Valve-Regulated Lead-Acid (VRLA):

Transcription

1 Valve-Regulated Lead-Acid (VRLA): Gelled Electrolyte (Gel) ad Absorbed Glass Mat (AGM) Batteries EAST PENN Expertise ad America Workmaship I: INTRODUCTION TO VRLA How it Works Differece Betwee VRLA ad Flooded Ideal Applicatios II: III: IV: AGM & GEL BATTERIES AGM Batteries Gel Batteries Similarities Betwee Gel & AGM Differeces Betwee Gel & AGM Gel & AGM Battery Desig Advatages EAST PENN S VRLA BATTERY DESIGN East Pe s VRLA Features ad Beefits East Pe s Quality Assurace Checks GENERAL QUESTIONS ABOUT VRLA BATTERIES V: GLOSSARY OF TERMS I. INTRODUCTION TO VRLA Valve-Regulated Lead-Acid or VRLA, icludig Gel ad AGM (Absorbed Glass Mat) battery desigs, ca be substituted i virtually ay flooded lead-acid battery applicatio (i cojuctio with well-regulated chargig). Their uique features ad beefits deliver a ideal solutio for may applicatios where traditioal flooded batteries would ot deliver the best results. For almost three decades, East Pe has bee maufacturig valve-regulated batteries usig tried ad true techology backed by more tha 65 years experiece. East Pe produces a complete lie of Gel, AGM, ad covetioal flooded products for hudreds of applicatios. This diverse product offerig eables East Pe to be objective as to the advatages of each type of battery. East Pe s VRLA (Gel ad AGM) products have the reputatio of beig the highest quality VRLA batteries available. How it works A VRLA battery utilizes a oe-way, pressure-relief valve system to achieve a recombiat techology. This meas that the oxyge ormally produced o the positive plate is absorbed by the egative plate. This suppresses the productio of hydroge at the egative plate. Water (H 2 O) is produced istead, retaiig the moisture withi the battery. It ever eeds waterig, ad should ever be opeed as this would expose the battery to excess oxyge from the air. I additio to damagig the battery, opeig it also voids the warraty. The differece betwee VRLA ad traditioal flooded batteries Flooded electrolyte batteries do ot have special oe-way, pressure-relief valves, as they do ot work o the recombiatio priciple. Istead, flooded desigs utilize a vet to allow gas to escape. They cotai liquid electrolyte that ca spill ad cause corrosio if tipped or puctured. They should ot be used ear sesitive electroic equipmet. They ca oly be istalled upright. Flooded batteries lose capacity ad become permaetly damaged if: Left i a discharged coditio for ay legth of time (due to sulfatio). This is especially true of desigs that require water maiteace. Cotiually over-discharged (due to active material sheddig). This is especially true of automotive startig types. Ideal applicatios for VRLA batteries Deep Cycle, Deep Discharge Applicatios Marie Trollig Electroics Sailboats Electric Vehicles Wheelchairs/Scooters Golf Cars Portable Power Floor Scrubbers Persoel Carriers Reewable Eergy Village Power (Solar, Wid) Marie & RV Commercial Deep House Power Cycle Applicatios Stadby ad Emergecy Backup Applicatios UPS (Uiterrupted Cable TV Power Systems) Emergecy Lightig Computer Backup Reewable Eergy Frequecy Regulatio (Solar, Wid) Telephoe Switchig Other Applicatios Race or High O-Highway Truckig Performace Cars Off-Road Vehicles Wet Eviromets Marie & RV Startig Diesel Startig Cars ad Light Trucks Vehicles with with Accessories Start-Stop Systems

2 II. AGM & GEL BATTERIES VRLA techology ecompasses both gelled electrolyte or gel batteries ad absorbed glass mat or AGM batteries. Both types are regulated by special oe-way, pressure-relief valves ad have sigificat advatages over flooded lead-acid products. AGM (Absorbed Glass Mat) batteries The electrolyte i AGM batteries is completely absorbed i separators cosistig of matted glass fibers. This causes them to be spillproof, meaig they do t leak acid like a flooded desig if tipped o their side. The glass mats i AGM batteries are wrapped aroud the positive plate, which helps prevet damage from vibratio ad exted cyclig. The battery s groups are packed tightly i the case partitios also protectig its power producig compoets. AGM battery desigs ca have over twice the cycle life of a covetioal flooded product i the right applicatio. Gel or Gelled Electrolyte batteries The electrolyte i a Gel battery is permaetly locked i a highly viscous gelled state istead of the traditioal liquid form. Because there is o liquid-type electrolyte, it will ot leak out of the battery if tipped o its side. The thick, gelled electrolyte ad tightly packed groups also protect the battery s power producig compoets. Gel battery desigs have a superior deep discharge resiliecy ad ca deliver over two to three times the cycle life of a AGM product i the right applicatios. Similarities betwee Gel ad AGM VRLA