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AlphaCell VRLA Battery SystemPeriodic Maintenance and Troubleshooting Guide

Table of Contents

Battery System General Information & DescriptionSeries string 1Parallel string 1

VRLA Battery Safety ConcernsElectrical Hazards 2Disposal 2Chemical Hazards 2Fire, Explosion and Heat Hazards 2Handling Hazards 3

Preparation for Periodic MaintenanceRequired Maintenance Tools and Equipment 3

Periodic Maintenance Tasks and ScheduleQuarterly Maintenance 4Semi-Annual Maintenance 4Annual Maintenance 4Bi-Annual Maintenance 4

Data Analysis and Corrective ActionsEnvironment Ambient and Battery Temperature 5Battery Visual Inspection 5Battery System Float Charging Voltage 6Battery System Float Charging Current 7Individual Battery Float Charging Voltage 7High Rate Momentary Load Test 8Battery Impedance Testing 8Interunit Connection Resistance 8Performance & Capacity Testing 9Summary of Periodic Maintenance 9

TablesTable 1 - Battery System Symptoms and Solutions 10Table 2 - Battery Parameters by Model Number 15

FiguresFigure 1 - Series String of VRLA Batteries 1Figure 2 - Parallel Strings of VRLA Batteries 2Figure 3 - Float Current vs. Float Voltage 8Figure 4 - VRLA Battery Impedance vs. Capacity and Age 9

AppendicesAppendix 1 - VRLA Battery Periodic Maintenance Data Recording Form 16

JUNCTIONBOX

STRING B

STRING A

CIRCUIT BREAKER B

CIRCUIT BREAKER A

NOTE: L1 + L2 = L3 + L4

L1 L2

L3 L4

CIRCUIT BREAKER

AlphaCell VRLA Battery SystemPeriodic Maintenance and Troubleshooting Guide

General Information

This Pamphlet provides a guide for use during periodic maint-nance and troubleshooting of the AlphaCell VRLA batteries of 20through 200 ampere hours capacity.

Other instructional pamphlets which can be used in conjunctionwith this guide include:

- Integrity Testing- Impedance and Conductance Testing- Acceptance and Capacity Testing

General Description

In general the battery system is a group of 12 volt batteries connected in a series string to provide a total system of highervoltage. For example, as shown in Figure 1, four of the nominal12 volt batteries may be connected in series to provide a 24 cellsystem with a nominal voltage of 48 volts.

Figure 1Series Connected String of Batteries

Multiple strings of the series connected batteries may be con-nected in parallel to provide a total system with a capacity of thesum of the capacities of the individual strings. For example, asshown in Figure 2, two each 48 volt 90 ampere hour capacitystrings can be connected in parallel to provide a nominal 48 voltsat 180 ampere hours.

Figure 2Parallel Strings of Batteries

The AlphaCell VRLA battery is a lead acid battery whichfacilitates an oxygen recombination cycle. The net result isthat under normal conditions there is a minimal gas emis-sion and loss of water from the electrolyte. The electrolyteis immobilized in either a gel form or is absorbed within anabsorbent separator between the plates. Consequently, thebattery is maintenance free in terms of electrolyte mainte-nance—that is, there is no requirement nor capacity to addwater to the cells or to measure the electrolyte specificgravity.

VRLA Battery Safety ConcernsMaintenance and servicing of the AlphaCell VRLA batteryshould only be performed and supervised by personnelknowledgeable of lead acid batteries and required personalsafety and equipment safety precautions. Keep unautho-rized personnel away from the batteries and maintenanceactivities.

1

Electrical Hazards

Battery systems present a risk of electrical shock and highshort circuit currents. The following precautions should beobserved when maintaining VRLA batteries:

1. Remove all personal metal objects (watches, rings, etc)

2. Use insulated tools.

3. Wear full eye protection and rubber gloves.

4. Observe circuit polarities.

5. Do not make or break live circuits.

6. Prior to handling batteries on a metal rack, assure the battery is not inadvertently grounded by observing the ground fault detector indicator. In its absence, measure the voltage between the battery and the rack. It should be zero. if not, determine the cause and correct prior to proceeding.

7. Do not lay metal tools and hardware on top of the batteries.

8. As appropriate, use an insulating blanket to cover exposed portions of the battery system whenper forming extended maintenance that could result in personal or equipment contact with the energized conductors.

Certain types of rectifier circuits used in charging the VRLAbattery may not include a line isolating transformer. Inthese cases extreme caution should be exercised whenmaintaining and collecting data on the battery system.

The VRLA battery is sometimes enclosed in cabinets withvery limited access. Again, extreme caution should be exer-cised when maintaining and collecting data on the battery system.

Disposal

Lead acid batteries are to be recycled. Batteries containlead and dilute sulfuric acid. Dispose of accordance withFederal, State and local regulations. Do not dispose of in a landfill, lake or other unauthorized location.

Chemical Hazards

Any gelled or liquid emissions from a VRLA battery is elec-trolyte which contains dilute sulfuric acid which is harmfulto the skin and eye; is electrically conductive; and is corro-sive.

If electrolyte contacts the skin, wash immediately and thor-oughly with water. If electrolyte enters eyes, wash thor-oughly for 10 minutes with clean water or a special neu-tralizing eye wash solution and seek immediate medicalattention.

