IEEE 1189-2007 pdf download IEEE Guide for Selection of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications
1.1 Scope
This guide describes methods for selecting the appropriate type of valve-regulated, immobilized.electrolyte, recombinant lead-acid battery for any of a variety of stationary float applications. Installation.maintenance, sizing, and consideration of battery types, other than valve-regulated lead-acid batteries, arebeyond the scope of this guide. Design of the dc system and sizing of the dc battery charger(s) are alsobeyond the scope of this guide.
1.2 Purpose
The purpose of this document is to ensure that the reader is aware of all significant issues that should beconsidered when selecting VRLA batteries, so that the user might make an informed decision.
2.Normative references
The following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenceddocument(including any amendments or corrigenda) applies.
IEEE Std 485TM，EEE Recommended Practice for Sizing Lead-Acid Batteries forStationaryApplications.
IEEE Std 1187TM,IEEE Recommended Practice for Installation Design and Installation of Valve-RegulatedLead-Acid Storage Batteries for Stationary Applications.
IEEE Std 1188TM,IEEE Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications.
3. Definitions
For the purposes of this guide, the following terms and definitions apply, The Authoritative Dictionary ofEEE Standards Terms (B16]’ should be referenced for termms not defined in this clause.
3.1 absorbed electrolyte cel: A cell in which the liquid electrolyte is immobilized in fiberglass orpolymeric fiber separators.
3.2 gelled electrolyte cell: A cell in which the electrolyte is immobilized by addition of a gelling agent
3.3 immobilized electrolyte: Electrolyte in a cell that is prevented from flowing by use of either gelled orabsorbed electrolyte technology.
3.4 oxygen recombination: The process by which oxygen is generated at the positive plates and ultimatelyrecombined with hydrogen ions at the negative plates and converted back to water.
3.5 oxygen recombination efficiency: The amount of oxygen ultimately converted to water at the negativeplates expressed as a percentage of the total amount of oxygen produced at the positive plates.
3.6 polarization: The shift in the potential of an electrode, or the voltage of a cell/battery, from the opencircuit valuc. brought about by the flow of current
4. Technology overview
4.1 Water loss
In a vented lead-acid cell, water is lost during overcharge by a process known as electrolysis. In thisprocess, oxygen is evolved at the positive plates and hydrogen is evolved at the negative plates. The oxygenand hydrogen gases are allowed to vent out of the cell into the atmnosphere, resulting in the loss of water.
In VRLA cells, the process of oxygen recombination limits water loss. However, other processes exist thatresult in water loss from VRLA cells. See 4.5 and 5.3.1
4.2 Oxygen recombination
In a perfect water-to-oxygen-to-water cycle, all the oxygen produced at the positive plates on float orovercharge would be transported to the negative plates and converted back to water, with no water beinglost from the cell. This is the basis for VRLA cell technology (see Annex A for more details).
4.3 Oxygen transport between positive and negative plates
The efficiency of the oxygen recombination cycle depends primarily on the ability to transport the oxygengenerated at the positive plates to the negative plates. In vented lead-acid cells, the transport process is
IEEE 1189-2007 pdf download
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