techology Batteries utilize special oe-way, pressure-relief valves ad must ever be opeed. Requires o electrolyte maiteace ulike deep cycle flooded batteries that require frequet checkig ad adjustmet of electrolyte levels. Uses a recombiatio reactio to prevet the escape of hydroge ad oxyge gases ormally lost i a flooded lead-acid battery (particularly i deep cycle applicatios). Spillproof desig eables istallatio i virtually ay positio (upside-dow istallatio is ot recommeded). Has a higher tolerace agaist damage from deep discharge. These batteries have optimized amouts of electrolyte (which is also referred to as acid-starved ) so that they use the power i the acid before they use the power i the plates. This miimizes the destructive ature of ultra-deep discharges. Ultra-deep dischargig is what causes plate sheddig, which ca destroy a battery. Major differece betwee Gel ad AGM battery performace A Gel battery is better suited for super-deep discharge applicatios, which meas it ca withstad deeper discharges without damagig the battery s performace. However, due to the physical properties of the gelled electrolyte, Gel battery power declies faster tha a AGM battery as the temperature drops below 32ºF (0ºC). AGM batteries excel for high curret, high power applicatios ad i extremely cold eviromets. AGM batteries deliver a better dual purpose solutio for a combiatio of startig ad accessory power. Advatages of GEL ad AGM battery desigs KEY BATTERY BENEFITS GEL AGM Premium maiteace-free desig Air trasportable Spillproof costructio, wo t leak if tured sideways (most sizes) (may sizes) Yes Yes Miimizes termial corrosio Superior deep cycle life ad resiliecy to deep discharge damage (Best) (Good) Operates at severe agle or o side (wo t leak or spill) Low to o gassig Ideal for use aroud sesitive electroic equipmet Exteded shelf life, low self-discharge rate Ehaced rechargig efficiecy Resistace to vibratio Delivers the best combiatio startig, cyclig, ad deep cycle service (Good) (Best) Operatio i cold temperatures (Good) (Best) Cold egie crakig Low Yes III. EAST PENN S AGM & GEL VRLA BATTERY DESIGN Features ad beefits that make our VRLA batteries uique East Pe Expertise East Pe builds VRLA batteries to the highest stadards. Our mau facturig process features improved cotrols usig state-of-the-art computers ad the latest maufacturig techology ad equipmet. VRLA batteries produced by East Pe cosistetly meet the highest quality performace ad life stadards. Oe-Way, Pressure-Relief Valves A critical feature of ay VRLA battery is the quality of the sealig valve. Not oly must the valve safely release excessive pressure ad gas, but it must also keep the cell from beig cotamiated by the atmosphere. Oxyge cotamiatio will discharge ad evetually rui a VRLA battery. Our valves are UL recogized ad 100% tested. The beefit is reliable performace ad log life. Exclusive Gel Formula & Computerized Mixig Proper gel mixig is critical to life ad performace. Our state-of-the-art gel battery maufacturig facility is oe of the fiest i the world with a proprietary computerized gel mixig operatio. Our exclusive formula is mixed usig computer cotrol i every stage of the process. Computer cotrol delivers superior cosistecy for gel battery performace that is uequaled. Our temperaturecotrolled process ad specially desiged equip met 2

3 assures a homogeous gel. Our equipmet was desiged by our egieers specifically for gel mixig eve dow to the cotour of the tak bottoms ad feed pipe loca tios. Exclusive AGM Electrolyte ad Fillig Process Our AGM electrolyte cotais high purity sulfuric acid ad pure, demieralized ad deioized water. Avoidig impurities eables the battery to fuctio at the critical performace levels ecessary of the recombiat priciple utilized i a valve-regulated desig. This assures miimized gassig as well as water ad capacity loss providig loger service life ad sustaied performace. The AGM fillig process assures that each cell is saturated with the maximum amout of electrolyte that ca be held by the separators, without leavig excess electrolyte that could spill or leak. Multi-Staged Fillig ad Vacuumig Operatio Our gel process fills ad vacuums each cell several times. This multi-step process assures complete evacuatio of air ad complete gel-to-plate cotact. Our computerized process also weighs every SLI ad Statioary battery before ad after fillig as a check for proper gel levels. The result is a battery with more cosistet ad reliable performace. Our AGM toppig process assures that the maximum retaiable elec trolyte quatity is held withi the battery separators, to produce a complete electrolyte-to-plate cotact optimizig battery performace ad power. Gel Ultra-Premium, Glass Mat, Double Isulatig Separators Aother critical compoet