Neutralize any spilled electrolyte with the special solutionscontained in a “spill kit” or a solution of 1lb. bicarbonateof soda to 1 gallon of water.

Fire, Explosion and Heat Hazards

Lead acid batteries can contain an explosive mixture ofhydrogen gas which can vent under overcharging conditions.

Do not smoke or introduce sparks in the vicinity of the battery.

Prior to handling the batteries, touch a grounded metalobject, such as the rack, to dissipate any static charge thatmay have developed on your body.

Do not charge batteries in a sealed container. The individualbatteries should have 0.5 inches of space between the bat-teries to allow for convection cooling. If contained, assurethe container or cabinet and room have adequate ventilationto prevent an accumulation of potentially vented gas.

Caution

Do not attempt to remove the vents (valves) from theAlphaCell VRLA battery or add water. This presents a safety hazard and voids the warranty.

2

Handling Hazards

The individual batteries may weigh from 25 to 100 poundsdepending on part number. Exercise care when handlingand moving batteries. Assure the use of appropriate han-dling equipment.

Preparation for Periodic MaintenanceThere is little difference between the periodic maintenanceassociated with a VRLA battery and a vented (wet) cell bat-tery with the exception of that related to the liquid elec-trolyte. Naturally, it is not required to measure electrolytespecific gravity or add water to the VRLA cells.

For optimum reliability, it is recommended that the batterysystem be monitored quarterly. If the battery system incor-porates an automatic monitoring system to gather the elec-trical and environmental data, the quarterly checks arelimited to the evaluation of the recorded data and a visualcheck of the battery.

In general, the types of checks to be made during the peri-odic maintenance include:

1. System charging voltage.

2. Ambient temperature.

3. Battery pilot unit temperatures.

4. Interunit connection hardware resistanceor tightness.

5. Individual battery float voltage.

6. Momentary high rate load test.

7. Battery system capacity test.

A test of the individual unit resistance, impedance or con-ductance, while optional, is also recommended on a period-ic basis. This data and its trend can be valuable aid introubleshooting the system and predicting the need for asystem capacity test.

Prior to starting the periodic maintenance activity assurethat all required maintenance tools and equipment andsafety equipment is available and functional. Notify any-one who will be affected by the intended maintenance ortroubleshooting activity.

Also, all units in the battery should be numbered so as tofacilitate the recording and analysis of data unique to eachunit.

Required Maintenance Tools and Equipment

At a minimum, the following tools and equipment arerequired to maintain and troubleshoot the AlphaCell VRLAbattery.

1. Digital voltmeter

2. Socket wrenches, insulated

3. Box end wrenches, insulated

4. Torque wrench calibrated in in.-lbs.

5. Rubber gloves

6. Full face shield

7. Plastic apron

8. Portable eyewash

9. Spill kit

10. Fire extinguisher

The following equipment is optional depending on the typeof maintenance to be performed.

1. Micro-ohm meter

2. Battery resistance, impedance or conductancetest set

3. 100 amp momentary load test set

4. System load bank (DC if to be performed at thebattery and AC if to be performed by loading a UPS output)

3

Periodic Maintenance Tasks and Schedule

Quarterly Maintenance

The following checks should be completed quarterly:

1. Assure the battery room is clean, free of debrisand well lighted.

2. Assure that all facility safety equipment isavailable and functional.

3. Measure and record the air temperature within the battery room.

4. Visually inspect the battery for:a. cleanliness.b. terminal damage or evidence of heating.c. container or cover damage.d. evidence of overheating.

5. Measure and record the battery system DC floatcharging voltage at the battery. Optionally measure and record the AC ripple voltage at this time also.

6. Measure the DC voltage from each polarity of thebattery to ground to detect any ground faults.

7. If possible, measure and record the battery pilotunit. Sense the temperature on the side of the unit in the center or at the negative terminal of the unit.

8. Measure and record the temperature of the batterypilot unit. Sense the temperature on the side of the unit in the center or at the negative terminal of unit.

9. Measure and record the individual unit DC floatcharging voltage.

10. Measure and record the System EqualizationVoltage.

Semi-Annual Maintenance1. Repeat the quarterly checks.

2. Optionally perform the 10 sec. high rate (e.g. 100amp) load test to assure the individual batteries are functional.

3. Optionally measure and record theresistance/impedance/conductance of the individual units to trend the condition of the individual units over time and to detect dramatic differences between individual units and the norm.

Annual Maintenance1. Repeat the semi-annual checks.

2. Retorque all the interunit connecting hardware tothe values noted in Table 2. This can be omitted if the connection resistance is measured and found to have not increased more than 20% from the value at installation.

Bi-Annual Maintenance

The battery should be capacity tested every two years at theservice load or at the battery rating related to the servicerequirements. Ideally, this will be the same rate at which itwas acceptance tested when originally installed. Once thebattery is found to be at 85% of rating, it should be capac-ity tested annually. Capacity testing instructions are foundin the bulletin “Acceptance and Capacity Testing”.

Data Analysis and Corrective ActionsThe data accumulated during the periodic maintenanceactivities should be recorded on a form such as shown inAppendix 1. Following is an explanation of how the datawould be interpreted and the corrective action to be taken.However, it must be recognized that this explanation is notall inclusive and the analysis and corrective action decisionmust be made by personnel familiar with VRLA batteriesand their operation and failure modes.

