Yuasa Battery Sales (U.K) Limited, Hawksworth Industrial
Contents
1. LEDC Input Indicator LED f P LED Charge Indicator BEI ON Joc Output The C V C C modules are protected from both the short reverse polarity connected to the battery Detailed circuiting of their D C output voltage and from being specifications are available on request 20 Solar Powered Chargers A battery is an indispensable component of any solar powered system designed for demand energy use Since solar cells have inherent constant voltage characteristics NP batteries can be charged directly from the solar array using a simple diode regulated circuit as shown in Figure 24 In designing a solar powered system consideration Should be given to the fact that in addition to normal periods of darkness weather conditions may be such that solar energy is limited or virtually unavailable for long periods of time In extreme cases a system may have to operate for 10 to 20 days with little or no power available for charging Therefore when selecting the correct battery for a solar application the capacity should be determined based upon maximum load conditions for the maximum period of time the system may be expected to be without adequate solar input In many instances the battery capacity will be 10 to 50 times greater than the maximum output of the solar panels Under these circumstances the maximum output of the solar array should be dedicated to charging the battery with no load sharing or interveni2. E lt Cr e A NYA NN i Y NAN A CC pases pieces N 30Ah EM ok ND ONNA INN NRT SN VAN OTN ONS OT N N 10 00 1000 00 Discharge Current Amps Date 05 10 99 DISCHARGE FILE NQA SHARED PETERWPDATA Batselch B Discharge Characteristics The curves shown in Figure 3 and the discharge current rates shown in Table 4 illustrate the typical discharge characteristics of Yuasa NP batteries at an ambient temperature of 25 The symbol C expresses the nominal capacity of the battery measured at a 20 Hour discharge rate Please refer to General Specifications on page 3 to determine the nominal capacity rating of specific NP models The standard industry practice to determine the nominal capacity of a valve regulated lead acid battery is to discharge the battery under test at its 20 Hour rate to a final voltage of 1 75 volts per cell Table 4 shows the different currents that can be drawn at various discharge capacity rates Table 6 shows that the rated nominal capacity of a battery is reduced
3. 41 C 106 F to 50 C 122 F Brief excursions i e few days at temperatures higher than the ranges recommended will have no adverse effect on storage time or service life However should the higher ambient temperature persist for one month or more the storage time must be determined by referring to the new ambient temperature Ideally NP batteries Should be stored in dry cool conditions Recharging Stored Batteries In general to optimise performance and service life it is recommended that NP batteries which are to be stored for extended periods of time be given a supplementary charge commonly referred to as a top charge periodically Please refer to the recommendations listed on page 24 under Top Charging 10 Figure 6 TEMPERATURE LIFE CHARACTERISTICS OF BATTERIES YEARS c 2 kep Lu o lt gt 30 40 TEMPERATURE Figure 6 shows extrapolated Service Life condition for be seen from figure 6 higher ambient temperatures will NP batteries at different ambient temperatures As can reduce service life _ 11 AVAILABLE CAPACITY MEASURED OPEN CIRCUIT VOLTAGE The approximate depth of discharge or remaining Capacity in a Yuasa NP battery can be empirically determined by referring to Figure 7 IMPEDANCE Figure 7 OPEN CIRCUIT VOLTAGE VS REMAINING CAPACITY V V V FOR 4V ANF ORC 215 SRM FOR 12V FOR 6V BATTERY BATTERY 14 0 7