is the separator, which isolates the positive from the egative plate. The separator must allow maximum charge flow betwee the plates for maximum performace. East Pe s Gel battery utilizes a separator with two layers: The first fiberglass sheet layer maitais compressio force over the etire surface of the positive plate prohibitig active material sheddig. The fiberglass strads from this layer also prevet sheddig by embeddig themselves ito the surface of the plates. This acts like reiforcig rods i cocrete. These extra reiforcemets lock the active material to prevet capacity degradatio for loger life performace. The secod layer is a porous orgaic polymer. The quatity ad size of the pores is optimized to balace the performace characteristics of the battery with its life characteristics. This layer has ribs o both sides to allow gel to reach the etire surface of both plates ad to maitai the correct plate spacig. Gel Polyester Elemet Wrap To prevet life-shorteig mossig i our gel batteries, we use a special polyester fiber sheet that is wrapped aroud the edge of each elemet, similar to the wrap i a idustrial battery. The result is loger service life. AGM Ultra-Premium Glass Mat Separators Variatios i separator properties ca be detrimetal to the AGM battery s fuctioal performace. East Pe uses glass mats that are egieered to have cosistecy ad a ideal balace of critical properties. This attetio to detail results i high performace ad log life. High absorptio ad retetio rate holds acid securely i glass fibers to prevet ueve saturatio ad acid stratificatio (see explaatio of acid stratificatio uder Acid Stratificatio Prevetio sectio). Thick, highly compressible mats provide padded protectio aroud plates ad absorb shock ad vibratio. This maitais compressio force over the etire surface of the positive plate prohibitig sheddig, which results i capacity degradatio. A AGM separator cotais o materials subject to failure from oxidatio. Low electrical resistace from electrolyte holdig fibers ad micro-porous compositio optimizes curret flow betwee plates for a more efficiet trasfer of power. Durable mats are wrapped aroud the bottom of the plate ad are wider tha the plates. This ihibits failures from direct cotact electrical plate shorts or shorts from the build-up of material o the battery elemets. Exclusive Alloy Compositios Our exclusive alloy compositios provide the optimal combiatio of loger shelf life, more power coductace, ehaced durability, ad superior corrosio resistace. By usig special grai refiers, we ca dramatically improve performace ad life. Calcium stregthes the grid for processig i the plat so that its itegrity is upheld i the battery to withstad the forces of vibratio ad shock i service. Heavy-Duty Grid Style Desig for Heavy-Duty Service East Pe uses a high-performace deep cycle grid desiged for durability. The thick grid wires ot oly lock the active material oto the grid, but also act as bus bars to collect ad direct the eergy to the termials. Acid Stratificatio Prevetio Acid stratificatio ca occur i covetioal flooded cells. Durig charge, acid is released at the plate surfaces. Durig discharge, acid is cosumed at the plate surfaces. Sice the cocetratio is ot uiform, diffusio (spotaeous mixig by radom molecular motios) begis. If this mixig occurred rapidly, stratificatio would ot occur, but it is relatively slow, allowig lighter parts of elec trolyte to float toward the surface ad heavier parts to sik toward the bottom. The top portio of the plates do ot perform as well i cotact with lower cocetratio electrolyte. The bottom portio of the plates do ot perform as well with the higher cocetratio ad will corrode prematurely. High voltage equalizatio chargig is sometimes used i flooded batteries to make gas bubbles that remix the elec trolyte. Immobilized gel or separator-absorbed electrolyte will ot float or sik withi itself whe a o-uiform cocetratio exists so it caot stratify. Therefore, o high-voltage equalizig charge is ecessary. Simply recharge at the recommeded recharge settigs. This meas loger life ad cosistet performace. Proprietary Case, Cover, ad Oe-Way, Pressure-Relief Valve We desig our ow highly fuctioal polypropylee cases, valves, ad covers. May are molded i our o-site, state-of the-art plastics moldig facility. This provides ultimate cotrol of our high performace desigs, quality ad delivery to our maufacturig plat, assurig you the highest quality battery ad most reliable service. 3