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Environment Ambient and Battery Temperature

While the VRLA battery will function at extremes of temper-ature, it is rated at 77˚F (25˚C) and the ideal operatingtemperature range for the VRLA battery is 70˚F (21˚C) to80˚F (27˚C). Operation at cooler temperatures will reducethe anticipated standby operating time while operation atwarmer temperatures will detract from the battery life andwill increase the potential of a thermal runaway condition.

The battery will experience a 50% reduction of life for each18˚F (10˚C) above 77˚F (25˚C). High ambient room temper-ature should be corrected through the use of appropriateventilation and air conditioning.

The VRLA battery should not be charged at temperaturesexceeding 122˚F (50˚C). A thermal runaway condition couldresult.

The individual batteries within the string should not exceedthe ambient temperature by more than 18˚F (10˚C). If theentire battery or individual units temperatures are experi-encing thermal runaway. In this situation the chargingcurrent should be terminated and the cause of the situationshould be determined and corrected.

If thermal runaway has occurred, the battery system shouldbe capacity tested and replaced if necessary.

Battery Visual Inspection

Container Cleanliness

It is important that the individual batteries be clean andproperly spaced. An accumulation of dirt or dust and mois-ture on the covers can produce a conductive path betweenthe terminals or to ground which could result in short cir-cuits or ground faults. When batteries are cleaned, theyshould be on open circuit. For cleaning, use a cloth mois-tened in a solution of bicarbonate of soda and water. Donot use cleaners of unknown solutions such as window orglass cleaners and solvents. Use of certain petroleumbased cleaners will damage the battery plastic containersand could cause them to crack and craze.

Container and Cover Damage

Should a crack or other penetration of the container or cover of a battery be noted, it should be replaced. A crackin the container could allow conductive electrolyte to wickfrom the battery and create a ground fault. A ground faultcould lead to melting and burning of the container.

A hole in the cover, even without wicking of the electrolyte,can also be a serious situation. The hole will allow dryingof the electrolyte in the subject cell resulting in an eventualhigh resistance and heating of the subject cell.

Containers which are severely swollen and permanentlydeformed have been overheated and experienced thermalrunaway. Thermal runaway will also cause the batteries togas and dry out and will damage the plates. In this case,the entire battery string should be replaced.

Terminals

Bent or otherwise damaged terminals can produce highresistance connections or can hide a fracture that couldfuse open under load. Batteries with damaged terminalsshould be replaced.

If the protective grease at a termination has melted andflowed onto the cover, it is an indication that the connec-tion has been hot and this is, in all probability, the result ofa loose or high resistance connection. In this situation theconnection should be disassembled, inspected for damage,cleaned and properly reassembled.

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Battery System Float Charging Voltage

The recommended battery system float charging voltage forthe AlphaCell VRLA batteries with a specific gravity of1,280 to 1,300 is equal to the number of cells in the systemmultiplied by the range of 2.25 to 2.30 volts per cell at 77˚F(25˚C). For example, a string of 3 each 12 volt (6 cell) bat-teries should be float charged within the range of 40.5 to41.4 VDC (180 cells X 2.25 V/C minimum and 180 cells X2.30 V/C maximum) at 77˚F (22˚C).

When temperature extremes are encountered the floatcharging voltage should be temperature compensated. Thetemperature compensation coefficient is -0.0028 V/C per ˚F(-0.005 V/C per ˚C).

For example, if the battery normal temperature is 90˚F (13˚above 77˚F) the average float charging voltage rangeshould be reduced 0.036 V/C (13˚ X 0.0028 V/C per ˚F) tobetween 2.21 and 2.26 V/C. For a 18 cell battery this wouldbe 39.78 to 40.86 VDC. This will help reduce the potentialfor thermal runaway at elevated temperatures.

If the battery operates at “cold” temperatures, for example,50˚F (17˚ below 77˚F), the charging voltage can beincreased to improve recharge time. For example, thecharging voltage range could be increased by -17˚ X -0.0028 V/C per degree or 0.048 V/. For the 180 cell stringthis would be 413.6 to 422.6 VDC.

If the battery is undercharged for a period during whichthere have been multiple discharges, the battery will notfully recharge following each discharge and it will provideprogressively lower capacity. This condition may be cor-rectable with an extended equalization charge (eg. 48 to 72hours). However, if the situation has continued for too longa time, irreversible sulfation of the plates may haveoccurred and the battery may have to be replaced.Extended overcharging will cause excessive float current,corrosion of the plate grids, gassing and drying of the lim-ited amount of electrolyte. This constitutes prematureaging of the battery and loss of capacity.

Severe overcharging for extended periods can induce athermal runaway condition. This would also necessitatereplacement of the battery system.

While measuring the battery system DC float charging volt-age it may also be convenient to measure the AC ripplevoltage appearing across the battery system. If the AC rip-ple voltage is a sinusoidal waveform the maximum readingshould be less than 0.5% Vrms of the DC float voltage. Inthe case of 18 cell string floating at 41.4 VDC, this is 2.07Vrms. When measuring the ripple with an oscilloscope, themaximum p-p value should be 1.5% of the float voltage or6.2 Vp-p when floating at 41.4 VDC.