4. As the temperature rises electrochemical activity in a battery increases and conversely decreases as temperature falls Therefore as the temperature rises the charging voltage Should be reduced to prevent overcharge and increased as the temperature falls to avoid undercharge In general in order to attain optimum service life the use of a temperature compensated charger is recommended The recommended compensation factor for NP batteries is 3mvV C Cell for float standby and 4mV C Cell cyclic use The standard centre point for temperature compensation is 20 C Figure 29 shows the relationship between temperatures and charging voltages in both cyclic and float standby applications Figure 29 RELATIONSHIP BETWEEN CHARGING VOLTAGE AND TEMPERATURE V 12V BATTERY V 6V BATTERY V CELL lt a gt c lt IE 20 68 30 40 50 60 86 104 122 140 F AMBIENT TEMPERATURE In practice where there are short term temperature fluctuations between 5 C and 40 C temperature compensation is not absolutely essential However it is desirable to set the voltage at a value shown in Figure 29 which as closely as possible corresponds to the average ambient temperature of the battery during its service life _ 25 When designing a charger equipped with temperature compensation the temperature sensor must sense only the temperature of the battery
5. M YUASA Yuasa Battery Sales U K Limited H awksworth Industrial Estate Swindon W iltshire SN 2 1EG Telephone Swindon 01793 645700 Fax 01793 645701 e mail enquiries yuasa sales co uk Website www yuasa battery co uk Yuasa Battery Europe GM Wanheimer Str 47 D 40472 D sseldorf Germany Telefon 0049 211 417900 Fax 0049 211 4179011 Issue D ate 01 12 99 INTRODUCTION Yuasa began development of the NP series of valve regulated lead acid batteries in 1958 Today s battery is the culmination of over 75 years of battery manufacturing experience ADVANCEMENTS The high energy density advanced plate technology sealed construction efficient performance and long service life combine to make Yuasa NP batteries the most reliable and versatile valve regulated lead acid batteries available With the progress of modern technology and the specific development of application requirements Yuasa has designed generic NP s to be application specific with the introduction of NPC NPH and NPL product ranges NPC is specifically designed to suit the arduous require ments of cyclic applications allowing increased cycle life at least double the cyclic life of conventional types NPH These high performance batteries are specifically designed for applications requiring high rate discharge and offer much improved power densities up to 50 more watts per kilo than conventional NP models when operated
6. 170121 1 B JST SVH 21T P1 1 0 37 0 71 0 768 Bolt fastened terminal G Maximum Permissable Current Amps Faston tab 187 Faston tab 250 Wire Lead 0 5mm BATTERY CAPACITY SELECTION Figure 2 below may be used to determine the minimum battery size expressed in Ampere hours of capacity To determine the required minimum battery capacity plot the required discharge current on the horizontal axis against time The point where the current and time lines intersect on or below the diagonal Ah curve shows the minimum capacity required for the application In practice if the intersection point of the time amp current does not fall exactly on a particular Ah curve the next higher value Ah curve should be used to determine the minimum battery capacity size In addition it is recommended that figure 32 Cyclic Service Life and Figure 33 Float Service Life and if appropriate the constant power calculations in table 5 on page 7 should be consulted prior to final selection Yuasa Battery UK Ltd Battery Selection Chart E Iu LA y 11 7 4 D o 2 2 LAN ps Ya Y du y NA MC 7 D V aw o0 E E
7. CHARGING CURRENT CHARGE VOLTAGE FOR 6V 0 25CA 7 50V 15 0V 5 0V CONSTANT VOLTAGE CHARGING AT 20 C 68 F CHARGE VOLTAGE FOR 12V BATTERY o gt VOLUME CHARGE VOLTAGE FOR 4V BATTERY atm lt BATTERY S X gt e CHARGE VOLTAGE AFTER 100 DISCHARGE AFTER 50 DISCHARGE CHARGING CURRENT 3 4 5 6 9 CHARGING TIME HOURS 16 Constant Current Charging This charging method is not often utilised for valve regulated lead acid batteries but is an effective method for charging a number of series connected batteries at the same time and or as an equalising charge to correct variances in capacity between batteries in a series group Extreme care is required when charging NP batteries Figure 16 CONSTANT CURRENT CHARGING CIRCUIT with a constant current If after the battery has reached a fully charged state the charge is continued at the same rate for an extended period of time severe overcharge may occur resulting in damage to the battery Figure 16 shows a typical constant current charging circuit Figure 17 shows the characteristics of two NP6 12 batteries under continuous overcharge conditions Figure 17 CHARACTERISTICS OF TWO NP6 12 UNDER CONDITIONS OF CONTINUOUS OVERCHARGE OVERCHARGING CURRENT 0 6A 0 1CA AMBIENT TEMPERATURE 25 C 77 F CAPACITY TEST 1 5A to 10 2V EVERY 100 HOURS nz2 CAPACITY AT 3HR DISCHARGE 1
