Allen-Bradley SLC 500 Replacement Battery Assembly | 1747-BA

Functional Overview

The 1747-BA (Part Number: 1747-BA) is a specialized Lithium backup battery designed specifically for the Allen-Bradley SLC 500 processor series. This assembly is critical for maintaining the volatile memory (RAM) of the PLC, ensuring that the application program, register data, and internal clock settings are preserved during power-down cycles. Given the critical nature of industrial data retention, this high-energy density cell is engineered for a long shelf life and stable voltage discharge across varying industrial temperatures.

Detailed Technical Specifications

The following specifications define the electrical and mechanical properties of the 1747-BA assembly. Note: Some legacy documentation may conflate controller power draw with the battery itself; the battery is a standalone DC power source for memory retention.

• Chemistry: Lithium Thionyl Chloride ($Li-SOCl_2$)

• Nominal Voltage: 3.0 VDC

• Product Weight: 0.03 kg (0.06 lbs)

• Compatibility: SLC 5/01, 5/02, 5/03, 5/04, and 5/05 Processors

• Operating Temperature Range: 0°C to 60°C (32°F to 140°F)

• Storage Temperature: -40°C to 85°C (-40°F to 185°F)

• Connection Type: Polarized wire lead with proprietary 2-pin connector

Maintenance and Application FAQ

When should the battery be replaced?

The SLC 500 CPU will trigger a "BATT" LED indicator on the front panel when the voltage drops below a safe threshold. It is recommended to replace the 1747-BA while the PLC is powered on to prevent memory loss, or within 30 minutes of power-down if a capacitor backup is present.

What is the typical lifespan of the assembly?

While variables like ambient temperature and power-off duration affect longevity, the typical service life is 2 to 5 years under standard operating conditions.

How does this differ from the 1769-BA?

The 1747-BA is specifically for the SLC 500 (1747) family, whereas the 1769-BA is designed for CompactLogix (1769) controllers. They are not physically or electrically interchangeable due to different connector types.

Installation Guidelines

To ensure continuous operation, the battery should be installed into the designated socket located behind the processor door. Ensure the polarity-keyed connector is firmly seated. Disposal should follow local environmental regulations for Lithium-based hazardous waste.