Excessive AC ripple voltage across the battery could causegassing and heating of the battery which would result inreduced life.

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2.20 2.25 2.30 2.35 2.40 2.45

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Battery System Float Charging Current

If the DC float current can be measured, it can provide an indication of the proper current acceptance of the batterysystem. Depending on the charging voltage per string andthe temperature, the float current per string should beapproximately that shown in Figure 3. The float current willapproximately double for each 18˚F (10˚C) above 77˚F(25˚C).

Figure 3Float Current vs. Voltage

If the DC float current is zero there is an open circuit in thebattery string. If the float current is higher than anticipat-ed, it may be due to elevated temperature of the battery orshorted cells within the string. In either case the causeshould be determined and corrected. Elevated tempera-tures and shorted cells are both situations which can leadto thermal runaway.

Individual Battery Float Charging Voltage

While the battery string may be charged at an average of between 2.25 and 2.3 volts per cell, not all cells will floatat the exact average voltage. Each cell has somewhat dif-ferent impedance and rate of oxygen recombination andwill therefore exhibit a slightly different float voltage at thesame float current. For example, all the 12 volt batteries in

a string charged at 2.3 volts per cell will not float at 13.9VDC but may vary from 13.3 to 14.5 and still be normal. Ifthe system is equalized for 24 hours upon installation, orwith an extended time in float service, this spread in floatvoltage will normally decrease.

Table 1 indicates the minimum and maximum DC floatvoltages to be measured across batteries in series string ofan indication of shorted cell. If an individual unit meas-ures too high, it may be an indication of increased resist-ance within the cell. If one unit measures very high whilethe balance of the units in the string indicate near theopen circuit value, the high voltage cell may have an opencircuit.

Shorted cells within the string will lead to increased volt-age applied to the remaining good cells in the string andhigher float current. For example, a 24 cell string chargingat 55.2 VDC (2.3 V/C) which has 2 shorted cells will becharging the remaining 22 cells at 2.5 V/C (55.2 VDC/22cells) and the resulting increase in float current is sure toresult in eventual thermal runaway.

A battery with a shorted or open cell can usually be con-firmed by comparing the impedance of the individual unitsor by comparing the AC ripple voltage measured across theindividual units.

Do Not perform a high rate load test on batteries that aresuspected of having a shorted or open cell. This would behazardous since a spark internal to the cell could ignite theinternal gases.

A battery suspected of having a shorted or open cell shouldbe removed and replaced immediately.

More information concerning the measurement and inter-pretation of individual battery float voltages is contained inthe pamphlet “Integrity Testing”.

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120

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High Rate Momentary Load Test

The high rate momentary load test is a functional test of the individual battery within the series string. It does notreplace a capacity test but it does not replace a capacitytest but it does indicate if the battery is functional at leastup to the ampere capability of the test load. A typical loadused for batteries in the 20 to 200 ampere range is 100amperes. The voltage of the unit 10 seconds after applica-tion of the test load should be at least 1.7 V/C average(10.2, 8.5 and 5.1 VDC for 12, 10 and 6 volt batteriesrespectively) or the battery should be suspected of beingopen, shorted, discharged or of very high resistance andlow capacity.

Never perform the high rate momentary load test on a bat-tery suspected of having a shorted or open cell. Full faceprotection should always be worn during this test, since aspark internal to a cell could ignite the residual gasseswithin the cell.

More information concerning this test and the minimumvoltages to be expected by part number is contained in thepamphlet “Integrity Testing”.

Barrey Impedance Testing

The normal wearout mode of the VRLA battery includes cor-rosion of the plate grids, deterioration of the plate activematerial and some drying of the electrolyte. Abnormal fail-ure modes would include deterioration of the conductivepath and excessive drying of the electrolyte. Theseprocesses will all increase the resistance of the affectedcells and periodic measurement of the impedance, resist-ance or conductance of the cells and trending of this datacan indicate string uniform gradual degradation and lossof capacity with time. This is shown in Figure 4.

Rapid changes in individual units may indicate shorted,open and drying cells and cells with deteriorating conduc-tive paths.

When an AC ripple voltage appears across a string of bat-teries it will be subdivided across the individual units inthe string proportional to their relative resistance.

Figure 4VRLA Battery Impedance and Conductance vs. Capacity and Age

Therefore in the absence of an impedance, resistance orconductance test set, the AC ripple voltage across the indi-vidual units can be measured with a DVM and compared toeach other and the norm as an indication of their relativeresistance and condition.

If the resistance of the batteries has increased by 30%over that when it was new, the battery should be furthertested to determine the cause and if necessary the batteryor system should be capacity tested to assure reliability.

More information on this topic is contained in the pamphlet“Impedance and Conductance Testing”.

Interunit Connecting Resistance

High resistance in the interunit connections and loose con-necting hardware can cause excessive voltage drop duringdischarge resulting in reduced operating time and in theextreme case even cause melting of the battery terminalsand potentially a fire.

The contacting surfaces of all connections should bebrushed clean, removing all lead oxide and contamination,protected with a special anti-oxidation grease, and tight.

