BS EN 50604-1 - Battery Design

BS EN 50604-1 (the British Standard adoption of European Standard EN 50604-1) Secondary Lithium Batteries for Light EV (Electric Vehicle) Applications: Part 1: General Safety Requirements and Test Methods. This specifies safety requirements and test procedures for removable secondary lithium-ion battery packs and systems intended as traction batteries in light electric vehicles (LEV). It is published by CENELEC (European Committee for Electrotechnical Standardization) and adopted in the UK by the British Standards Institution (BSI). The standard was first published in 2016 and updated by Amendment 1 in 2021.

Published by: CENELEC (European Committee for Electrotechnical Standardization); adopted in the UK by BSI as BS EN 50604-1

Current edition: EN 50604-1:2016+A1:2021 (BS EN 50604-1:2016+A1:2021) is a consolidated version published 31 August 2021

First edition: EN 50604-1:2016 (BS EN 50604-1:2016)

Scope

EN 50604-1 covers voltage class A and voltage class B removable secondary lithium-ion battery packs and systems used as traction batteries in electrically propelled road vehicles of categories L1 to L7 (as defined under UNECE), and electrically assisted cycles (EPACs / e-bikes), including plug-in hybrid road vehicles (PHEVs) within these categories.

The standard addresses safety performance during intended vehicle use. It does not cover:

Individual cells (cell-level testing is outside scope)
Stationary energy storage applications
Vehicle repair or maintenance procedures
Primary (non-rechargeable) batteries
Non-lithium battery chemistries
Batteries covered by ISO 12405 (higher-voltage automotive traction batteries)

For e-bikes (EPACs), EN 50604-1 has become the primary battery safety standard; Amendment A1:2021 removed the earlier reference to EN 62133 for this application, making EN 50604-1 the sole standard for EPAC battery safety compliance under EN 15194.

Key Requirements and Test Methods

The standard defines safety criteria under electrical, mechanical, environmental, thermal, and system-level test categories. The primary safety criteria for most tests are: no fire, no explosion, no electrolyte leakage, and no dangerous venting.

Electrical Tests

Overcharge protection: Battery is charged beyond the manufacturer’s maximum voltage; confirms protective cut-off activates.
Forced discharge: Battery is discharged below minimum voltage; confirms over-discharge protection.
External short circuit: Short applied across battery terminals; verifies protective response.
Overcurrent protection: Confirms that protection triggers under excessive charge or discharge current.

Mechanical Tests

Vibration: Frequency sweep and sinusoidal vibration to simulate road exposure.
Mechanical shock: Half-sine shock pulses applied in all axes.
Drop test (removable batteries): Drop from defined height onto a hard surface.

Environmental and Thermal Tests

Thermal shock and cycling: Rapid transitions between temperature extremes; evaluates seal and material integrity.
High temperature endurance: Battery held at elevated temperature to verify no failure.
Humidity exposure: Verifies that moisture does not compromise safety.
Water ingress (IP rating): Protection against water confirmed through standardised IP test procedures.

System-Level Tests

Thermal propagation / thermal runaway: Verifies that a thermal event in one cell does not propagate uncontrolled to the whole pack (added emphasis in A1:2021).
BMS safety function verification: Confirms Battery Management System protective logic for charge, discharge, and temperature limits.

Certification and Regional Recognition

EN 50604-1 is a European standard and a harmonised standard referenced under EU safety and market access frameworks for light electric vehicles. Key requirements:

European Union: Compliance with EN 50604-1 is needed for batteries in EPACs (electric bicycles) under EN 15194:2017+A1:2023. It is also relevant for type approval of L-category vehicles under EU Regulation 168/2013.
United Kingdom: Adopted as BS EN 50604-1 by BSI; recognised in UK market access requirements for e-bikes and light electric vehicles.
As of 2026, E6 50604-1 is effectively mandatory for e-bike battery packs sold in the EU and UK as part of compliance with EN 15194.

Related Standards

IEC 62133-2 – Cell-level safety standard for portable sealed secondary lithium cells. Previously referenced in EN 50604-1 for EPAC batteries; replaced by EN 50604-1 itself as the applicable standard following A1:2021.
EN 15194:2017+A1:2023 – European standard for electrically power-assisted cycles (EPACs); references EN 50604-1 for traction battery safety compliance.
ECE R136 – UNECE type-approval regulation for L-category electric vehicles; complementary vehicle-level regulation covering the same LEV category as EN 50604-1.
UN 38.3 â Transport testing for lithium batteries; required before shipping battery packs for LEV applications.
EU Battery Regulation (2023/1542) – New EU regulation that defines LMT (light means of transport) batteries as a distinct category and introduces performance and sustainability requirements for e-bike and LEV batteries.
IEC 62619 – Safety requirements for secondary lithium cells and batteries for industrial applications.

Disclaimer: This page is not a definitive guide, just an indication and it is important that you always go back to the source for legislation.