Product Overview

The Allen-Bradley 1756-BA2​ is a critical, genuine 3-volt lithium memory backup battery designed specifically for the ControlLogix programmable automation controller (PAC) platform and other compatible modules within the Allen-Bradley 1756 system. This battery serves a single, vital function: to provide auxiliary power to the controller’s volatile memory (RAM) in the event of a primary power loss. When the main power supply to the ControlLogix chassis is disconnected or fails, the 1756-BA2​ seamlessly takes over, preserving the controller’s user program, all data table values (including accumulated values of timers and counters, integer files, and other critical process data), and the system’s real-time clock. Without this battery, a power cycle would result in a complete memory wipe, forcing a time-consuming program download from a backup and the potential loss of valuable production or process data, leading to extended downtime and re-initialization efforts.The 1756-BA2​ is a drop-in replacement battery, engineered to the exact physical and electrical specifications required by the battery holder on the ControlLogix CPU module (such as the 1756-L6x series) and certain communication or specialty modules. It is not a standard consumer-grade coin cell; it is an industrial component selected for its stable discharge characteristics, extended shelf life, and reliability in the temperature ranges encountered in control panels. The value of the genuine Allen-Bradley 1756-BA2​ lies in its role as an inexpensive but crucial insurance policy. Its proactive, scheduled replacement is a fundamental part of preventative maintenance for any ControlLogix-based system, safeguarding the intellectual property embedded in the control logic and ensuring a rapid, predictable recovery from unexpected power outages, thereby protecting production continuity and operational efficiency.

Technical Specifications

Main Features and Advantages

Guaranteed Compatibility and Fit: The primary advantage of the genuine Allen-Bradley 1756-BA2​ is its assured perfect fit and electrical performance within the designated battery compartment on ControlLogix hardware. Using a non-specified battery risks physical incompatibility (wrong size or connector), incorrect voltage, or insufficient capacity, which could lead to poor contact, memory loss, or in extreme cases, damage to the module’s battery circuitry. The 1756-BA2​ is designed to snap securely into place, ensuring reliable electrical contact for the life of the battery.Extended Life and Industrial Reliability: This lithium battery is engineered for the long-term, low-current-draw application of memory backup. It offers a very low self-discharge rate and a long operational life, typically rated for several years of service in a powered chassis (where it is only used during power loss) and an even longer shelf life. Its wide operating temperature range ensures reliable performance in both cold and hot control panel environments, where consumer-grade batteries might fail prematurely. This industrial-grade reliability is essential for a component that may sit idle for years but must function flawlessly the one critical moment it is needed.Critical for System Integrity and Uptime: The 1756-BA2​ is a small component with an outsized impact on system availability. By preserving the control program and data during a power outage, it allows the ControlLogix system to resume operation immediately upon power restoration without requiring intervention from a programmer. This capability is crucial for continuous process industries and automated manufacturing lines where restarting from a blank state would involve a lengthy and error-prone manual initialization. Proactively replacing the Allen-Bradley 1756-BA2​ on a scheduled basis (e.g., every 2-3 years) is one of the most cost-effective maintenance actions to prevent unexpected, costly downtime and data loss.