BATTERY FAT and SAT Major Testing Components and Procedures Overview

June 22, 2024

Factory Acceptance Testing (FAT) vs. Site Acceptance Testing (SAT):
A Technical Comparison

Battery Factory Acceptance Testing, Symtech Solar

When it comes to ensuring the quality, performance, and reliability of energy storage battery systems, two critical phases stand out:  Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT).  FAT is conducted at the manufacturer’s facility before the equipment is shipped, while SAT takes place at the installation site after the equipment is installed.  These testing phases play a crucial role in verifying that the equipment meets specified design and performance criteria and operates correctly in its intended environment. Understanding the differences between FAT and SAT is essential for manufacturers, installers, and customers to ensure the successful deployment and operation of energy storage battery systems.

This article covers some of the major testing components and procedures of both.


  • FAT: Factory Acceptance Testing is a crucial pre-shipment procedure conducted at the manufacturer’s facility. It ensures that equipment meets design and performance specifications before delivery.
  • SAT: Site Acceptance Testing, on the other hand, is performed at the installation site to validate equipment performance in the actual operational environment.


  • FAT: Conducted at the manufacturer’s facility.
  • SAT: Conducted at the installation site.


  • FAT: Verifies equipment compliance with design and performance requirements.
  • SAT: Validates equipment performance and integration with existing systems.


  • FAT: Occurs before equipment shipment.
  • SAT: Occurs after equipment installation.


  • FAT: Focuses on equipment functionality, safety, and standards compliance.
  • SAT: Focuses on integration, performance validation, and site-specific conditions.


  • FAT: Involves manufacturer, customer, and potentially third-party inspectors.
  • SAT: Involves customer, installation team, and possibly third-party inspectors.

Test Environment:

  • FAT: Simulated environment at manufacturer’s facility.
  • SAT: Actual operational environment at installation site.


  • FAT: Results documented in FAT report.
  • SAT: Results documented in SAT report.

Issues Resolution:

  • FAT: Issues resolved before equipment shipment.
  • SAT: Issues must be resolved before equipment is considered operational.


  • FAT: Primarily manufacturer’s responsibility.
  • SAT: Primarily customer’s responsibility, with support from manufacturer or installation team.

Equipment Handling:

  • FAT: Manufacturer’s personnel handle equipment.
  • SAT: Customer’s personnel or installation team handles equipment.

Performance Validation:

  • FAT: Focuses on individual equipment performance.
  • SAT: Focuses on overall system performance and integration.



Factory Acceptance Testing (FAT) for Energy Storage Battery Systems


Factory Acceptance Testing (FAT) is a crucial phase in the production of energy storage battery systems. It ensures that the systems meet the specified design and performance criteria before they are delivered to the customer. This testing phase involves a series of comprehensive checks and evaluations conducted in the manufacturer’s facility. FAT verifies that the battery systems function correctly under various conditions and that they adhere to safety, performance, and reliability standards.

Objectives of FAT

The primary objectives of FAT for energy storage battery systems include:

  1. Verification of Design and Specifications: Ensuring the system meets the design specifications and performance requirements outlined in the contract.
  2. Functional Testing: Confirming that the system operates correctly under different conditions and scenarios.
  3. Safety Compliance: Verifying that the system complies with relevant safety standards and regulations.
  4. Quality Assurance: Identifying any defects or issues before the system is shipped to the installation site.

Key Components of FAT

FAT for energy storage battery systems typically includes the following components:

  1. Visual Inspection: Checking for physical damages, proper labeling, and adherence to design specifications.
  2. Electrical Testing: Verifying electrical performance, including voltage, current, and capacity measurements.
  3. Functional Testing: Evaluating the system’s response to various operational scenarios, such as charging, discharging, and emergency shutdowns.
  4. Safety Testing: Assessing safety features like overvoltage, overcurrent, short-circuit protection, and thermal management.
  5. Communication and Control Systems Testing: Ensuring that the system’s communication and control interfaces function correctly.
  6. Environmental Testing: Simulating environmental conditions such as temperature and humidity to ensure the system’s reliability and performance in real-world conditions.

Detailed FAT Procedures

1. Visual Inspection

  • Physical Condition: Inspect the battery system for any signs of physical damage or manufacturing defects.
  • Labeling and Documentation: Verify that all components are correctly labeled and that all necessary documentation is available and accurate.
  • Component Verification: Check that all components specified in the design are present and correctly installed.

2. Electrical Testing

  • Voltage and Current Measurements: Measure the voltage and current of the battery system to ensure they are within specified ranges.
  • Capacity Testing: Conduct tests to verify the actual capacity of the battery system compared to the specified capacity.
  • Impedance and Resistance Testing: Measure the internal impedance and resistance to ensure they are within acceptable limits.

3. Functional Testing

  • Charge and Discharge Cycles: Perform multiple charge and discharge cycles to evaluate the system’s performance and efficiency.
  • Response to Fault Conditions: Simulate fault conditions such as overvoltage, undervoltage, and short-circuits to verify the system’s protective measures.
  • Operational Scenarios: Test the system’s response to various operational scenarios, including normal operation, peak load, and emergency shutdown.

