Yokogawa S9129FA Backup Battery Pack

Overview

The Yokogawa S9129FA Battery Pack is a Nickel-Metal Hydride (Ni-MH) rechargeable backup battery specifically engineered for use in Yokogawa industrial automation systems, including Distributed Control Systems (DCS) and programmable logic controllers (PLC). As a critical power backup component, the S9129FA ensures system memory, real-time clocks, and essential logic circuitry remain powered during mains failures, minimizing unplanned downtime and protecting process data. 

Originally manufactured by Yokogawa Electric Corporation, this compact battery pack delivers a stable 2.4 V DC output with approximately 1100 mAh capacity, ideal for long-term backup in mission-critical control systems. 

Design & Construction

Built to withstand industrial environments, the S9129FA features a robust Ni-MH cell construction that offers:

• Low self-discharge for extended standby readiness

• Consistent voltage delivery under varying load conditions

• Wide temperature tolerance, ensuring reliable performance in control cabinets and equipment rooms exposed to heat or fluctuating climates (commonly from −20 °C to +70 °C). 

Ni-MH chemistry also provides a safer alternative to older cell types, reducing the risk of leakage and extending service life when maintained properly.

Industrial Backup Power Functionality

In automated manufacturing plants, utility control centers, or process facilities, power interruptions—even momentary—can lead to data loss, unsynchronized PLC logic, or control failures. The S9129FA battery pack addresses this by providing:

• Uninterrupted memory retention

• Back-up for real-time clocks and system parameters

• Fail-safe retention of critical data during outages

  This ensures that sensitive systems such as PLCs, DCS consoles, and logic modules continue to operate correctly until mains power is restored.

Typical Applications

The Yokogawa S9129FA is widely used across a range of industrial automation environments:

• Process automation (chemical, oil & gas, power plants)

• Manufacturing control systems

• Distributed Control Systems (DCS) including Yokogawa CS1000 and CS3000

• PLC memory and logic backup modules

• Industrial automation racks and cabinets 

Whether integrated into new PLC builds or retrofitted into existing control hardware, this battery pack is essential for maintaining system reliability and safeguarding operational continuity.

Performance & Reliability

Thanks to its Ni-MH chemistry and rugged design, the S9129FA battery delivers dependable performance over extended service periods with minimal maintenance. Its low self-discharge characteristics help retain charge for lengthy durations when systems are offline, while its robust construction ensures resistance to vibration and standard industrial stresses.

FAQ

What is the Yokogawa S9129FA battery used for?

It serves as a backup power source for Yokogawa control systems such as CS1000 and CS3000, preserving memory and logic during power interruptions. 

What type of battery chemistry does it use?

The battery uses Nickel-Metal Hydride (Ni-MH) chemistry, offering stability and durability for industrial backup applications. 

What voltage and capacity does it have?

The S9129FA provides 2.4 V DC output with an approx. 1100 mAh capacity. 

Is this battery suitable for harsh environments?

Yes — it is designed to operate reliably over a wide temperature range and withstand typical industrial conditions. 

Call to Action

Request a quote or technical inquiry for the Yokogawa S9129FA Battery Pack to ensure your Yokogawa DCS/PLC system remains protected against power outages and operates with maximum uptime.