National foreword

This British Standard is the UK implementation of EN 50342‑6:2025. It supersedes BS EN 50342‑6:2015+A1:2018, which will be withdrawn on 31 August 2028.

The UK participation in its preparation was entrusted to Technical Committee PEL/21, Secondary cells and batteries.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2025.

This European Standard was approved by CENELEC on 23 June 2025. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.

European foreword

This document (EN 50342‑6:2025) has been prepared by CLC/TC 21X “Secondary cells and batteries”.

The following dates are fixed:

This document supersedes EN 50342‑6:2015 and all of its amendments and corrigenda (if any).

TC21X working group 3 has been agreed to implement an improved version of Micro-hybrid test (MHT). This test replaces the version of EN 50342‑6:2015.1

EN 50342‑6:2025 includes the following significant technical changes with respect to EN 50342‑6:2015:

change of test temperature from 25 °C to 40 °C for entire test procedure including initials, cycling and check-up;
change from 100 cycles to 200 cycles each test block;
change of rest time between blocks from 12 h to 3 h;
change of total number of cycles from 8000 to 16000;
a new performance level “D” for dynamic charge acceptance (DCA) with two steps has been introduced and some minor errors have been corrected.

EN 50342, Lead-acid starter batteries, is currently composed of the following parts:

Part 1: General requirements and methods of test;
Part 2: Dimensions of batteries and marking of terminals;
Part 3: Terminal system for batteries with 36 V nominal voltage;
Part 4: Dimensions of batteries for heavy vehicles;
Part 5: Properties of battery housings and handles;
Part 6: Batteries for Micro-Cycle Applications [the present document];
Part 7: General requirements and methods of tests for motorcycle batteries.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Any feedback and questions on this document should be directed to the users’ national committee. A complete listing of these bodies can be found on the CENELEC website.

1 Scope

This document is applicable to lead-acid batteries with a nominal voltage of 12 V, used primarily as power source for the starting of internal combustion engines (ICE), lighting and also for auxiliary equipment of ICE vehicles. These batteries are commonly called “starter batteries”. Batteries with a nominal voltage of 6 V are also included in the scope of this document. All referenced voltages need to be divided by two for 6 V batteries. The batteries under the scope of this document are used for micro-cycle applications in vehicles which can also be called Start-Stop (or Stop-Start, idling-stop system, micro-hybrid or idle-stop-and-go) applications. In cars with this special capability, the internal combustion engine is switched off during a complete vehicle stop, during idling with low speed or during idling without the need of supporting the vehicle movement by the internal combustion engine. During the phases in which the engine is switched off, most of the electric and electronic components of the car need to be supplied by the battery without support of the alternator. In addition, in most cases an additional regenerative braking (recuperation or regeneration of braking energy) function is installed. The batteries under these applications are stressed in a completely different way compared to classical starter batteries. Aside of these additional properties, those batteries need to crank the ICE and support the lighting and also auxiliary functions in a standard operating mode with support of the alternator when the internal combustion engine is switched on. All batteries under this scope need to fulfil basic functions, which are tested under application of EN 50342‑1:2015.

This document is applicable to batteries for the following purposes:

Lead-acid batteries of the dimensions according to EN 50342‑2 for vehicles with the capability to automatically switch off the ICE during vehicle operation either in standstill or moving (“Start-Stop”);
Lead-acid batteries of the dimensions according to EN 50342‑2 for vehicles with Start-Stop applications with the capability to recover braking energy or energy from other sources.

This document is not applicable to batteries for purposes other than mentioned above, but it is applicable to EFB delivered in dry-charged conditions according to EN 50342‑1:2015, Clause 7.

NOTE The applicability of this document also for batteries according to EN 50342‑4 is under consideration.

2 Normative references

3 Terms and definitions

4 General

4.1 Designation of starter batteries

4.2 Condition on delivery

5 General requirements — Identification and labelling

6 General test conditions

6.1 Characteristics and abbreviations

6.2 Syntax of test descriptions

6.3 Requirements for measuring equipment capability

6.4 Sampling of batteries

7 Test sequence

8 Inspections and test procedures

8.1 Charging of batteries

8.2 Micro-hybrid test (MHT)

8.3 Dynamic charge acceptance test (DCA)

8.4 Endurance in cycle test with 17,5 % depth of discharge (DoD)

8.5 Endurance in cycle test with 50 % depth of discharge (DoD) at 40 °C and preceded deep discharge

9 Requirements and battery performance levels

9.1 General

9.2 Tests to be passed (no performance differentiation)

9.3 Tests determining the DCA performance level

9.4 Tests determining the micro-cycle performance level

Bibliography

BS EN 50342-6:2025

Lead-acid starter batteries - Batteries for micro-cycle applications

Current

Published:

31 Aug 2025