IEEE STD. 450™ 2010
IEEE RECOMMENDED PRACTICE FOR MAINTENANCE, TESTING
AND REPLACEMENT OF VENTED LEAD-ACID BATTERIES
FOR STATIONARY APPLICATIONS
M. S. (Steve) Clark
Senior Engineer
Bechtel Power Corp.
Knoxville, TN
INTRODUCTION
As our understanding of lead-acid batteries grows, the IEEE Stationary Battery Committee has continued the evolution of
IEEE Std. 450™ to meet the needs of users. The purpose of this paper is to provide a synopsis of the changes to IEEE
Std. 450 between the 2002 and 2010 versions. The focus is on how the changes impact battery maintenance practices. I had
the privilege of serving as the working group chair for this revision.
THE CHANGE PROCESS
The IEEE requires that all standards be either reaffirmed or revised every five years. The previous publication of IEEE
Std. 450 occurred in 2002. This meant action on the document was required in 2007. In 2006, the IEEE Stationary Battery
committee held an informal working group meeting to review the document and determine if it should be reaffirmed or
revised. The consensus of the working group was that there were sufficient changes to justify revising the document. The
working group then itemized the recommendations for changes and voted to identify changes to be addressed by the next
revision. At this point a Project Authorization Request (PAR) was submitted to the IEEE Standards Board to revise IEEE
Std. 450. After approval of the PAR, a formal working group was established for the purpose of revising the document.
IEEE Std. 450 2010 CHANGE SYNOPSIS
The following synopsis identifies the significant changes to the document and provides a brief discussion of why each change
was made.
1.
General: Added or verified the recommended practices encompassed the majority of the vented lead-acid battery types
including lead-calcium, lead-antimony, low antimony (aka lead-selenium) and pure lead.
In looking at the history of IEEE 450, the initial recommendations were based on lead-antimony battery technology. This
is because a long history of manufacturer and user data existed for lead-antimony maintenance. Since then, lead-calcium
batteries have become the dominant vented lead-acid battery type used in the U.S. As a result, over the years, 450 was
revised to reflect lead-calcium recommended maintenance practices. However, the intent of 450 is to provide
recommended practices for all vented lead-acid battery types. While the changes are often subtle, a significant amount of
research went into either confirming or making adjustments to ensure the document addresses the majority of the vented
lead-acid battery technologies used world wide.
7-1
2.
Clause 5.2.4: Added guidance on when specific gravity readings should be taken and a recommendation to contact the
manufacturer for guidance for special inspections
As our understanding of vented lead-acid batteries has improved, specific gravity (SG) measurements have become less
important. Some manufacturers have gone so far as to eliminate the sample tubes. The 2010 revision reflects a consensus
among manufacturers who still recommend measurement of SG and users desire to limit maintenance activities to those
that provide state-of-health information. Agreement was reached that as a minimum a complete set of SG readings
should be taken upon initial installation and after two years of service.
Special inspections following abnormal operating events have been a matter of discussion for the last two revisions of
the document. For this revision, the working group agreed to remove any specific guidance and to direct the user to
contact the manufacturer.
3.
Clause 5.2.5: Added clause to address battery monitoring systems
IEEE 1491 - Battery Monitoring was published in 2005. As monitoring systems become more common, it is appropriate
to include them in the routine maintenance instructions for stationary batteries. For this revision the working group added
information on how to use monitoring systems as part of the battery maintenance program. A statement was also added
that monitoring systems cannot replace periodic visual inspections.
4.
Clause 5.3.2: Removed values for equalizing voltage and referred to manufacturer’s instructions.
Over the last several years, the manufacturers have been changing the minimum individual cell voltage (ICV) values for
determining when an equalize charge should be performed. Since the manufacturers were unable to come to consensus
on a voltage range for recommending when an equalize charge should be performed, the working group elected to
remove the numeric values and refer users to the manufacturer’s instructions.
5.
Clause 5.3.2: Removed SG measurements for determining if an equalizing charge is need.
SG changes are accompanied by changes in ICV. Since ICV changes quickly and before SG (which changes slowly), the
use SG in determining if an equalize charge is necessary was removed.
6.
Clause 5.3.2: Added guidance for undercharge conditions.
Prolonged undercharge of a battery is a serious condition that is most often rectified by applying an equalizing charge to
the battery or individual cell(s). 5.3.2b) was added to address this condition using an equalizing charge as the corrective
action.
7.
Clause 5.4: State of charge rewritten and expanded to update guidance on using specific gravity or float current as a state
of charge indicator. Added Indications and interpretations section to the discussion.
Determining state-of-charge is a significant issue for the nuclear power industry and is becoming an issue for
transmission and distribution companies as well. Because of this, the section was extensively revised to provide updated
information on this critical data point.
8.
Clause 6.1: Added to provide general information about battery testing.
This was an editorial change to bring the document into compliance with the IEEE standards style guide. It is mentioned
here because it resulted in renumbering of the subsequent clauses.
7-2
9.
Clause 6.2: Acceptance test – added prerequisites for site acceptance testing. Added guidance for acceptable initial cell
capacity.
Prerequisites were omitted in the previous versions. This oversight was corrected.
The consensus of the working group is that every cell of a new battery should have at least 90% capacity on delivery.
This addition was made based on questions from users concerning cell versus battery capacity for a new battery.