8. 2 Excursions 10 Expectancy 29 Expected 1 21 27 29 Eye 28 Fall 5 23 Falls 25 False 24 Fastened 28 Faston 4 Fibre 1 Final 5 7 8 22 29 Fire 2 28 Float 1 5 7 19 22 23 24 25 27 28 29 Floating 11 Gas 1 29 Gases 27 28 Gels 1 Generate 28 Generated 1 27 29 Gloves 28 Gradient 28 Gradients 28 Grid 8 Grids 1 Handling 28 Harsh 18 Heat 21 23 25 28 Heating 23 Hydrogen 29 IEC 1 Ignitable 28 Immediate 28 Impregnated 28 Incinerate 28 Initial 13 19 22 23 24 Initiate 24 Installations 28 Insulated 28 Insulating 21 Insulator 10 Interconnecting 29 ISO 2 Kills 28 Lead 1 4 5 8 10 13 17 18 19 29 Leakage 1 Life 1 2 5 8 9 10 11 13 18 20 25 27 28 29 Load 7 8 19 21 23 27 28 29 Load Sharing 21 Local 28 Loop 28 Loses 24 Loss 1 27 29 Lost 27 Maintained 27 29 Maintaining 19 29 Maintenance 1 5 28 Maintenance Free 28 Medical 2 28 Modules 20 Monitor 28 Monitoring 24 Multi stage 24 Nickel 26 Non Spillable 1 Oils 28 Organic 28 Orientation 1 Overcharge 17 18 19 25 Overcharging 21 Over Discharge 8 24 29 Oxygen 29 Paint 28 Panels 21 Petrol 28 Polyethylene 28 Polypropylene 28 Quality 2 Rate 2 5 8 9 17 27 29 Rated 2 5 19 24 29 Rates 5 6 8 26 Rating 5 Recharge 1 19 23 Recharged 8 27 Recharging 10 Recombination 1
9. CURRENT B Top Charging Since any battery loses capacity through self discharge it is recommended that prior to putting the battery into service a process called top charging be applied to any battery which has been stored for a long period of time Battery Age Within 6 months after manufacture Within 12 months after manufacture In order to successfully top charge a battery stored for more than 12 months the open circuit voltage must be checked to ensure that it is higher than 2 0 volts per cell B Recovery Charge After Deep Discharge When a battery has been subjected to deep discharge commonly referred to as over discharge the amount of electrical energy which has been discharged can be 1 5 to 2 0 times greater than the rated capacity of the battery Consequently a battery which has been over discharged requires a longer charging period than normal Please note from Figure 28 that as a result of increased internal Excluding conditions in which storage temperatures have been abnormally high top charging is recommended within the following parameters Top Charging Recommendations 4 to 6 hours at constant current of 0 1C Amps or 15 to 20 hours at constant voltage of 2 40 vpc 8 10 hours at constant current of 0 1C Amps 20 to 24 hours at constant voltage of 2 40 vpc Therefore ALWAYS check the open circuit voltage FIRST If the open circuit voltage of the battery is 2 0 vpc or lower please refer to us prior
10. at the 10 minute discharge rate NPL Offers up to double the float service life of the conven tional NP type battery Note these models are available to BS6290pt4 1997 The generic types utilise identical physical designs and characteristics to the standard NP type in all aspects except their specific application advancement This in many cases allows users to upgrade without major redesign TECHNICAL FEAT URES Sealed Construction Electrolyte Suspension System Gas Generation Low Maintenance Operation Operation In Any Orientation Low Pressure Venting System 9 Heavy Duty Grids 9 Cyclic Service Life 9 Float Service Life Yuasa s unique construction and sealing technique ensures that no electrolyte leakage should occur from the terminals or case of any NP battery This feature provides for safe and effective operation of NP batteries in any orientation Yuasa NP batteries are classified as Non Spillable and meet all requirements of the International Air Transport Association I A T A Dangerous Goods Regulations to allow transportation by air All Yuasa NP batteries utilise an electrolyte suspension system consisting of a glass fibre separator material This suspension system helps to achieve maximum service life by fully retaining the electrolyte and preventing its escape from the separator material No silica gels or other contaminents are used