8

%100 RATED CAPACITY

IMPEDENCE @ 60 Hz

CONDUCTANCE

The connection hardware may loosen somewhat with timeand repeated cycling of the battery system. The connectionhardware should be retorqued to the value indicated for thebattery part number as shown on the relevant data sheet.A summary of the battery terminal types and the recom-mended torque values is given in Table 2.

Performance and Capacity Testing

When the battery degrades to 80% of its rating it should bereplaced. That is, if a battery system could support 100amperes for 1 hour when new, it should be replaced when itcan only support 80 amperes for the same 1 hour period. If100 amperes is the actual load and this must be supportedfor a minimum of one hour, the battery should have beenoriginally sized to provide 125 amperes for the one hourwhen new. This sizing factor of .125 is referred to as theaging factor when originally sizing the battery.

When the battery capacity declines to 80% of rating it is anindication that the plate grids are corroded and expanded;that the plate active material has deteriorated and that thedrying of the electrolyte has occurred. The battery shouldbe removed from service and replaced at this time.

Naturally, the other criteria for battery replacement is whenit no longer supports the load for the minimum requiredtime — even if the battery is still greater than 80% of rat-ing. However, even at minimal load, the battery should notremain in service beyond that point when it is at 80% ofrating.

The VRLA batteries are rated at 77˚F (25˚C). it is importantto recognize that operation at lower temperatures, while itdoes not harm the battery, will reduce the operating time.Performance derating factors for reduced temperature arefound in the pamphlet “Acceptance and Capacity Testing”.

Continuous operation at elevated temperatures will resultin accelerated aging of the battery. For each 18˚F (10˚C)above 77˚F (25˚C) the battery will age at twice the normalrate. Additional information on this topic is found in thepamphlet “Life Expectancy and Temperature”.

Summary of Periodic Maintenance for VRLA Batteries

The VRLA battery is maintenance free only as related to theelectrolyte. For assurance of the battery reliability it is stillimportant to perform the recommended periodic mainte-nance. The recommended periodic maintenance, whetherperformed manually or via automated monitoring systems,is deigned to determine the gradual degradation of the sys-tems capacity and to detect any abnormal system or indi-vidual battery condition which could impact system relia-bility.

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Table 1AlphaCell VRLA Battery Symptoms and Solutions

Possible Possible CorrectiveSymptom Causes Result Actions

Capacity Test Results

Reduced operating time at 77˚Fwith smooth voltage decline.

Reduced operating time at 77˚Fwith step voltage decline or voltageplateaus.

Excessive initial voltage drop evento the point of dropping load in thefirst several seconds.

Temperature Checks

Elevated room temperature.

Elevated battery temperature.

High Current recharge.

Normal wear out.

Individual low capacity cells.

Battery is cold.

Cabling is too small.

High resistance connections.

Battery is undersized.

Shorted cells.

Lack of adequate airconditioning/ventilation.

Elevated room temperature.

Inadequate cabinet ventilation.

Discharge—Charge cycle.

High Charging voltage.

Shorted cells.

Eventual failure to support the loadfollowed by potential for shortedcells.

Reversed cells during discharge—reversed cells will become very hotand will not fully recharge.

Excessive voltage drop.

Excessive voltage drop.

Cells will become hot, could developthermal runaway; internal arcingcould result in explosion.

Reduced battery life.

Reduced life and potential thermalrunaway.

Reduced life and potential thermalrunaway.

Can be normal if not exceeding 18˚F(10˚C) increase.

This combination can lead to thermal runaway.

Replace battery system when at80% or rated capacity or before.

Replace the isolated low capacitybatteries.

Heat the battery.

Run parallel cables.

Clean and reassemble connections.

Add required parallel strings.

Replace isolated units with shortsand evaluate entire string.

Cool the room or accept reducedbattery life.

Improve room air conditioning.

Improve cabinet ventilation andtemperature.

Limit recharge current.

Limit recharge current.

Reduce to within specifications.

Replace shorted cells and evaluatetotal string.

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Table 1AlphaCell VRLA Battery Symptoms and Solutions continued


Visual Battery Checks

Cover / Container crack.

Cover / Container explosion.

Burned area on container.

Permantently defromed (swollen)container.

Rotten egg odor.

Melted grease at terminals

Corrosion at terminals.

Handling or impact damage.

Ignition of cell internal gasses dueto external source, fusing or inter-nal conductive path, or internalspark due to shorting. This poten-tial exists for batteries not main-tained and continued in servicebeyond useful life.

Crack in container wicking elec-trolyte to grounded rack, etc.Ground fault.

Thermal runaway possibly causedby high temperature environment,overcharging, excessively highrecharge current, shorted cells or aground fault or a combination ofthese items.

Possible caused by high tempera-ture environment, overcharging,excessively high recharge current,shorted cells or a ground fault or acombination of these items.

Connections were hot probably dueto excessive resistance caused byloose connection, dirty contact sur-faces or corrosion within the con-nection.

There is possibly either residualelectrolyte from manufacturing orelectrolyte leaking from the batteryterminal seal that is attacking theinterunit connector.

Cell dryout or ground fault.Potential internal gas ignition.

Personal injury and equipmentdamage at time of explosion.

Failure to support load.

Could result in personal hazard dueconductive path to rack, etc.

Could result in smoke or batteryfire.

Could result in a thermal runaway.

Could result in the emission ofhydrogen sulfide which isdetectable as a rotten egg odor,battery fire and inability to supportthe load.