4 East Pe s Quality Assurace Checks Below are a few examples of the hudreds of quality checks that are performed o Gel or AGM battery types to assure total cofidece i the performace ad life of our batteries: Exteded Shelf Stad Test. Before shipmet, every battery is required to stad for a period of time ad edig voltages are aalyzed. This extra quality assurace step verifies that the batteries are optimized for electrical performace. Computer-Ehaced Fillig Cotrols. Durig this computerized process, batteries are moitored ad filled to exactig levels for precisio separator absorptio ad complete permeatio. Multi-Staged Fillig ad Vacuumig Process. Every battery is filled ad vacuumed several times durig this computerized process. Multi-staged vacuumig assures complete electrolyte-to-plate iterface. Computerized Polarity Check. Every battery is checked by computer aalysis for proper polarity. Discharge Test. High-precisio calibrated sesors allow computers to moitor the voltage drop durig this discharge to assure that every battery performs as desiged. Grid Castig Ispectios. Specified checks such as alloy samplig, lead pot temperatures, ladle temperatures, grid weight ad thickess aalysis assures pateted alloy bled ad precise coditios for proper grid formatio ad applicatio ito battery productio. Acid Mixig Checks. Regulatory acid temperature ad specific gravity moitorig optimizes battery performace ad logevity. Paste Mixig Moitorig. Computer-assisted formula moitorig ad extesive acid gravity ad temperature checks provide best attributes for paste adhesio, power absorptio ad delivery performace. Paste-to-Grid Applicatio Moitorig. Temperature, thickess, weight ad lie speed aalysis assures proper adhesio ad exteded service life. Curig Checks. Assures proper time, temperature, ad humidity to create the optimal eviromet to facilitate the curig process. Cast-O-Strap ad Assembly Audits. Moitors lead temperatures, lie speed, alloy samplig, weld quality, termial bur depth, ad leak testig all to esure the fial assembled product meets rigid specificatios ad stadards providig a solid costructio to support premium VRLA battery products. IV. GENERAL QUESTIONS ABOUT VRLA BATTERIES What do I eed to kow about VRLA battery chargig? All lead-acid batteries release hydroge from the egative plate ad oxyge from the positive plate durig chargig. VRLA batteries have oe-way, pressure-relief valves. Without the ability to retai pressure withi the cells, hydroge ad oxyge would be lost to the atmosphere, evetually dryig out the electrolyte ad separators. Voltage is electrical pressure (eergy per uit of charge). Charge (ampere-hours) is a quatity of electricity. Curret (amperes) is electrical flow (chargig speed). A battery ca oly store a certai quatity of electricity. The closer it gets to beig fully charged, the slower it must be charged. Temperature also affects chargig. If the right voltage is used for the temperature, a battery will accept charge at its ideal rate. If too much voltage is used, charge will be forced through the battery faster tha it ca be stored. Reactios other tha the chargig reactio also occur to trasport this curret through the battery maily gassig. Hydroge ad oxyge may be give off faster tha the recombiatio reactio. This raises the pressure util the oe-way, pressure-relief valve opes. The gas lost caot be replaced. Ay VRLA battery will dry out ad fail prematurely if it experieces excessive overchargig. Note: It is too much voltage that iitiates this problem, ot too much charge a battery ca be over-charged (damaged by too much voltage) eve though it is ot fully charged. Never istall ay lead-acid battery i a sealed cotaier or eclosure. Hydroge gas must be allowed to escape. Ca cotiual uderchargig harm a VRLA battery? I may respects, uderchargig is as harmful as overchargig. Keepig a battery i a udercharged coditio allows the positive grids to corrode ad the plates to shed, dramatically shorteig life. Also, a udercharged battery must work harder tha a fully charged battery, which cotributes to short life as well. A udercharged battery has a greatly reduced capacity. It may easily be iadvertetly over-discharged ad evetually damaged. Do VRLA batteries have a memory like Ni-Cad batteries? Oe of the major disadvatages of ickel-cadmium (i-cad) batteries is that after shallow discharge cycles, the uused portios of the electrodes remember the previous cycles ad are uable to sustai the required discharge voltage beyod the depth of the previous cycles. The capacity is lost ad ca oly be restored by slowly dischargig completely (geerally outside the applicatio), ad properly rechargig. VRLA lead-acid batteries do ot exhibit this capacity robbig effect kow as memory. 4

