SIST EN 62877-1:2016

Electrolyte and water for vented Lead Acid accumulators - Part 1: Requirements for electrolyte

IEC 62877-1:2016 applies to electrolyte and their components used for filling vented lead-acid batteries, for example dry charged cells or batteries, and for electrolyte replacement or electrolyte density adjustment of batteries in operation. This international standard defines the composition, purity and properties of electrolyte to be applied where specific instructions from the battery manufacturer are not available.

Elektrolyte und Wasser für geschlossene Blei-Säure-Batterien - Teil 1: Anforderungen an Elektrolyte

Electrolyte et eau pour accumulateurs plomb acide ouverts - Partie 1: Exigences pour l'électrolyte

L'IEC 62877-1:2016 s'applique à l'électrolyte et à ses composants utilisés pour le remplissage des batteries plomb-acide ouvertes, par exemple les éléments chargés secs ou les batteries chargées sèches et pour le remplacement de l'électrolyte ou l'ajustement de la densité de l'électrolyte des batteries en fonctionnement. La présente norme internationale définit la composition, la pureté et les propriétés de l'électrolyte qui doivent être appliquées en l'absence d'instructions spécifiques du fabricant de batteries.

Elektrolit in voda za oddušne svinčeve akumulatorje - 1. del: Zahteve za elektrolit

Ta del standarda IEC 62877 se uporablja za elektrolite in njihove komponente, ki se uporabljajo za polnjenje oddušnih svinčevih baterij, npr. suho polnjene celice ali baterije, in za zamenjavo elektrolita ali prilagoditev gostote elektrolita v delujočih baterijah. Ta mednarodni standard opredeljuje sestavo, čistost in lastnosti elektrolita, ki se uporablja, če ni na voljo podrobnejših informacij proizvajalca baterije.

General Information

• Status: Published
• Publication Date: 13-Jun-2016
• ICS: 29.220.20 - Acid secondary cells and batteries
• Technical Committee: ISCB - Secondary cells and batteries
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 07-Jun-2016
• Due Date: 12-Aug-2016
• Completion Date: 14-Jun-2016
• Ref Project: EN 62877-1:2016 - Electrolyte and water for vented lead acid accumulators - Part 1: Requirements for electrolyte

Relations

• Corrected By: SIST EN 62877-1:2016/AC:2020 - Electrolyte and water for vented lead acid accumulators - Part 1: Requirements for electrolyte
• Effective Date: 30-May-2017
• Revised: SIST EN IEC 62877-1:2024 - Electrolyte and water for vented lead acid accumulators - Part 1: requirements for electrolyte
• Effective Date: 01-Dec-2023

Overview

EN 62877-1:2016 (CLC / IEC 62877-1:2016) specifies requirements for electrolyte used in vented lead‑acid accumulators. It applies to diluted sulfuric acid used for first filling of dry‑charged cells and batteries, for electrolyte replacement, and for density adjustment during battery operation where the battery manufacturer’s instructions are not available. The standard defines composition, purity, physical properties and preparation/handling guidance to ensure safe, reliable battery performance.

Key topics and technical requirements

• Scope and definitions: clear terms for filling electrolyte, operating electrolyte, specified density, electrolyte level, and electrolyte additives.
• Preparation: electrolyte is prepared by adding concentrated sulfuric acid to purified water (always pour acid into water). Mixing safety and handling advice is emphasised.
• Physical properties: procedures and formulae to correct measured electrolyte density to the reference temperature (25 °C). The standard includes a conversion equation plus correction factors (see Table 1).
• Density relationships: tables correlating electrolyte density and percent sulfuric acid at 25 °C and guidance on density versus state of charge (Table 2).
• Purity and impurities: maximum permissible impurities for filling electrolyte and operating electrolyte are defined (Tables 3 and 4). These impurity limits help prevent battery damage and performance loss.
• Measurement accuracy: electrolyte density measurement guidance (densimeters, hydrometers or electronic devices) with instrument accuracy better than ±0.001 kg/l.
• Storage and remediation: requirements for storing electrolyte safely and steps to remedy damage caused by electrolyte contamination or misuse.
• Additives: electrolyte additives (e.g., alkaline metal sulfates) must be specified or approved by the battery manufacturer-unspecified additives are discouraged.

Practical applications and users

This standard is essential for:

• Battery manufacturers specifying electrolyte composition and filling procedures.
• Maintenance technicians and service providers performing first fills, topping up or electrolyte replacement.
• Chemical suppliers producing and certifying sulfuric acid and purified water for battery use.
• Test laboratories and OEMs verifying electrolyte density, purity and compliance.
• Safety and compliance teams ensuring handling, storage and documentation meet industry norms.