11. however experience has shown that their service life often exceeds 6 years if the NP batteries are operated strictly within specification ELE e Low Self Discharge Long Shelf Life Operating Temperature Range High Recovery Capability Quality Assurance APPLICATIONS At temperatures of between 20 amp 25 the self discharge rate of NP batteries per month is approximately 396 of their rated capacity This low self discharge rate permits storage for up to one year without any appreciable deterioration of battery performance Yuasa NP batteries can be used over a broad range of ambient temperatures allowing considerable flexibility in system design and location Yuasa NP batteries have excellent charge acceptance and recovery capability even after very deep discharge Our U K manufacturing plant now has Quality Assurance Standard BS5750 Part 2 EN2900 ISO 9002 together with the M O D Quality Assurance AQAP 4 A list of some of the more common applications for standby or principal power is given below Alarm Systems Cable Television Communications Equipment Computers Control Equipment Electronic Cash Registers Electronic Test Equipment Emergency Lighting Systems Fire amp Security Systems Geophysical Equipment Marine Equipment Medical Equipment Microprocessor Based Office machines Portable Cine amp Video Lights Power Tools Solar Power
12. is often its greatest at part load When cleaning the battery case ALWAYS use a water dampened cloth but NEVER use oils organic solvents such as petrol paint thinners etc DO NOT even use a cloth that is impregnated or has been in contact with any of these or similar substances Do not attempt to dismantle the battery If accidental skin eye contact is made with the electrolyte wash or bathe the affected area part straight away with liberal amounts of clean fresh water and seek IMMEDIATE medical attention DO NOT INCINERATE batteries as they are liable to rupture if placed into a fire Batteries that have reached the end of their service life can be returned to us for safe disposal Touching electrically conductive parts might result in an electric shock Be sure to wear rubber gloves before inspection or maintenance work The use of mixed batteries with different capacities that may have been subjected to different uses be of differ ent ages and are of different manufacturers is liable to cause damage to the battery itself and or the associated equipment If this is unavoidable please consult us beforehand To obtain maximum life batteries should never be stored in a discharged state In order to obtain maximum working life when the batteries are used in an UPS system the following is advised a Wherethe D C input exceeds 60 volts each bat tery should be insulated from the battery stand by using suitable polypro
13. progresses When charging at 2 275 volts per cell the current at the final stage of charging will drop typically to a value of between 0 0005C Amps and 0 004C Amps The charged volume in ampere hours shown on the vertical axis of Figures 10 15 pages 14 16 indicate the ratio of charged ampere hours to the previously discharged ampere hours When a battery has been charged up to a level of 100 of the discharged ampere hours the electrical energy stored and available for discharge will be 9096 or more of the energy applied during charging Charging voltage should be regulated in relation to the ambient temperature When Figure 25 CHARGING CHARACTERISTICS AT DIFFERENT TEMPERATURES CHARGED 97 VOLUME CHARGING CURRENT CHARGE VOLTAGE FOR 6V BATTERY gt gt x 2 lt cu c e 15 0 1CA 6 825V 13 65V CONSTANT VOLTAGE CHARGING For float standby use For cyclic use 2 275 x 0 005 volts per cell 2 40 to 2 50 volts per cell the temperature is higher the charging voltage should be lower and conversely when the temperature is lower the charging voltage should be higher For specific recommendations please refer to the section on Temperature Compensation on page 25 Similarly charged volume measured in ampere hours realised over a given time will vary in direct relation to the ambient temperature the higher the ambient temperature the higher the charged volume in a given period