5 What are the safety precautios for VRLA batteries? Although all valve-regulated batteries have the electrolyte immobilized withi the cell, the electrical hazard associated with batteries still exists. Work performed o these batteries should be doe with the tools ad the protective equipmet listed below. Valve-regulated battery istallatios should be supervised by persoel familiar with batteries ad battery safety precautios. Protective Equipmet To assure safe battery hadlig, istallatio ad maiteace, the followig protectio equipmet should be used: Safety glasses or face shield (Cosult applicatio specific requiremets) Acid-resistat gloves Protective apros ad safety shoes Proper liftig devices Properly isulated tools Procedures Cosult user maual of specific applicatio for safety & operatig requiremets. The followig safety procedures should be followed durig istallatio: (Always wear safety glasses or face shield.) 1. These batteries are sealed ad cotai o free flowig electrolyte. Uder ormal operatig coditios, they do ot preset ay acid dager. However, if the battery jar, case, or cover is damaged, acid could be preset. Sulfuric acid is harmful to the ski ad eyes. Flush affected area with water immediately ad cosult a physicia if splashed i the eyes. Cosult MSDS for additioal precautios ad first aid measures. 2. Prohibit smokig ad ope flames, ad avoid arcig i the immediate viciity of the battery. 3. Do ot wear metallic objects, such as jewelry, while workig o batteries. Do ot store u-isulated tools i pockets or tool belt while workig i viciity of battery. 4. Keep the top of the battery dry ad clear of all tools ad other foreig objects. 5. Provide adequate vetilatio as regulated by Federal, State ad Local codes ad follow recommeded chargig voltages. 6. Extiguishig media: Class ABC extiguisher. Note: CO 2 may be used but ot directly o the cells due to thermal shock ad potetial crackig of cases. 7. Never remove or tamper with pressure-relief valves. Warraty void if vet valve is removed. Ca VRLA batteries be istalled i sealed battery boxes? NO! Never istall ay type of battery i a completely sealed cotaier. Although most of the ormal gasses (oxyge ad hydro ge) produced i a VRLA battery will be recombied ad ot escape, oxyge ad hydroge will escape from the battery i a overcharge coditio (as is typical of ay type battery). These potetially explosive gasses must be allowed to vet to the atmosphere ad must ever be trapped i a sealed battery box or tightly eclosed space! Does depth of discharge affect cycle life? Yes! The harder ay battery has to work, the sooer it will fail. The shallower the average discharge, the loger the life. It s importat to size a battery system to deliver at least twice the eergy required, to assure shallow discharges. Follow these tips for the logest life: Avoid ultra-deep discharges. The defiitio of ultra-deep discharge may vary with applicatio ad battery type. Do t leave a battery at a low stage of charge for a exteded legth of time. Charge a discharged battery as soo as possible. Do t cycle a battery at a low state of charge without regularly rechargig fully. Use the highest iitial chargig curret available (up to 30% of the 20-hour capacity per hour) while stayig withi the proper temperature-compesated voltage rage. HIGH VOLTAGE... RISK OF SHOCK. DO NOT TOUCH UNINSULATED TERMINALS OR CONNECTORS. SHIELD EYES EXPLOSIVE GASES CAN CAUSE BLINDNESS OR INJURY. DANGER NO. SPARKS FLAMES SMOKING SULFURIC ACID CAN CAUSE BLINDNESS OR SEVERE BURNS. FLUSH EYES IMMEDIATELY WITH WATER. GET MEDICAL HELP FAST. DO NOT REMOVE VENT VALVE. WARRANTY VOID IF VENT VALVE IS REMOVED. VENTILATE WELL WHEN IN AN ENCLOSED SPACE AND WHEN CHARGING. SEE INSTALLATION, MAINTENANCE AND OPERATION INSTRUCTIONS FOR IMPORTANT SAFETY PRECAUTIONS. REPAIR SHOULD BE PERFORMED ONLY.BY A QUALIFIED SERVICE TECHNICIAN. Califoria Propositio 65 Warig Batteries, battery posts, termials ad related accessories cotai lead ad lead compouds, ad other chemicals kow to the state of Califoria to cause cacer ad birth defects or other reproductive harm. Wash hads after hadlig. 5

6 What is a thermal ruaway? The appropriate charge voltage depeds o the battery temperatures. A warmer battery requires a reduced voltage. If the voltage is ot reduced, curret accepted by the battery icreases. Whe the curret icreases, the iteral heatig icreases. This ca rise to destructive levels if ot take ito cosideratio. Thermal ruaway ca be preveted with: Temperature compesatio moitorig at the battery ot at the charger. Limitig chargig currets to appropriate levels. Allowig for adequate air circulatio aroud the batteries. Usig timers or ampere-hour couters. Usig smart chargers that recogize the sigature of a thermal ruaway evet which will shut the charger dow. Why do some VRLA batteries have a cocave or covex appearace? CONCAVE APPEARANCE The gas pressure i a VRLA battery ca be lower tha ambiet pressure uder certai circumstaces. This partial vacuum will pull the cotaier walls ad cover iward. This may give the eds, sides of each cell, ad tops of each cell a oticeable cocave (iwardly dished) appearace. This