Odor is a product of thermal run-away.

Excessive voltage drop perhapsleading to short operating time ordamaged terminals.

In extreme case, could lead to melt-ed terminal and ignition of the bat-tery cover.

Increased connection resistanceand resulting increase in the conec-tion heating and voltage drop athigh rate discharge.

Replace damaged unit.

Replace damaged unit and evalu-ate the balance of string.

Clear the ground fault and replacedefective unit. Evaluate balance ofthe string.

Repalce the battery system and cor-rect the items leading to the ther-mal runaway condition.

Replace the battery system and cor-rect the items leading to the ther-mal runaway.

Clean and reaasemble the connec-tion if damaged.

Replace any battery with damagedterminals.

Disassemble connection, clean,coat connecting surfaces and ter-minal area and seal with anti-oxi-dation grease and appropriatelyreassemble the connection. If leak-age about the terminal area isobvious, the battery should bereplaced.

11



DC Volatge Checks

System Float voltage greater than2.3 V/C average 77˚F (25˚C).

System float voltage less than 2.25V/C average at 77˚F (25˚C).

System equalize voltage is greaterthan 2.4 V/C average

System equalize voltage is lessthan 2.4 V/C average.

Individual battery float voltage lessthan 2.2 V/C average. 13.3 VDC for 6 cell battery.11.1 VDC for 5 cell battery.6.6 VDC for 3 cell battery.

Individual battery float voltagegreater than 2.42 V/C average.14.5 VDC for 6 cell battery.12.1 VDC for 5 cell battery.7.3 VDC for 3 cell battery.

DC voltage measured betweeneither of the battery system outputterminals and ground (rack) or aground fault indicated by automaticmonitoring equipment.

Charger output set incorrectly.

Charger output set incorrectly.

Charger equalization voltage is setincorrectly.

Charger equalization voltage is setincorrectly.

Potentially the individual batteryhas a shorted cell.

Could be verfied with an impedanceor conductance check.

Potentially there may be open cellin the individual battery. This canbe confirmed by checking for zerofloat current or checking for a veryhigh impedance of the battery.

Damaged battery container allow-ing electrolyte to wick out to thegrounded surface (rack).

Overcharging will cause excessivegassing and drying of the elec-trolyte and will contribute to poten-tial thermal runaway.

Undercharging will result in a grad-ual loss of operating time andcapacity with successive dischargecycles. if allowed to persist, anirreversible level of lead sulfate willdevelop on the plates with theresult of a permanent loss ofcapacity.

Overcharging will cause excessivegassing and drying of the elec-trolyte and will contribute to poten-tial thermal runaway.

Equalization and boost chargingwill be less effective and willrequire extended time.

Reduced operating time under load.Increased float current. Heating ofcell during discharge. Contributesto potential thermal runaway.

Failure to support the load. Couldresult in an internal arc whichcould ignite the gasses within thecell.

Personnel shock hazard which couldresult in serious injury or electrocu-tion.

Potential burning of the containerat damaged area or battery fire.

Reset the charger output voltage tothe recommeded value.

Reset the charger output voltage tothe recommeded value.

Equalize the battery system from 48to 72 hours and perform a capacitytest. If capacity loss is permanent,replace the total battery system.

Reset the charger output voltage tothe recommended value.

If possible, reset the charger outputvoltage to the recommended valueor accept longer equalization time.

Replace the individual battery.

Replace the individual battery.

Determine the source of the groundfault and replace the battery.

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AC Ripple Volatage Checks

AC ripple (p-p) voltage on the sys-tem is greater than 4% of the valueof the DC float voltage.

Individual battery in string exhibitsAC ripple voltage of twice that ofthe other typical batteries in string.

Float Charging Current Checks

Float current to the string is zero.

Float current exceeds 3.0 mil-liamperes per ampere hour of ratedcapacity at 77˚F (25˚C) at floatvoltage.

High Rate 10 Second Load Test

Terminal voltage is marginallybelow the minimum voltage speci-fied for 10 sec. point.

Terminal voltage is significantlybelow the minimum voltage speci-fied for 10 sec. point.

Poor filtering of the charger output.

Battery with the high AC ripple volt-age has a proportionately higherimpedance and should be furtherevaluated for performance. Subjectbattery could have a deterioratingconductive path or a dry, shorted oropen cell.

A battery or connection in the seriesstring is open. This can be verifiedvia the float voltage check or ACripple voltage or impedance checkof the individual batteries.

Batteries are not yet fullyrecharged.

Batteries are above 77˚F (25˚C).

Potentially shorted cells in battery.

Depending on the degree, the bat-tery may be entering or in thermalrunaway.

Battery is perhaps not fully chargedor is an older battery that has beenin service and is of somewhat lowercapacity.

battery is discharged of batteryconductive path, plate grid oractive material or electrolyte vol-ume deterioration.

Shorted

Open cells.

Excessive AC ripple could cause thebattery to cycle at the ripple fre-quency and result in heating anddeterioration of the plate activematerial.

Reduced operating time.

Potential conditions could be con-ductive to thermal runaway.

Failure to support the load. If aninternal arc should occur duringdischarge, it could ignite thegasses internal to the cell.