Using EN 62877-1 helps extend battery life, avoid contamination-related failures, and ensure consistent performance of vented lead‑acid batteries.

Related standards

• EN / IEC 62877-2 - Requirements for water used in preparation and topping up (normative reference).
• IEC 62485-3 is noted in the bibliography (harmonized as EN 62485-3).

Keywords: electrolyte, vented lead‑acid accumulators, sulfuric acid, electrolyte density, filling electrolyte, operating electrolyte, battery maintenance, electrolyte impurities, purified water, EN 62877-1.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2016
(OHNWUROLWLQYRGD]DRGGXãQHVYLQþHYHDNXPXODWRUMHGHO=DKWHYH]DHOHNWUROLW
Electrolyte and water for vented Lead Acid accumulators - Part 1: Requirements for
electrolyte
Electrolyte et eau pour accumulateurs plomb acide ouverts - Partie 1: Exigences pour
l'électrolyte
Ta slovenski standard je istoveten z: EN 62877-1:2016
ICS:
29.220.20 .LVOLQVNLVHNXQGDUQLþOHQLLQ Acid secondary cells and
EDWHULMH batteries
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 62877-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2016
ICS 29.220.20
English Version
Electrolyte and water for vented lead acid accumulators -
Part 1: Requirements for electrolyte
(IEC 62877-1:2016)
Electrolyte et eau pour accumulateurs plomb-acide ouverts - Elektrolyte und Wasser für geschlossene Blei-Säure-Batterien -
Partie 1: Exigences pour l'électrolyte Teil 1: Anforderungen an Elektrolyte
(IEC 62877-1:2016) (IEC 62877-1:2016)
This European Standard was approved by CENELEC on 2016-03-02. 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, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 62877-1:2016 E
European foreword
The text of document 21/874/FDIS, future edition 1 of IEC 62877-1, prepared by IEC/TC 21
"Secondary cells and batteries" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 62877-1:2016.
The following dates are fixed:
(dop) 2016-12-02
• latest date by which the document has to be implemented at
national level by publication of an identical national
standard or by endorsement
(dow) 2019-03-02
• latest date by which the national standards conflicting with
the document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 62877-1:2016 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated :
IEC 62485-3 NOTE Harmonized as EN 62485-3.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.

Publication Year Title EN/HD Year
-
IEC 62877-2 -  Electrolyte and water for vented lead EN 62877-2
acid accumulators -
Part 2: Requirements for water

IEC 62877-1 ®
Edition 1.0 2016-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrolyte and water for vented lead acid accumulators –

Part 1: Requirements for electrolyte

Électrolyte et eau pour accumulateurs plomb-acide ouverts –

Partie 1: Exigences pour l'électrolyte

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.220.20 ISBN 978-2-8322-3139-5

– 2 – IEC 62877-1:2016 © IEC 2016
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references. 5
3 Terms and definitions . 5
4 Preparation of electrolyte for lead-acid accumulators . 7
5 Physical properties of diluted sulfuric acid as electrolyte . 7
5.1 Dependence of acid density on temperature . 7
5.2 Relationship of electrolyte density on the content of sulfuric acid at 25 °C . 8
5.3 Electrolyte density compared to the state of discharge . 8
6 Requirements of sulfuric acid used as electrolyte . 8
6.1 Impurities of sulfuric acid of higher concentration degrees . 8
6.2 Impurities of filling acid . 8
6.3 Impurities of operating electrolyte . 9
7 Storage of electrolyte . 10
8 Remedy in the event of damage due to electrolyte . 10
Bibliography . 12

Table 1 – Correction of density from measuring temperature to reference/specified
temperature . 7
Table 2 – Acid density versus percentage of sulphuric acid at 25 °C . 8
Table 3 – Maximum allowed impurities of diluted sulfuric acid as filling electrolyte
for lead-acid batteries in the density range ≤ 1,30 kg/l . 9
Table 4 – Maximum allowed impurity of diluted acid as operating electrolyte
for lead-acid batteries in the density range ≤ 1,30 kg/l . 10

IEC 62877-1:2016 © IEC 2016 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROLYTE AND WATER FOR VENTED
LEAD ACID ACCUMULATORS –
Part 1: Requirements for electrolyte

FOREWORD
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62877-1 has been prepared by IEC technical committee 21:
Secondary cells and batteries.
The text of this standard is based on the following documents:
FDIS Report on voting
21/874/FDIS 21/881/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – IEC 62877-1:2016 © IEC 2016
A list of all parts of the IEC 62877 series can be found, under the general title Electrolyte and
water for vented lead acid accumulators, on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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