14. to attempting to Top Charge resistance the charging current accepted by an over discharged NP battery during the initial stage of charging will be quite small but will increase rapidly over approximately the first 30 minutes until the internal resistance has been overcome then normal full recovery charging characteristics resume Figure 28 CHARGING CHARACTERISTICS OF NP 6 12 AFTER DEEP DISCHARGE CHARGED VOLUME CHARGING CURRENT CHARGE VOLTAGE 58 x gt lt N CHARGING CURRENT 6 0 25 14 5V CONSTANT VOLTAGE CHARGE FOR 24 HOURS DEEP DISCHARGE WITH 2 OHM RESISTOR FOR 24 HOURS AND STORED FOR 30 DAYS IN OPEN CIRCUIT CONDITION AMBIENT TEMPERATURE 25 C 77 F CHARGE VOLTAGE 8 12 14 CHARGING TIME HOURS Because of this initial small charge current in an over discharged battery as described above unless due consideration is given to this fact then if the charging regime uses current monitoring for determining either the state of charge and or for signalling that the switching point has been reached for reducing the voltage to a float standby value as is the normal case in a multi stage charger the charger could be tricked into entering further stages before completing earlier ones In other words the charger may give a false full charge indication or may initiate charge at the float voltage figure instead of at a higher voltage level Temperature Compensation
15. when it is discharged at a value of current that exceeds its 20 Hour discharge rate This should be taken into consideration when a battery is being selected for a particular application Figure 3 DISCHARGE CHARACTERISTIC CURVES AT 25 C 77 F V V Note C Given Capacity as stated on each battery in Ah 12V FOR6V BATTERY BATTERY NP AT 25 C 77 F 13 0 6 5 12 0 6 0 110 5 5 ar gt lt 10 0 5 0 joe 9 0 4 5 8 0 4 0 1 2 4 6 810 20 40 60 2 4 6 810 20 MINUTES HOURS DISCHARGE TIME Table 4 20 Hr Discharge Current Capacity 005 0 08 A 0 16 0 32A 0 48 0 10 0 20 0 40 0 60 0 12 0 24 0 48 0 72 0 21 0 42 0 84 1 26 0 20 0 40 0 80 1 20 0 23 0 46 0 92 1 38 0 28 0 56 1 12 1 68 0 30 0 60 1 20 1 80 0 40 0 80 1 60 2 40 0 60 1 20 2 40 3 60 0 70 1 40 2 80 4 20 0 80 1 60 3 20 4 80 1 00 2 00 4 00 6 00 1 20 2 40 4 80 7 20 1 70 3 40 6 80 10 20 2 40 4 80 9 60 14 40 3 80 7 60 15 20 22 80 6 50 13 00 26 00 39 00 7 8 15 60 31 20 46 80 13 00 26 00 52 00 78 00 Table 5 Watts Ah Cell NP Range 25C Mi d i d Tu 5421 3 884 3 074 2 554 2 211 1 943 1 767 1 621 165 268 3 806 2984 2513 2178 1914 1743 1602 1458 1 194 02713 0 518 0 341 rene sra 2o22 247 ven vos soo om oss oer IE AAA O OE IEA 8 10 3 163 2526 2 144 1 857 1655 1462 1350 1240 1
16. 0 OPEN CIRCUIT VOLTAGE REMAINING CAPACITY 96 The internal resistance impedance of a battery is lowest when the battery is in a fully charged state The internal resistance increases gradually during discharge Figure 8 Figure 8 INTERNAL RESISTANCE OF NP BATTERY shows the internal resistance of an NP6 12 battery measured through a 1 000 Hz AC bridge INTERNAL TERMINAL RESISTANCE VOLTAGE mQ BATTERY NP6 12 AMBIENT TEMPERATURE 25 C 77 F MEASURED WITH 1000Hz AC BRIDGE 560mA 20HR 300mA 8 10 12 14 16 18 20 DISCHARGE TIME HOURS 12 Impedance testing can be performed using the Yuasa YPI 2 Impedance comparator test meter this form of testing is non intrusive and can be performed online with the battery still connected within its system Note The YPI 2 meter can CHARGING Correct charging is one of the most important factors to consider when using valve regulated lead acid batteries Battery performance and service life will be directly affected by the efficiency of the charger selected The basic charging methods are Constant Voltage Charging Constant Current Charging Taper Current Charging Two Stage Constant Voltage Charging not be used where a high AC ripple content exists By using this test method deterioration can be detected with out removing the battery from its standby mode Constant Voltage Charging Charging at constant voltage is the mos
17. 00 200 300 400 500 600 700 800 900 CHARGING TIME HOURS 17 Taper Current Charging This method of charging is not recommended due to the constant current characteristics of taper charging being somewhat harsh on valve regulated lead acid batteries This particular charging regime can often shorten battery service life However because of the simplicity of the circuit and subsequent low cost taper current charging is often used to charge a number of series connected batteries that are subject to cyclic use When using a taper charger it is recommended that the charging time is either limited or that a charging cut off circuit be incorporated to prevent overcharge Please consult us for specific recommendations In a taper current charging circuit the charging current decreases gradually and the charging voltage rises proportionately as the charge progresses When designing a taper charger it should be borne in mind that variations in the mains input supply will be reflected in the output of the charger Figure 18 illustrates the characteristics of a typical taper charger Figure 18 CHARGING CHARACTERISTICS OF A TAPER CHARGER CHARGE VOLTAGE CHARGING CURRENT CHARGE VOLTAGE CHARGING CURRENT CHARGING TIME Figure 19 TAPER CURRENT CHARGING CIRCUITS A HALF WAVE B FULL WAVE C FULL WAVE CENTER TAP Ag Ap _ 18 Two Stage Constant Voltage Charging Two stage constant voltage charging is