If there is a open/loose connectionin the external conductive path, itcould damage the terminationunder load.

Not at 100% of capability.

Conducive to thermal runaway.

Conducive to Thernal runaway.

Thermal runaway results in eventu-al meltdown of the battery and thepotential of hydrogen sulfide emis-sions and fire.

Perhaps reduced operating time.


Conducive to thermal runaway.

Will not support load.

Improve the charger output filtering

Verify the battery condition andreplace as required.

Replace the battery with the opencell or repair the open/loose exter-nal connection.

Determine the specific cause andtake necessary corrective action.

Fully recharge the battery.

Charge and retest battery or replaceas required.

13



Battery Impedance/ Conductance Test

Impedance / resistance increase by50% from original values when newor conductance decline to 50% orthe value when new.

Connection Hardware Resistance/ Tightness Check

Connection resistance increase of20% or more from original value.

Connection hardware tightness isless than the specified “retorque”value.

Battery is discharged or Batterycondictive path, plate grid or activematerial or electrolyte volume dete-rioration.

Shorted cells.

Open cells.

Repetitive cycles resulting in heat-ing and cooling of connection canresult in relaxation of torque andincrease in connection resistance.

Contamination within the connec-tion can result in corrosion andhigh terminal resistance.

Repetitive cycles resulting in heat-ing and cooling of connection canresult in relaxation of torque andincrease in connection resistance.


Conductive to thermal runaway.

Will not support load.

Loose connections can result inheat damaged or melted terminalsduring high rate discharge.

Excessive voltage drop during highrate discharge and resultingreduced operating time.

Loose connections can result inheat damaged or melted duringhigh rate discharge.

Charge and retest battery or replaceas required.

Retorque the connection asrequired.

Correct the source of contamina-tion, clean the contact surfaceareas, grease the contact surfaceswith anti-oxidant grease andresemble.

Retorque the connection asrequired.

14

Tabl

e 2

Bat

tery

Par

amet

ers

by P

art

Num

ber

Annu

alAv

erag

eAv

erag

eAm

pere

s8-

Hour

20-H

our

Typi

cal

Typi

cal

Typi

cal

Alph

aCel

l Re

torq

ueOp

enFl

oat V

olta

geEq

ualiz

atio

nto

1.7

5 V/

CAm

pere

Ampe

reIm

peda

nce

Cond

ucta

nce

10 S

ec.

VRLA

Bat

tery

Ty

peIn

ch-

Circ

uit

Rang

eVo

ltage

15 M

inut

eRa

te to

Rate

to@

60H

z7H

zVo

ltage

Part

No.

Term

inal

Bolt

Size

Poun

dsVo

ltage

(vol

ts/u

nit)

(vol

ts/u

nit)

Rate

1.75

V/C

1.75

V/C

ohm

sm

ohm

s@

100

am

p

160A

Lg. L

1/4”

-20

5212

.84

13.5

to 1

3.8

14.4

295

9.90

4.40

0.00

4014

50+

/-10

011

.616

5GLg

. L1/

4”-2

052

12.8

413

.5 to

13.

814

.430

510

.04.

300.

0055

900+

/-10

011

.216

5GXL

Lg. L

1/4”

-20

5212

.84

13.5

to 1

3.8

14.4

305

10.0

4.30

0.00

5590

0+/-

100

11.2

180G

Lg. L

1/4”

-20

5212

.84

13.5

to 1

3.8

14.4

331

10.8

4.68

0.00

5010

50+

/-20

011

.318

0GXL

Lg. L

1/4”

-20

5212

.84

13.5

to 1

3.8

14.4

331

10.8

4.68

0.00

5010

50+

/-20

011

.3

UPS1

2-10

0Sm

. Fla

g1/

4”-2

032

12.8

413

.5 to

13.

814

.444

.33.

01.

30.

0075

+/-

.000

760

0+/-

3011

.0UP

S12-

140

L1/

4”-2

032

12.8

413

.5 to

13.

814

.471

.53.

751.

60.

0046

+/-

.001

095

0+/-

7511

.5UP

S12-

170

L1/

4”=

2032

12.8

413

.5 to

13.

814

.481

.65.

752.

500.

0060

+/-

.001

098

0+/-

7511

.5UP

S12-

200

L1/

4”-2

032

12.8

413

.5 to

13.

814

.410

45.

62.

40.

0055

+/-

.001

1050

+/-

5011

.5UP

S12-

270

L1/

4”-2

032

12.8

413

.5 to

13.

814

.414

08.

63.

750.

0030

+/-

.000

514

50+

/-75

11.6

UPS1

2-31

0Lg

. L1/

4”-2

052

12.8

413

.5 to

13.

814

.415

79.

94.

40.

0027

+/-

.005

1750

+/-

100

11.6

UPS1

2-37

0Lg

. L1/

4”-2

052

12.8

413

.5 to

13.

814

.418

511

.05.

00.

0024

+/-

.000

319

75+

/-00

11.8

UPS1

2-47

5In

sert

1/4”

-20

110

12.8

413

.5 to

13.

814

.421

515

.96.

90.

0027

+/-

.000

316

00+

/-10

011

.8UP

S12-

620

XLg.

L1/

4”-2

060

6.42

6.75

to 6

.90

7.20

312

22.0

10.0

0.00

12+

/-.0

0221

00+

/-10

05.

