ISO 7176-25:2022/Amd 1:2025

Overview

ISO 7176-25:2022/Amd 1:2025 is the latest amendment to the international standard concerning lead-acid batteries and chargers for powered wheelchairs. Published by the International Organization for Standardization (ISO), this amendment updates key requirements and test methods related to the charging voltage ranges and rated DC output voltages for powered wheelchair battery chargers. The document ensures safety, performance, and reliability in wheelchair power systems through clearly defined technical specifications.

This amendment specifically sets tolerances for charger output voltage and provides precise calculations for the minimum and maximum absorption phase voltages during testing. It emphasizes consistency in charger performance under nominal mains voltage variations, which is critical to extend battery life and maintain wheelchair usability.

Key Topics

• Charging Voltage Range
  The charger must supply an output voltage within ±2.0% of the manufacturer’s specified output, even when the input mains voltage fluctuates ±6%. This ensures stable voltage delivery during typical household or healthcare facility power supply variations.

• Rated DC Output Voltage
  The amendment establishes how to record the rated DC output voltage (U_chg) and defines:

  • The minimum absorption phase voltage as 98% of the minimum rated output voltage.
  • The maximum absorption phase voltage as 102% of the maximum rated output voltage.

• Battery Capacity and Charger Output Current
  The standard requires documentation of the maximum battery capacity (C) specified by the manufacturer. The test output current for the charger is defined as 50% of the minimum rated current (I_chg,min), ensuring realistic conditions during testing.

• Test Method Updates
  Precise mathematical formulas for voltage and current calculations support standardized testing procedures, enabling manufacturers and testing laboratories to validate charger compliance reliably.

Applications

• Powered Wheelchair Manufacturers
  Ensures that lead-acid batteries and chargers supplied as part of powered wheelchair systems meet consistent quality and safety margins, improving user confidence and regulatory compliance.

• Battery Charger Designers and Developers
  Provides clear parameters for charger output voltage tolerances and performance characteristics, guiding design for optimal charging cycles and battery life extension.

• Testing Laboratories and Certification Bodies
  Offers standardized test methods for verifying charger output voltage ranges and current requirements, facilitating objective assessments and certifications.

• Healthcare Providers and Maintenance Services
  Supports maintenance protocols by defining charger specifications that protect wheelchair batteries from overcharge or undercharge, reducing downtime and costly replacements.

Related Standards

• ISO 7176 Series
  Part of the comprehensive ISO 7176 series, which addresses multiple aspects of wheelchair performance, safety, and testing-including dimensions, environmental testing, and power systems.

• IEC Standards on Batteries and Chargers
  Often harmonized with IEC electrotechnical standards for lead-acid battery testing and charger safety to align wheelchair component safety on a global scale.

• ISO/IEC Directives
  Outlines the editorial and procedural requirements for amendment development, ensuring consistency across ISO documents.

Keywords: ISO 7176-25 amendment, powered wheelchair batteries, lead-acid battery chargers, wheelchair charger voltage tolerance, wheelchair battery charger test methods, DC output voltage range, powered wheelchair battery standards, wheelchair charger performance, battery charger testing international standard, powered mobility device batteries.