4. Safety Testing

  • Overvoltage Protection: Verify that the system can handle overvoltage conditions without failure.
  • Overcurrent Protection: Test the system’s ability to protect against overcurrent conditions.
  • Thermal Management: Evaluate the effectiveness of the system’s thermal management in preventing overheating and ensuring safe operation.
  • Short-Circuit Protection: Ensure that the system can safely handle and recover from short-circuit conditions.

5. Communication and Control Systems Testing

  • Interface Verification: Verify the functionality of all communication and control interfaces, including SCADA (Supervisory Control and Data Acquisition) systems.
  • Data Accuracy: Ensure that the data transmitted by the battery system is accurate and reliable.
  • Control Functions: Test all control functions, including remote operation, monitoring, and emergency shutdown commands.

6. Environmental Testing

  • Temperature Cycling: Subject the battery system to various temperature cycles to assess its performance in different thermal conditions.
  • Humidity Testing: Evaluate the system’s reliability and performance under different humidity levels.
  • Vibration and Shock Testing: Simulate transportation and operational vibrations and shocks to ensure the system’s durability.

Documentation and Reporting

Upon completion of FAT, a detailed report is generated, documenting all tests performed, results obtained, and any discrepancies or issues identified. This report is reviewed and approved by both the manufacturer and the customer. Any issues found during FAT must be resolved before the system is shipped to the installation site.


Factory Acceptance Testing is a critical step in ensuring the quality, safety, and reliability of energy storage battery systems. By conducting thorough and comprehensive FAT, manufacturers can identify and address potential issues early, ensuring that the systems delivered to customers meet the highest standards of performance and reliability. This not only enhances customer satisfaction but also helps in building trust and credibility in the rapidly growing field of energy storage solutions.



Site Acceptance Testing (SAT) for Energy Storage Battery Systems: A Comprehensive Guide

Site Acceptance Testing (SAT) is a critical phase in the deployment of energy storage battery systems.  After passing Factory Acceptance Testing (FAT) and being installed at their final location, SAT ensures these systems perform optimally in their actual operational environment.  This testing phase verifies correct installation, seamless integration with existing infrastructure, and compliance with performance, safety, and reliability criteria under site-specific conditions.

Objectives of SAT

SAT for energy storage battery systems aims to:

  • Verify Installation:  Ensure the system is installed according to specifications and standards.
  • Perform Integration Testing:  Confirm integration with the site’s electrical and control systems.
  • Validate Performance:  Ensure the system operates as expected in its operational environment.
  • Ensure Safety and Compliance:  Verify compliance with local safety standards and regulations.
  • Achieve Customer Satisfaction:  Demonstrate the system’s functionality and performance to the customer.

Key Components of SAT

SAT typically includes:

  1. Visual and Mechanical Inspection:  Check physical installation and mechanical integrity.
  2. Electrical Testing:  Verify electrical connections and performance.
  3. Functional Testing:  Evaluate performance under various scenarios.
  4. Safety Testing:  Ensure safe operation under all conditions.
  5. Communication and Control Systems Testing:  Test integration with control systems.
  6. Environmental Testing:  Assess performance under site-specific conditions.

Detailed SAT Procedures

  1. Visual and Mechanical Inspection:

    • Verify correct installation according to design specifications.
    • Check for physical damage from transportation and installation.
    • Ensure correct labeling and documentation.
  2. Electrical Testing:

    • Confirm all electrical connections are correct and secure.
    • Measure insulation resistance to detect faults.
    • Verify voltage and current levels are within specified ranges.
  3. Functional Testing:

    • Test responses to various operational scenarios.
    • Perform charge and discharge cycles to evaluate efficiency and capacity.
    • Simulate fault conditions to test protective measures and recovery capabilities.
  4. Safety Testing:

    • Ensure the system can handle overvoltage and overcurrent conditions.
    • Verify thermal management effectiveness.
    • Test emergency shutdown procedures.
  5. Communication and Control Systems Testing:

    • Verify all communication and control interfaces function correctly.
    • Ensure data transmitted by the system is accurate and reliable.
    • Test all control functions, including remote operation and monitoring.
  6. Environmental Testing:

    • Assess performance under local temperature conditions.
    • Verify performance under local humidity levels.
    • Evaluate performance in site-specific conditions.


Site Acceptance Testing is crucial for the successful deployment and operation of energy storage battery systems.  Through comprehensive SAT, installers can verify that systems operate correctly in real-world environments, meeting performance, safety, and reliability standards. This ensures customer satisfaction and long-term operational success.

In conclusion, Battery FAT (Factory Acceptance Testing) and SAT (Site Acceptance Testing) are vital processes in ensuring the quality and performance of battery energy storage systems (BESS). These tests, which encompass functional, performance, safety, environmental, and grid compatibility aspects, are essential for verifying compliance with specifications and standards. By conducting thorough FAT and SAT, manufacturers and operators can ensure that BESSs meet their intended requirements and operate reliably in their respective environments, contributing to the advancement and sustainability of energy storage solutions.