is ormal. The product is ot defective. Its performace is ot compromised i ay way. I some situatios chargig will reduce or elimiate this appearace. Iteral gas pressure beig lower tha exteral pressure has several potetial causes that ca operate aloe or i combiatio. The recombiatio process cotiues after chargig eds cosumig most of the headspace oxyge decreasig iteral pressure. A icrease i exteral pressure will result from a decrease i altitude. Coolig the battery reduces the iteral gas pressure by cotractio ad also by causig some water vapor to retur to liquid form. Severe dischargig shriks the volume of the iteral materials. This leaves more volume for the gas to fill reducig the iteral pressure. CONVEX APPEARANCE To prevet the permaet loss of gases so that recombiatio has time to take place, each cell ca hold a iteral gas pressure above exteral pressure before vetig. Batteries with very large cells will slightly bulge as this ormal pressure builds. This is especially oticeable at higher temperatures because the polypropylee case is more pliable whe warm. Therefore, a certai amout of bulge is ormal. If a battery bulges severely o charge, this is ot ormal. It is a idicatio of a blocked valve or a overcharge situatio. Such a battery should be removed from service. V. GLOSSARY TERMS ACTIVE MATERIAL The porous structure of lead compouds that produce ad store electrical eergy withi a lead-acid battery. The active material i the positive plates is lead dioxide ad that i the egative is metallic spoge lead. Whe a electrical circuit is created, these materials react with sulfuric acid durig chargig ad dischargig accordig to the followig chemical reactio: PbO 2 + Pb + 2H 2 SO 4 = 2PbSO 4 + 2H 2 O. AGM (Absorbed Glass Mat) A type of o-wove separator material comprised almost etirely of glass microfibers that absorbs ad retais the electrolyte leavig o free electrolyte i the cell to spill. VRLA batteries made with this material are ofte referred to as AGM batteries. AMPERE (Amp, A) The uit of measure of the electro flow rate, or curret, through a circuit. AMPERE-HOUR (Amp-Hr, Ah) A uit of measure for a battery s electrical storage capacity, obtaied by multiplyig the curret i amperes by the time i hours of discharge. (Example: A battery that delivers 5 amperes for 20 hours delivers 5 amperes X 20 hours = 100 Amp-Hr of capacity.) BOOST CHARGE The process of esurig that the cells ad plates withi a battery are charged sufficietly for the battery to perform its desired fuctio. Boost chargig is typically doe for a short duratio at a high curret. CAPACITY The capacity of a battery is specified as the umber of Amp-Hrs that the battery will deliver at a specific discharge rate ad temperature. The capacity of a battery is ot a costat value ad is see to decrease with icreasig discharge rate. The capacity of a battery is affected by a umber of factors such as: active material weight, desity of the active material, adhesio of the active material to the grid, umber, desig ad dimesios of plates, plate spacig, desig of separators, specific gravity ad quatity of available electrolyte, grid alloys, fial limitig voltage, discharge rate, temperature, iteral ad exteral resistace, age, ad life history of the battery. CONTAINER AND COVER The reservoir ad lid cotaiig the battery parts ad electrolyte made from impact ad acid resistat material such as polypropylee. CELL The basic electrochemical curret-producig uit i a battery, cosistig of a set of positive plates, egative plates, electrolyte, separators, ad casig. I a lead-acid battery the cell has a ope-circuit voltage of approximately 2-volts. There are six cells i a 12-volt lead-acid battery. CIRCUIT A electrical circuit is the path followed by a flow of electros. A closed circuit is a complete path. A ope circuit has a broke, or discoected, path. CIRCUIT (Series) A circuit that has oly oe path for the flow of curret. Batteries arraged i series are coected with egative of the first to positive of the secod, egative of the secod to positive of the third, etc. If two 12-volt batteries of 50 amperehours capacity each are coected i series, the circuit voltage is equal to the sum of the two battery voltages, or 24 volts, ad the ampere-hour capacity of the combiatio is 50 ampere-hours. 6

