The Directed 520T is a battery back up system for your security system. It includes an advanced charging/trigger module that will send a negative trigger to your security system alerting you if/when the main vehicle battery is disconnected from your security system. The advanced charger circuitry keeps the battery pack fully charged at all times.
Keep 12 volt power to your security system even if your vehicle battery is cut, or goes dead. This optional back-up battery adds to the security of any install, maintaining power delivery to your security system even if would-be thieves try to silence the siren by disconnecting your vehicle battery.