18. 023 0 622 0 489 0300 Calculation of battery size required Constant Power load conditions Using Table 5 Watts Cell Ah map the required load time to the specified end of discharge voltage The figure obtained is the Constant Power available from each 1Ah of NP type cell Divide this number into the required wattage load per cell to give the minimum value of capacity required to supply the required load Example 5 3kW load requires 30 minutes standby operating from maximum 272V down to end of discharge 204V at 25 C 1 Recommended float voltage for NP batteries at 25 C is 2 26volts per cell To find the number of series cells required divide the maximum load voltage by 2 26v 272 2 26 120 cells 2 Divide the end voltage by the number of cells to find the value of end volts per cell 204 120 1 7vpc 3 Divide specified load by number of cells to find load in watts per cell 5 300 120 244 17w pc 4 Map end vpc 1 7 against required load time 30 mins in Table 5 1 872watts per cell per Ah 5 Divide load in wpc by value from Table 5 44 17 1 872 23 59Ah 6 Select the battery from the list on page 3 20 x NP24 12 is the minimum requirement Table 6 DISCHARGE CAPACITY AT VARIOUS DISCHARGE RATES Discharge Current Capacity 05 to 1 75V C 0 093CAto 1 75V C 0 17CAto 1 70V C 0 25CA to 1 67V C 0 60CA to 1 55V C B Over Discharge Deep Discharge The dotted line in Figure 3 indicates the lowest condi
19. 29 Recombined 27 Recombines 1 Recover 8 Recovered 19 Recovery 2 24 29 Rectifier 29 Recycling 2 23 Regime 18 24 31 Regulated 1 4 5 13 17 18 19 20 21 22 29 7 Regulation 23 Valve 1 4 5 13 17 18 19 29 Regulations 1 Vibration 28 Reseal 1 Volt 7 20 24 Resin 28 7 23 24 Resistance 8 12 13 24 28 29 Resistive 21 WAC 7 Rubber 28 Wash 28 Rupture 28 Water 1 27 28 Watt 29 Safe 1 20 28 Watts 7 Safest 1 Safety 28 Self 2 9 29 Self Discharge 2 9 24 29 Separator 1 Separators 29 Set 19 23 25 Setting 28 Severe 8 17 Shelf 2 9 10 29 Shock 28 Short 19 20 23 25 Shorten 18 Silica 1 Skin 28 Soaked 28 Solar 2 21 Soldering 28 Solvents 28 Sparks 28 Stage 13 19 22 23 24 29 Stages 24 Stand 28 Standby 1 2 7 19 20 22 23 24 25 27 28 29 Storage 2 9 10 24 Stored 9 10 22 24 28 29 Storing 29 Sulphate 10 Sulphation 8 10 Sunlight 21 Suspension 1 Taper 13 18 Temperature 2 5 9 10 11 22 25 27 28 Temperatures 2 9 10 11 21 22 24 25 26 27 28 Thermally 25 Thinners 28 TIPS 28 Top 5 10 24 Top charging 10 24 Touching 28 Trickle 29 Undercharge 25 Undercharging 23 _ 32 5 Further technical information available on request Transportation of Yuasa Batteries by Air Sea or Road Effect of High Temperature on Battery
20. Float Life Gas Production in Valve Regulated Lead Acid V R L A Batteries Safe Handling of product C O S H H NP Batteries BS6290 Part 4 Shelf Life Self Discharge and Top Charging Pre Installation Battery Checks Recovery of Sulphated Batteries Effects of Altitude on Valve Regulated Lead Acid V R L A Batteries Ventilation Environmental Requirements of NP and UXL Batteries on Float Standby Environmental Safety of NP Batteries Standards Float Service Life of NP Batteries Statement on Service Life Shock and Vibration Tests on NP Batteries Enhanced Performance and Life Through Correct Charging Torque Settings NPL Short Form NPC Short Form NPH Short Form YPI 2 Impedance Comparator Test M eter Date Code Interpretation Product Safety Data Sheet Connector Selection Chart