7 CIRCUIT (Parallel) A circuit that provides more tha oe path for the flow of curret. A parallel arragemet of batteries (usually of like voltages ad capacities) has all positive termials coected to a coductor ad all egative termials coected to aother coductor. If two 12-volt batteries of 50 ampere-hour capacity each are coected i parallel, the circuit voltage is 12 volts, ad the ampere-hour capacity of the combiatio is 100 ampere-hours. COLD CRANK RATING The cold crak ratig refers to umber of amperes a lead-acid battery at 0 F (-17.8 C) ca deliver for 30 secods ad while maitaiig at least 7.2 volts (1.2 volts per cell). This is commoly referred to as CCA (Cold Crakig Amps). CONDUCTANCE The ability to trasmit curret i a circuit or battery. CORROSION The chemical or electrochemical reactio betwee a material, usually a metal, ad its eviromet that produces a deterioratio of the material ad its properties. The positive lead grids i a battery gradually corrode i service ofte leadig to battery failure. Battery termials are subject to corrosio if they are ot properly maitaied. CURRENT The rate of flow of electricity, or the movemet of electros alog a coductor. It is comparable to the flow of a stream of water. The uit of measure for curret is the ampere. CURRENT (ALTERNATING) (AC) A curret that varies periodically i magitude ad directio. A battery does ot deliver alteratig curret (AC). CURRENT (DIRECT) (DC) A electrical curret flowig i a electrical circuit i oe directio oly. A secodary battery delivers direct curret (DC) ad must be recharged with direct curret i the opposite directio of the discharge. CYCLE I a battery, oe discharge plus oe recharge equals oe cycle. DISCHARGING Whe a battery is deliverig curret, it is said to be dischargig. ELECTROLYTE I a lead-acid battery, the electrolyte is sulfuric acid diluted with water. It is a coductor that supplies water ad sulfate for the electrochemical reactio: PbO 2 + Pb + 2H 2 SO 4 = 2PbSO 4 + 2H 2 O. ELECTRONIC TESTER A electroic device that assesses the coditio of a battery through a ohmic measuremet such as resistace or coductace, typically without drawig large curret loads. ELEMENT A set of positive ad egative plates assembled with separators. EQUALIZATION CHARGE The process of esurig that the cells ad plates withi a battery are all at full charge ad that the electrolyte is uiform ad free of stratificatio. This is ormally doe by chargig the battery uder cotrolled coditios (charge curret, time ad upper voltage limits are usually specified). FORMATION I battery maufacturig, formatio is the process of chargig the battery for the first time. Electrochemically, formatio chages the lead oxide paste o the positive grids ito lead dioxide ad the lead oxide paste o the egative grids ito metallic spoge lead. GEL Electrolyte that has bee immobilized by the additio of a chemical aget, ormally fie silica, to prevet spillage. Batteries made with gelled electrolyte are ofte referred to as Gel batteries. Gel batteries are oe typical type of VRLA battery. GRID A lead alloy framework that supports the active material of a battery plate ad coducts curret. GROUND The referece potetial of a circuit. I automotive use, the result of attachig oe battery cable to the body or frame of a vehicle that is used as a path for completig a circuit i lieu of a direct wire from a compoet. Today, over 99% of automotive ad LTV applicatios, use the egative termial of the battery as the groud. HYDROMETER A device used to measure the stregth (i.e., the cocetratio of sulfuric acid i the electrolyte) of the electrolyte through specific gravity of the electrolyte. INTERCELL CONNECTORS Lead structures that coect adjoiig cells i series, positive of oe cell to the egative of the ext, withi a battery. LOAD TESTER A istrumet that draws curret (discharges) from a battery usig a electrical load while measurig voltage. It determies the battery s ability to perform uder actual discharge coditios. LOW WATER LOSS BATTERY A battery that requires little to o water additios uder ormal operatig coditios; also referred to as maiteace-accessible batteries. MAINTENANCE-FREE A battery that ormally requires o service waterig durig its lifetime of use. NEGATIVE Desigatig, or pertaiig to, electrical potetial. The egative battery termial is the poit from which electros flow durig discharge. OHM A uit for measurig electrical resistace or impedace withi a electrical circuit. OHM S LAW Expresses the relatioship betwee volts (V) ad amperes (I) i a electrical circuit with resistace (R). It ca be expressed as follows: V = IR Volts (V) = Amperes (I) x Ohms (R). If ay two of the three values are kow, the third value ca be calculated usig the above equatio. OPEN CIRCUIT VOLTAGE The voltage of a battery whe it is ot deliverig or receivig power. PLATES Thi, flat structures comprised of a grid ad active material. The grid supports the active material ad coducts electros out of the cell. Plates are either positive or egative, depedig o the active material they hold. POSITIVE Desigatig, or pertaiig to, a kid of electrical potetial; opposite of egative. A poit or termial o a battery havig higher relative electrical potetial. The positive battery termial is the poit to which electros flow durig discharge. PRIMARY BATTERY A battery that ca store ad deliver electrical eergy but caot be recharged. A lead-acid battery is NOT a primary battery. 7

