panels and keypads use batteries as a backup source of power. These devices will primarily use plug-in electrical power and only switch over to battery power when the electricity is out. Unlike the batteries used with wireless security sensors, the backup batteries used with panels are usually rechargeable. These backup batteries will be slowly storing power when the panel is running on electrical power to prepare for a situation when the power is out. But these batteries will still need to be replaced every several years. When a sensor or a security panel has a low-battery, the system will typically display a trouble condition to let the user know of the problem. When this happens, the user should take steps to replace the battery as soon as possible to prevent any sort of power loss or failure. The exact type battery that is used will vary between different sensors and panels. Some of the most common battery types used with security equipment include CR123A batteries, CR2025 coin batteries and AA batteries. We usually recommend using lithium batteries over alkaline batteries, since they tend to keep devices powered for longer periods of time and function more reliably. Please check out our battery page for more batteries offered from Alarm Grid.