library of Technical papers
Battcon 2006 Harold A. Vanasse, Daniel M. Jones
Monobloc Batteries, High Temperatures & Catalysts (104 kb PDF)
12-Volt Monobloc VRLA batteries have become very popular in recent years, especially in outside plant applications. As is being discovered, the high temperatures of the outside plant environment are not conducive to the life of these batteries. This paper will explore the effects of high temperatures on Monobloc VRLA batteries, in particular their life. The reasons why high temperature can cause these batteries to deliver less life than their theoretical life expectations will also be explored. The use of catalysts in Monobloc VRLA batteries will also be presented as a potential way to mitigate the effects of high temperature on life. A background review of the fundamentals of how catalysts work in VRLA batteries will also be included as a primer. Test results to date will be presented.
INFOBATT 2004 Harold A. Vanasse, Robert Anderson
A Case Study: Four Years of Performance Data at a Canadian Rehydration & Catalyst Addition Test Site (9kb PDF)
Four years ago a string of high quality 2-Volt VRLA cells underwent the rehydration and catalyst addition process. The cells were manufactured in 1993 and were in very bad shape prior to the start of the process: signs of positive plate growth, low capacity and less than adequate delivery of run time. After the rehydration and catalyst addition process every cell in this 48-volt string made a dramatic recovery, including delivery of the required load during the August 2003 blackout. It has been 4 years since water and catalysts were added to these cells and the latest performance data has just been collected. The results are very good and will be presented in case study fashion along with an explanation of what is occurring inside the cells to account for the turnaround in performance.
INFOBATT 2003 Harold A. Vanasse, Robert Anderson
Advances in the Design and Application of Catalysts for VRLA Batteries (9kb PDF)
This presentation will expand upon the information presented at last year's INFOBATT conference by presenting further advances in the design of the catalyst device itself and refinements in the rehydration & catalyst addition process. As with last year's presentation, this presentation will be a mix of theoretical, scientific and practical information.
BATTCON 2003 Harold A. Vanasse, Daniel M. Jones
Catalyst 201: Catalysts and Poisons from the Battery (185kb PDF)
In our previous paper we described the benefits of using catalysts in VRLA cells by offering a simplified explanation of what occurs inside a VRLA cell once a catalyst is introduced into it. This paper will be the second in a series of papers designed to build the knowledge base of end users on catalyst science and will introduce the topic of catalyst poisons and the solutions needed to survive them.
This paper will offer a simplified explanation of what is occurring inside the cell to produce hydrogen sulfide and what steps are necessary to filter out the poison before it reaches the catalysts. Theoretical and empirical data, including field data, will be used to highlight the main points of the paper.
Battcon 2002 Harold A. Vanasse, Dan Jones
Catalyst 101: The Basics Of Using Catalysts In VRLA Cells (735kb PDF)
Over the past four years of producing and selling catalysts we have been asked many questions about their use in VRLA cells. A lot of confusion exists on the part of people who have problems with their batteries. They ask us many questions about the catalyst and whether it can help them with problems like capacity loss, cell dryout, and thermal runaway, to name a few. The purpose of this paper is to address questions like this and demystify the use of catalysts in VRLA cells by offering a simplified explanation of what is occurring inside the cell once a catalyst is introduced into it.
INTELEC 2001 Harold A. Vanasse, Frank J. Vaccaro, and Volen R. Nikolov
Hydrogen Sulfide in VRLA Cells (486kb PDF)
This paper outlines the investigation into hydrogen sulfide (H2S) generation in VRLA cells. Mostly unexpected in the battery industry, the authors contend that H2S is produced in high concentrations by a reaction between the negative plate and sulfuric acid. They also show that the lead oxides of the positive plate absorb the H2S in large quantities and that the resulting concentration of H2S emitted from a cell is less than 1 ppm under normal circumstances.
INTELEC '00 William E.M. Jones
Quantifying Secondary Reactions in VRLA Batteries (76kb PDF)
This paper presents a new spin on an old test to measure the purity of active material. A large variety of battery manufacturer’s negative plates were charged, removed from their cells and allowed to self discharge under acid. The hydrogen gas emitted was collected and measured. The gas generated was due to pure chemical self-discharge of the negative active material and is a measure of the purity of the negative active material. The paper describes the test and the equipment used in detail. The results of the testing find great variability among manufacturers. A small number of the samples tested have self-discharge rates that indicate that negative plates are pure enough to keep a VRLA cell in balance, without a catalyst. Many other manufacturer’s negative plates are clearly gassing too much to survive 20 years. This is a direct result of impurities in the materials used to manufacture the negative plates. If this is not possible or economical, then the use of a catalyst is still a viable option.