10. Clause 6.2: Updated guidance on use of rate-adjusted test methodology for Acceptance Testing.
The discussion on the use of Acceptance Test data for trending battery capacity over time, was revised to ensure that the
data taken is consistent. The use of rate adjusted testing was revised to specify that the manufacturer’s published data not
adjusted for end of life should be used for acceptance tests.
11. Clause 7.1: Added to provide general information about battery testing.
This was an editorial change to bring the document into compliance with the IEEE standards style guide. It is mentioned
here because it resulted in renumbering of the subsequent clauses.
12. Clause 7.1: Added use of thermography as a diagnostic tool during all battery discharge tests.
This is an industry good practice that was included to support inexperienced users.
13. Clause 7.1.1: Added for testing of parallel strings
Parallel string testing is something that was not included in previous versions of the document. However, as lead-acid
batteries are deployed in new applications requiring higher currents and longer service times, the use of parallel strings is
expanding beyond its previous user base. For this reason the working group considered that this subject needed to be
included.
14. Clause 7.2c): Performance test initial conditions revised to reflect use of float current instead of specific gravity for other
than lead-antimony battery types.
This change reflects the use of float current as a state-of-charge indicator for battery types other than lead-antimony.
15. Clause 7.4.3.1: Added to provide general information and provide information on testing using either end-of-life or fullpublished rate.
One of the weaknesses of the previous revision identified was in the area of rate-adjusted capacity testing. Significant
work was done to address the identified issues. The addition of a General section was required to match the IEEE
standards style guide. The inclusion of information on both end-of-life or full-published rate testing was done to provide
information that was missing from the previous revision.
16. Clause 7.4.3.2: Revised the rate adjusted test methodology temperature adjustment to not make adjustment if the battery
temperature is the range of 15 to 35 ºC.
Adjusting the rate to reflect the actual battery temperature is not required if the battery is in the normally expected
operating range of 15 to 35 ºC. This was done simplify the test and reduce the chance of a human performance error if
the rate is incorrectly adjusted.
17. Clause 7.4.3.3: Added section on rate-adjusted testing at the full manufacturer’s rating.
While rate-adjusted testing is often performed using the end-of-life methodology, there are times, such as performing an
Acceptance Test, that it is appropriate to use the full-published rate method. This section was added to provide the
information on when and how to use this method.
7-3
18. Clause 7.5: Initial conditions, added a) to address modified performance tests
The initial conditions section was unintentionally omitted from the previous revision of the document.
19. Clause 9: Added statement to retain records for the life of the battery.
This statement was added to meet manufacturer’s requirements for records retention.
20. Clause 10: Added section on data trending
Two types of data are collected during battery inspection and test activities, state-of-health and battery life expectancy.
State-of-health data provides a snapshot in time of the battery condition. Battery life expectancy data enables the users to
predict when the battery will reach end of life. Trending state-of-health data is not seen as providing insight into long
term battery performance and is not recommended. Trending battery life expectancy is recommended since it enables the
user to plan replacement activities.
21. Clause 12: Added section on spill containment
This section was added to refer the user to IEEE 1578 - Battery Spill Containment which was published in 2007 and not
to provide detailed guidance on the subject. It reflects the fact that many authorities having jurisdiction (AHJ) are
requiring spill containments to be installed for vented battery installations.
22. Annex A.3: Added information on SG for lead-antimony batteries and averaging of SG measurements from different
points in the cell.
This section was reworked to make it specific to lead-antimony battery technology and to provide additional information
on the changes in SG during battery discharge and recharge.
23. Annex C.3.1: Added section on cells with low ICV
Low voltage cells are a common concern for users of lead-calcium batteries. The previous revision did not address this
common issue.
CONCLUSIONS
IEEE Std. 450 2010 is not a radical reworking of the document. Rather it is an evolutionary document that reflects updated
information on battery maintenance practices and contains information on advances in stationary battery installation design.
RECOMMENDATIONS
Users should stay current with IEEE documents that impact their normal maintenance practices and update their practices as
appropriate for their installations. Manufacturers should review the latest consensus documents and update their publications
as appropriate.
REFERENCES
IEEE Std. 450 2010 (Revision of IEEE Std. 450-2002) IEEE Recommended Practice for Maintenance, Testing, and
Replacement of Vented Lead-Acid Batteries for Stationary Applications
7-4
ACKNOWLEDGEMENTS
The following individuals contributed to the success of IEEE Std. 450 2010:
Julie Alessi
Phyllis Archer
Curtis Ashton
Tim Bolgeo
Robert Beavers
William Cantor
Thomas Carpenter
Leonard Casella
Terry Chapman
Bart Cotton
Thomas Croda
Peter Demar
Robert Fletcher
Kyle Floyd
John Gagge, Jr.
Al Jensen
Wayne Johnson
Michael Jump
Soo Kim
Jeffrey LaMarca
Daniel Lambert
José Marrero,
Stephen McCluer
Matthew McConnell
Russell Miller
Tania Martinez Navedo
Michael Nispel
Howard Nudi
Rudy Ortega
John Polenz
Edward Rafter
Jan Reber
Christopher Searles
Joseph Stevens
H. F. Taylor
Richard Tressler
Kurt Uhlir
Lesley Varga
Allan Williamson
TRADEMARKS
IEEE Std 450™ is a registered trademark of the Institute of Electrical and Electronics Engineers Inc.
7-5