9

TEL1

2-30

Inse

rt10

-32

UNF

2512

.84

13.5

to 1

3.8

14.4

67.2

3.81

1.65

0.00

62+

/-.0

010

760+

/-75

11.2

TEL1

2-45

Inse

rt10

-32

UNF

2512

.84

13.5

to 1

3.8

14.4

81.6

5.75

2.5

0.00

60+

/-.0

010

900+

/-50

11.5

TEL1

2-70

Inse

rt1/

4”-2

011

012

.84

13.5

to 1

3.8

14.4

131

8.63

3.75

0.00

36+

/-.0

005

1400

+/-

100

11.8

TEL1

2-80

Inse

rt1/

4”-2

011

012

.84

13.5

to 1

3.8

14.4

144

9.9

4.4

0.00

33+

/-.0

005

1450

+/-

100

11.7

TEL1

2-90

Inse

rt1/

4”-2

011

012

.84

13.5

to 1

3.8

14.4

162

115.

00.

0032

+/-

.000

315

90+

/-10

011

.9TE

L12-

105F

FT In

sert

1/4”

-20

110

12.8

413

.5 to

13.

814

.416

812

.55.

00.

0030

+/-

.000

315

95+

/-10

011

.85

TEL1

2-12

5In

sert

1/4”

-20

110

12.8

413

.5 to

13.

814

.421

515

.96.

70.

0027

+/-

.000

316

00+

/-10

011

.8TE

L12-

180

Inse

rt1/

4”-2

075

6.42

6.75

to 6

.90

7.20

312

22.0

10.0

0.00

15+

/-.0

002

2100

+/-

100

5.9

MPS

12-3

3L

1.4”

-20

3212

.84

13.5

to 1

3.8

14.4

67.2

3.81

1.65

0.00

7+/-

.001

076

0+/-

7511

.2M

PS12

-50

L1.

4”-2

032

12.8

413

.5 to

13.

814

.481

.65.

752.

500.

006+

/-.0

010

900+

/-50

11.5

MPS

12-7

5L

1.4”

-20

3212

.84

13.5

to 1

3.8

14.4

131

8.63

3.75

0.00

5+/-

.000

514

00+

/-10

011

.8M

PS12

-88

Lg. L

1.4”

-20

5212

.84

13.5

to 1

3.8

14.4

144

9.90

4.40

0.00

4+/-

.000

315

90+

/-10

011

.7M

PS12

-100

Lg. L

1.4”

-20

5212

.84

13.5

to 1

3.8

14.4

162

11.0

5.00

0.00

35+

/-.0

003

1600

+/-

100

11.9

15

Comments:

Room Visual Checks: ________________________________________________________________________________________________________________

_______________________________________________________________________________________________________________________________

Battery Visual Checks: _______________________________________________________________________________________________________________

Appendix 1AlphaCell VRLA Battery SystemHistorical Data and System Status

Company: ______________________________________________________ System Float Charging Voltage: _____________________ VDC: _____________

Location: ______________________________________________________ Date Batteries Installed:____________________________________________

Supervisor in Charge:______________________________________________ Load (K.W. or Ampere): _____________________________________________

Type Charger/Load: _______________________________________________ System Equalize Voltage: ___________________________________________

Unit Part Number: __________________________ Cells/Unit:______________ Room Temperature: ________________ Unit Temperature Range:_____________

Date: Date:

Impedance ImpedanceUnit Charging Conductance 10 Sec. Vmin. Connection Unit Charging Conductance 10 Sec Vmin. ConnectionNo. Volts-Unit AC Millivolts @ 100 Amps Resistance No. Volts-Unit AC Millivolts @ 100 Amps Resistance

1 31

2 32

3 33

4 34

5 35

6 36

7 37

8 38

9 39

10 40

11 41

12 42

13 43

14 44

15 45

16 46

17 47

18 48

19 49

20 50

21 51

22 52

23 53

24 54

25 55

26 56

27 57

28 58

29 59

30 60

16

United StatesAsia PacificLatin AmericaAlpha Technologies3767 Alpha WayBellingham, WA 98226Tel: 360-647-2360Fax: 360-671-4936Web: www.alpha.com

CanadaAlpha Technologies4084 McConnell CourtBurnaby, B.C. V5A 3N7Tel: 604-430-1476Fax: 604-430-8908

United KingdomAlpha TechnologiesCartel Business EstateEdinburgh WayHarlow, Essex CM20 2DUTel: +44-1279-422110Fax: +44-1279-423355

GermanyAlpha TechnologiesHansastrasse 8D-91126 SchwabachTel: +49-9122-79889-0Fax: +49-9172-79889-21

Middle EastAlphatecP. O. Box 64683307 Limassol, CyprusTel: +357-5-375675Fax: +357-5-359595

AustraliaAlpha TechnologiesUnit 6, Anella AvenueCastle Hill, NSW 2154Tel: +61-2-9894-7866Fax: +61-2-9894-0234

Investigate the [Power] of Alpha @ www.alpha.com

Due to continuing product development, Alpha reserves the right to change specifications without notice. Copyright ©2001 Alpha Technologies, Inc. All rights reserved. Alpha is a registered trademark of Alpha Technologies. 049-018-28-001 7/01

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