8 RESERVE CAPACITY RATING The time i miutes that a ew, fully charged battery will deliver 25 amperes at 27 C (80 F) ad maitai a termial voltage equal to, or higher tha, 1.75 volts per cell. This ratig represets the time the battery will cotiue to operate essetial accessories if the alterator or geerator of a vehicle fails. RESISTANCE The oppositio to the free flow of curret i a circuit or battery. It is commoly measured i Ohms. SECONDARY BATTERY A battery that ca store ad deliver electrical eergy ad ca be recharged by passig direct curret through it i a directio opposite to that of discharge. A lead-acid battery is a secodary battery. SEPARATOR A porous divider betwee the positive ad egative plates i a cell that allows the flow of ioic curret to pass through it, but ot electroic curret. Separators are made from umerous materials such as: polyethylee, polyviyl chloride, rubber, glass fiber, cellulose, etc. SHORT CIRCUIT A uiteded curret-bypass i a electric device or wirig. Outside the battery a short circuit is established whe a coductive path is established betwee the two termials of a battery. Iside a battery, a cell short circuit is the result of cotact betwee the positive ad egative plates ad will cause a cell to discharge ad reder the battery useless. SPECIFIC GRAVITY (Sp. Gr. or SG) Specific Gravity is a measure of the electrolyte cocetratio i a battery. This measuremet is based o the desity of the electrolyte compared to the desity of water ad is typically determied by the use of a hydrometer (see Hydrometer). By defiitio, the specific gravity of water is 1.00 ad the specific gravity of the sulfuric acid electrolyte i a typical fully charged battery is Specific gravity measuremets are typically used to determie if the battery is fully charged or if the battery has a bad cell. STATE OF CHARGE The amout of deliverable low-rate electrical eergy stored i a battery at a give time expressed as a percetage of the eergy whe fully charged ad measured uder the same discharge coditios. If the battery is fully charged the State of Charge is said to be 100%. SULFATION The geeratio or coversio of the lead sulfate discharge i the plates to a state that resists ormal recharge. Sulfatio ofte develops whe a battery is stored or cycled i a partially discharged state at warm temperatures. TERMINALS The electrical structures o the battery to which the exteral circuit is coected. Typically, batteries have either top-termials (posts) or side-termials. Some batteries have both types of termials (dual-termial). VENTS Mechaisms that allow gasses to escape from the battery while retaiig the electrolyte withi the case. Flame arrestig vets typically cotai porous disks that reduce the probability of a iteral explosio as a result of a exteral spark. Vets come i both permaetly fixed ad removable desigs. VOLT The uit of measure for electrical potetial or voltage. VOLTMETER A electroic device used to measure voltage, ormally i a digital format. VOLTAGE DROP The et differece i the electrical potetial (voltage) whe measured across a resistace or impedace (ohms). Its relatioship to curret is described i Ohm s law. VRLA Valve Regulated Lead Acid battery. AGM ad Gel are the two types of VRLA batteries. These batteries have o free liquid electrolyte ad i the cell operate o the oxyge recombiatio cycle, which is desiged to miimize water loss. VRLA batteries feature valves that have a oe-way, pressure-relief desig. These low-pressure valves prohibit air eterig the cell while permittig gases to vet from the cell if ecessary. The pressure maitaied i the battery, though oly very slight, is required to facilitate the oxyge recombiatio reactio, which coverts the oxyge geerated at the positive plates back ito water. WATT The uit for measurig electrical power, i.e., the rate of doig work, i movig electros by, or agaist, a electrical potetial. Formula: Watts = Amperes x Volts. WATT-HOUR (Watt-Hr, WH) The uit of measure for electrical eergy expressed as Watts x Hours. STRATIFICATION The uequal cocetratio of electrolyte due to desity gradiets from the bottom to the top of a cell. This coditio is ecoutered most ofte i batteries recharged from a deep discharge at costat voltage without a great deal of gassig. Cotiued deep cyclig of a stratified battery will result i softeig of the bottoms of the positive plates. Equalizatio chargig is a way to avoid acid stratificatio. Lyo Statio, PA Phoe: Fax: Order Departmet Hotlie: E.P.M. Form No Rev. 10/ by EPM Prited i U.S.A. No part of this documet may be copied or reproduced, electroically or mechaically, without writte permissio from the compay.