21. ING AT 20 C 68 F CHARGE VOLTAGE FOR 12V BATTERY CHARGE VOLTAGE FOR 4V BATTERY PS CHARGED of lt co co 6 8 10 12 14 CHARGING TIME HOURS Figure 12 CHARGING CHARACTERISTICS VOLUME CHARGING CURRENT 0 1CA 7 50V 15 0V 5 0V CONSTANT VOLTAGE CHARGING AT 20 C 68 F CHARGE VOLTAGE FOR 12V BATTERY CHARGE VOLTAGE FOR 4V BATTERY 2S CHARGED ose lt CHARGE VOLTAGE AFTER 100 DISCHARGE AFTER 50 DISCHARGE 6 8 10 12 14 CHARGING TIME HOURS Figure 13 CHARGING CHARACTERISTICS CHARGED CHARGING CURRENT 0 25CA 6 825V 13 65V 4 55V CONSTANT VOLTAGE CHARGING AT 20 C 68 F CHARGE VOLTAGE FOR 12V BATTERY CHARGE VOLTAGE FOR 4V BATTERY 9 VOLUME Oo 4 ce Pon lt FOR 6V BATTERY lt pA gt c c gt AFTER 100 DISCHARGE AFTER 50 DISCHARGE 6 8 10 12 14 16 18 20 CHARGING TIME HOURS Figure 14 CHARGING CHARACTERISTICS CHARGED CHARGING CURRENT CHARGE VOLTAGE Z FOR 6V 0 25CA 7 20 14 4V 4 8V CONSTANT VOLTAGE CHARGING AT 20 C 68 F CHARGE VOLTAGE FOR 12V BATTERY CHARGE VOLTAGE FOR 4V BATTERY 9 VOLUME m ee gt 5 BATTERY gt S 5 e CHARGE VOLTAGE AFTER 10096 DISCHARGE AFTER 50 DISCHARGE CHARGING CURRENT 6 8 10 12 14 CHARGING TIME HOURS Figure 15 CHARGING CHARACTERISTICS CHARGED
22. NP batteries incorporate a unique Yuasa design that effectively recombines over 9996 of the gas generated during normal usage During the life of NP batteries there is no need to check their specific gravity or add water etc In fact there are no provisions for such maintenance functions to be carried out The combination of sealed construction and Yuasa s electrolyte suspension system permits operation of NP batteries in any orientation excluding continuous inverted use without loss of capacity electrolyte or service life The NP batteries made in our factory in Wales also conform to BS EN61056 1 1993 and IEC 1056 1 1991 Yuasa NP batteries are equipped with a safe low pressure venting system which is designed to release excess gas and reseal automatically in the event of the internal gas pressure rising to an unacceptable level This low pressure venting system coupled with the significantly high recombination efficiency make Yuasa NP batteries one of the safest valve regulated lead acid batteries available The heavy duty lead calcium alloy grids in NP batteries provide an extra margin of performance and service life in both float and cyclic applications even in conditions of deep discharge Depending upon the average depth of discharge over 1 000 discharge recharge cycles can be expected from NP batteries The expected service life of the standard model NP battery when used in stand by applications is typically 5 years
23. T CHARGING CURRENT AH CHARGING VOLUME 0 17C Amp F V 1 7V CELL 0 09C AMP 125 OF DISCHARGED CAPACITY AMBIENT TEMPERATURE 20 C TO 25 C 68 F TO 77 F 120 g a lt O O lt 2 c LU LU I m 3 lt 2 1000 1200 1400 NUMBER OF CYCLES CYCLES The relationship between the number of cycles which can be expected and the depth of discharge is readily apparent If an extended cycle life is required then it is common practice to select a battery with a larger capacity Float Service Life NP batteries are designed to operate in float standby service for approximately 5 yrs 7 10 yrs NPL based upon a normal service condition in which float charge voltage is maintained between 2 275vpc 0 005 Figure 33 FLOAT SERVICE LIFE STANDARD NP AH 120 PERCENTAGE OF CAPACITY AVAILABLE TESTING CONDITIONS FLOATING VOLTAGE than the one that is required to carry the load Thus at the specified discharge rate over the specified time the depth of discharge will be shallower and cyclic service life will be longer volts per cell in an ambient temperature of approximately 20 C Figure 33 shows the float service life characteristics of NP batteries when discharged once every three months to 100 depth of discharge 2 275VPC 0 005 V CELL AMBIENT TEMPERATURE 20 C TO 22 C 68 F TO 72 F LIFE YEARS In a normal float service where the chargi
24. Therefore consideration Should be given to thermally isolating the battery and temperature sensor from other heat generating components in the system Charging Efficiency The charging efficiency of a battery is expressed by the following formula Ah Ampere hours Discharged Ah Ampere hours Charged The charging efficiency varies depending upon the state of charge of the battery temperatures and charging rates Figure 30 illustrates the concept of the state of charge and charging efficiency As shown in Figure 31 Yuasa NP batteries exhibit very high charging efficiency even at low charging rates unlike some nickel cadmium batteries Figure 31 CHARGING EFFICIENCY CHARGE EFFICIENCY 0 001 0 002 0 005 0 01 Figure 30 CHARGING EFFICIENCY VS STATE OF CHARGE CHARGE EFFICIENCY 50 STATE OF CHARGE 40 C AT 25 C 0 02 CHARGING CURRENT xCA EXPECTED SERVICE LIFE OF NP BATTERIES m Cyclic Service Life There are a number of factors that will affect the length of cyclic service of a battery The most significant are ambient operating temperature discharge rate depth of discharge and the manner in which the battery is recharged Generally speaking the most important factor is depth of discharge Figure 32 illustrates the effects of depth of discharge on cyclic life Figure 32 CYCLE SERVICE LIFE IN RELATION TO DEPTH OF DISCHARGE TESTING CONDITIONS DISCHARGE CURREN
