Overview
ISO 24195:2022 - Road vehicles - Vocabulary and characteristics for engineering of starting devices - provides a harmonized vocabulary and a framework of characteristic descriptions for starter motors used in internal combustion engine (ICE) vehicles. Rather than prescribing test methods, this ISO standard defines common terms, their interdependencies and the general and special characteristics that are essential for starter motor engineering and communication across development, testing and supply-chain teams.
Key topics and technical focus
This document organizes and clarifies terminology and characteristic concepts that underpin starter motor design and testing, including:
- Core vocabulary: precise definitions for components and phenomena such as armature, battery, solenoid (engagement relay), pinion, ring gear, meshing spring, overrunning clutch, plunger, driveshaft, yoke.
- Functional terms: cranking, cranking time, first ignition, overrunning, starter motor ON time, starter motor disengagement speed.
- Electrical and mechanical parameters: starter motor current (ISTR), starter motor voltage (USTR), inrush current, lock (stall) current and lock (stall) torque, starter motor energy (ESTR), minimum and nominal battery voltage.
- General characteristics: component relationships and how engagement and disengagement are achieved (helical spline, meshing spring, solenoid action).
- Special characteristics:
- Magnetic field types: permanent magnet vs wound-field starter motors and their behavior (field constancy vs current-dependent field).
- Connection methods: series and parallel field connections and typical voltage uses (series often at 24 V, parallel often at 12 V).
- Performance aspects: starting performance, torque-speed relationships, energy consumption and starting parameters (cranking and overrunning times).
- Practical design notes: guidance on common configurations such as permanent magnet types typically used below 2 kW and wound-field types typically used above 2 kW.
Applications and users
ISO 24195:2022 is intended to improve clarity and efficiency across multidisciplinary projects and international teams. Typical users and applications include:
- Starter motor designers and electrical/mechanical engineers - for consistent terminology during design reviews and specifications.
- OEMs and Tier‑1 suppliers - to align requirements, procurement documents and technical interfaces.
- Test labs and validation engineers - for consistent reporting of starting parameters (inrush current, cranking time, starter energy).
- Technical writers, training organizations and newcomers - to learn standardized definitions and reduce ambiguity in documentation.
- Cross‑functional project teams (controls, battery systems, start/stop systems) - to harmonize communication across domains.
Related standards
- ISO 20574:2019 (referenced for some term sources)
- ISO 8856:2014 (referenced for stall torque terminology)
- ISO/IEC Directives (editorial framework for ISO documents)
ISO 24195:2022 is a practical vocabulary and characteristics reference that supports clearer engineering communication, better-aligned testing and reduced inefficiencies in starter motor development and start/stop system projects. Keywords: ISO 24195:2022, starter motor vocabulary, starting devices, starting parameters, cranking time, inrush current, permanent magnet starter, wound-field starter.
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