PLC | Siemens | 6ES7971-1AA00-0AA0 6ES7 971-1AA00-0AA0 SIMATIC S7 Backup battery

Product Description: Siemens 6ES7971-1AA00-0AA0

The Siemens 6ES7971-1AA00-0AA0 is a dedicated lithium backup battery designed to maintain memory and real-time clock functions in SIMATIC S7-300 CPUs and legacy S5-90U controllers. Installed in the CPU’s battery compartment, it delivers a reliable 3.6 V supply at 0.85 Ah to preserve user programs, data and timekeeping during power outages or maintenance activities.

Key Features

• Chemistry: Lithium manganese dioxide primary cell
• Nominal Voltage: 3.6 V DC
• Capacity: 0.85 Ah (850 mAh)
• Form Factor: Cylindrical cell sized for direct clip-in into CPU battery holder
• Service Life: Designed for long-term backup — typical shelf life ≥ 10 years
• Operating Temperature Range: –25 °C … +70 °C
• Storage Temperature Range: –40 °C … +80 °C

Technical Specifications

• Nominal Voltage: 3.6 V DC
• Capacity: 0.85 Ah
• Continuous Discharge Current: ≤ 50 mA
• Pulse Discharge Capability: ≤ 200 mA (short-term peaks)
• Dimensions (Ø × Length): 20 mm × 50 mm (approximate)
• Weight: ≈ 15 g
• Shelf Life: ≥ 10 years (at 20 °C, 50 % RH)
• Protection Class: IP00 (installed within CPU module)

Application Areas

• Memory backup for SIMATIC S7-300 CPU modules during power failures
• Real-time clock retention in S7-300 and S5-90U controllers
• Prevention of program and data loss during maintenance or outages
• Industrial automation systems where reliable data retention is essential

Advantages

• Reliable Data Retention: Ensures uninterrupted memory and clock functions under all conditions
• Long Shelf Life: Lithium chemistry delivers a decade of standby readiness without replacement
• Wide Temperature Tolerance: Operates over extreme industrial temperature ranges
• Easy Replacement: Drop-in format matches CPU holder for fast service
• Cost-Effective: Minimizes costly program reloads and system downtime after power loss