Siemens 6ES7971-0BA00 SIMATIC S7-400 Backup Battery 3.6V/2.3AH PLC Accessory

The Siemens 6ES7971-0BA00 is a 3.6 V, 2.3 Ah backup battery for the SIMATIC S7-400 power supply modules PS 405 (4 A/10 A/20 A) and PS 407 (4 A/10 A/20 A). It replaces the depleted backup cell inside these power supplies to maintain retentive memory during a mains interruption. Net weight is 25 g, and it ships from Germany.

Technical Specifications

Selection Notes

This battery is specified for the PS 405 and PS 407 supply families across their 4 A, 10 A and 20 A current ratings — the accessory listing ties it exclusively to S7-400 power supplies, not to other SIMATIC rack generations. Replace it as routine maintenance on an existing PS 405 or PS 407 unit rather than as a spare for a different power supply type.

Applications

Used inside SIMATIC S7-400 racks equipped with a PS 405 or PS 407 power supply, where the backup cell needs periodic replacement to keep the power supply's buffering function intact through mains interruptions.