INTELEC '98 D. Berndt, W.E.M. Jones
Balanced Float Charging of VRLA Batteries by Means of Catalysts (857kb PDF)
This is a highly technical paper that explains the cell imbalance problem and the catalyst solution from an electrochemical perspective. Exquisite Tafel diagrams along with other empirical data is presented by this renowned expert.
INTELEC '98 W.E.M. Jones, H.A. Vanasse, C.E. Sabotta, J.E. Clapper, E.F. Price
Can VRLA Batteries Last 20 Years? (393kb PDF)
This paper presents conclusive data from a key long-term test of VRLA cells half of which were equipped with internal catalysts. The data clearly shows that when a catalyst is installed into a cell negative plate self discharge is prevented, along with a whole list of secondary benefits. A detailed description of the test setup and the equipment used is presented. This paper also gives a very detailed description of how the catalyst works to correct the imbalance in a cell. Frequently asked questions are presented and answered for Philadelphia Scientific’s first generation catalyst device.
TELESCON '97 W.E.M. Jones, D.O. Feder
Correcting Inherent Imbalances and Consequent Failure of VRLA Cells by the Use of Catalysts (88kb PDF)
This paper presents the cell balance theory for why VRLA cells on float self-discharge over time. The theory states that the hydrogen equivalent of the positive plate grid corrosion must not be less than the hydrogen emitted by the negative plate for the cell to stay in balance. If more hydrogen if emitted from the negative plate then the cell will be out of electrochemical balance. An out of balance cell will have negative plates that self-discharge under normal float service. Test data from two years of testing is used to support the theory, which is explained with very clear, easy to understand diagrams. The use of a catalyst as a solution to the problem is expanded upon, again using very clear diagrams to illustrate the main points. The paradox of the central problem is presented: to make a balanced cell, the positive grid must corrode at a faster rate, which will mean that the 20 year design life will not be attained. A 20 year cell must have low corrosion positive plates to last that long, but then the cell will become unbalanced and will suffer negative plate self discharge.
INTELEC '96 D.O. Feder, W.E.M. Jones
Gas Evolution, Dryout, and Lifetime of VRLA Cells - An Attempt to Clarify Fifteen Years of Confusion and Misunderstanding (436kb PDF)
This paper outlines the early attempts to classify and quantify VRLA cell failure. A standardized theoretical measure, time to 10% water loss of a cell, is established to aid in determining cell failure. The authors used the new measure to determine time to cell failure based on a published cell data, field and lab studies of positive grid corrosion, cell weight loss and actual quantities of gas collected from cells on test. The battery lives predicted from the data ranged from 6 years to 1,300 years. This clearly highlighted the disparity that existed in the data sets and in the understanding of the problem in the industry.
This paper is a continuation of the 1995 paper that the authors wrote. The VRLA cells that were discussed in the 1995 paper have been on test for one more year and the data presented continues to the support the contentions presented in the earlier paper; cell gassing rates and hence cell water loss are too high to support 20 years of life. This is the first published reporting of using an internal catalyst to counter the effects of water loss in VRLA cells. The additional benefits of using a catalyst are also presented. They are float current reduction, increase in negative plate polarization, and decrease in positive plate polarization. This paper is also important in that it is the first to publish that the central problem with VRLA cells is negative plate depolarization and that this occurs even while the cells are on float charge. An internal catalyst is proposed as a possible solution to the problem.
INTELEC 1996 W.E.M. Jones, D.O. Feder
Behavior of VRLA Cells on Long Term Float: Part 2 (2788kb PDF)
This paper is also a continuation of the paper that the authors co-wrote in 1995. It presents a much more detailed description of the negative plate self discharge problem. Numerous graphs are presented that display plate polarizations and cell gas emissions to support their claims. This paper presents solid evidence in an easy to understand way on the basic problem of negative plate self-discharge and the effect it has on a cell. The relationship between cell water loss and negative plate self-discharge is established and clear evidence is presented to show that most VRLA cells will not meet their 20 year design life, especially if used in high temperature applications. The catalyst, as a solution, is presented along with test data to support the claims. This is a key paper to read to gain a full understanding of the problem and the solution.
INTELEC '95 W.E.M. Jones, D.O. Feder
Float Behavior of VRLA Cells: Theory vs. Reality (433kb PDF)
This paper is a very early study of water loss by VRLA cells. Gas that is exhausted form VRLA cell is collected and provides the basis for the water loss calculation. The gas collection technique and water loss derivation are presented. This paper is unique in that it specifies a water loss target (expressed as gas exhausted) that VRLA cells must meet in order to last for 20 years. Cell exhausting more than the gas-exhausted target will not achieve the 20-year design life. Data from VRLA cells on float is presented and shows that there is variability in gassing rates between manufacturers. What was more surprising is the variability that exists between cells from the same manufacturer. This paper also discusses the effects of cell dry out on the negative and positive plates, stressing the point that dry out of the positive plate leads to thermal runaway.
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