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Reliable Power Backup for S7-300 and S7-400 PLC Systems
The Siemens 6ES7971-0BA02 backup battery provides essential power retention for SIMATIC S7-300 and S7-400 programmable logic controllers. This lithium battery maintains the contents of the CPU’s RAM memory during main power outages. It ensures that critical program data, user programs, and system parameters remain intact without any loss. The battery fits seamlessly into the designated compartment on the CPU module or the memory card slot.
This replacement battery comes as a complete unit with an integrated connector, which simplifies the installation process. Users can swap the battery while the PLC remains operational without interrupting active processes. The battery features a nominal voltage of 3.6 V and delivers a typical capacity of 2.3 Ah. This capacity supports extended backup times, which depend on the specific CPU type and memory configuration. For example, it can retain data for over 300 days under normal operating conditions.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Siemens |
| Model | 6ES7971-0BA02 |
| Product Category | Backup Battery |
| Battery Type | Lithium (Non-rechargeable) |
| Nominal Voltage | 3.6 V DC |
| Capacity | 2.3 Ah |
| Dimensions | 20 mm x 30 mm x 45 mm |
| Weight | Approx. 50 g |
| Compatibility | S7-300, S7-400, M7-300, M7-400 |
| Service Life | Up to 10 years |
| Operating Temperature | 0 °C to 60 °C |
| Storage Temperature | -20 °C to 50 °C |
| Shelf Life | Minimum 5 years |
| Connector Type | Integrated 2-pin plug |
The Siemens 6ES7971-0BA02 uses high-quality lithium chemistry, which guarantees stable voltage output throughout its service life. Its compact dimensions allow easy storage in spare parts inventories without occupying much space. This battery’s long shelf life of up to 5 years minimizes the risk of premature depletion before installation. Operators can monitor the battery status through the CPU’s diagnostic buffer, which provides timely warnings for replacement. The module supports hot-swapping, so maintenance teams can replace the battery during runtime without stopping critical processes. This feature proves especially valuable for continuous production lines where downtime costs remain prohibitively high. The battery’s 3.6 V output matches the exact requirements of SIMATIC memory modules. It provides consistent power delivery even under fluctuating ambient temperatures. Many industrial facilities stock this battery as a standard spare for their S7-300 and S7-400 systems. Its reliable performance ensures that valuable automation programs remain secure for years of operation.