25. a recommended method for charging valve regulated lead acid batteries in a short period of time and then maintaining them in a fully charged float or standby condition Figure 20 illustrates the characteristics of a two stage constant voltage charger Figure 20 CHARGING CHARAGTERISTICS OF A TWO STAGE CONSTANT VOLTAGE CHARGER CHARGE CURRENT CHARGE VOLTAGE CHARGING CURRENT The characteristics shown in Fig 20 are those of a constant voltage current limited charger In the initial charging stage the current flowing into the battery is limited to a value of 0 25C Amps The charging voltage across the battery terminals rises during the charging process to a value equal to the constant voltage output of the charger which is set to 2 45 volts per cell Whilst continuing to charge in stage 1 A B at 2 45 volts per cell the current will eventually decrease to point Y where the value of this decreasing current is sensed causing the circuit to CHARGE VOLTAGE Y SWITCHING POINT NOTE Current can drop to as low as 0 002C Amps CHARGING TIME Figure 21 EXAMPLE OF A TWO STAGE CONSTANT VOLTAGE CURRENT LIMITED CHARGING CIRCUIT lt gt KE gt KD C gt When this charging method is used the output values will be as follows Initial Charge Current Charge Voltage Ist Stage 2 45v cell 2 40 to 2 50 v cell max 2nd Stage 2 2 vpc 0 005 0 25C Amps max _ 19 Switch int
26. cities 28 29 Capacity 1 2 3 5 7 8 9 12 17 19 21 24 27 29 Care 17 Cell 5 7 11 13 19 22 23 24 25 27 29 Cells 7 21 Charge 2 8 10 17 18 19 23 24 26 27 29 Charged 12 13 17 19 21 22 23 26 29 Charger 13 18 19 20 23 24 25 29 Chargers 13 21 Charging 10 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Chemical 29 Classified 1 Clean 28 Cleaning 28 Cloth 28 Combine 1 Compensate 29 Compensated 25 Compensation 22 25 28 Conductive 28 Confined 28 Constant 5 7 13 17 18 19 20 21 22 23 24 29 Contact 28 Contaminants 1 Control 2 21 Controlled 13 Cool 10 Cooling 28 Corrosion 27 Corrosive 27 Cycles 1 27 29 Cyclic 1 5 18 20 22 25 27 28 29 Damage 8 17 23 28 Damaged 8 Dampened 28 Dangerous 1 Deep 1 2 8 24 29 Demand energy 21 Density 1 29 Depth 1 12 27 29 Deterioration 2 Detrimental 10 Discharge 1 2 5 6 7 8 9 12 22 24 27 29 Discharged 5 8 22 23 24 26 27 28 29 Discharges 28 Discharging 29 Dismantle 28 Disposal 28 Dry 10 Drying 27 Efficiency 1 7 13 26 Efficient 1 19 28 Electrochemical 25 28 Electrodes 27 Electrolyte 1 27 28 29 Emergency 2 EN 2 Enclosure 21 28 Enclosures 21 End 5 7 27 28 Energy 1 21 22 24 28 29 Environmental 21 Equalisation 28 Equalising 17 Exceeds 1 5 21 28 Excellent
27. ed Systems Telecommunication Systems Television amp Video Recorders Toys Uninterruptible Power Supplies Vending Machines YUASA NP BATTERY CONSTRUCTION Terminals Relief Valve Top Cover Sealant Negative Plate Electrolyte Positive Plate Container m 2 r U ri Q 5 Nominal Nominal Voltage Capacity Ah Weight Height over Approx 20Hr 10Hr L mm W mm Terminals mm Kg Layout Terminals NON 53 Dimensions NP4 2 4H NP10 4 NP1 6 NP1 2 6 NP2 8 6 NP3 6 ue wes me s was 5 mezes 5 ws s Mme oe ws os 25 1 lt pasos 6 xo ws wem gt e ow 5 as os w 2 x am s os gt A wmm x 20 3 150 m om mx s 1 a om s om ese a m m o We e kx x wm om ims 1 wm Table 2 LAYOUT 185 124 098 059 031 020 004 031 Faston tab 187 A Faston tab 187 079 004 INCH Z MM 472 12 00 453 11 50 433 11 00 216 5 50 079 2 00 59 01 310 1 008 Bolt fastened terminal F WIRE AWG 20 UL 1007 JST No VHR 2N 18011015 eee TERMINAL BLUE TERMINAL AMP NO
28. f current limiting and heat sensing circuits fitted within the charger are normally sufficient for the purpose B Charge Output Regulation and Accuracy To ensure the correct voltage is set accurately when adjusting the output voltage of a constant voltage charger all adjustments must be made with the charger ON LOAD Adjusting the output voltage with the charger in an OFF LOAD condition may result in undercharging The constant voltage range required by a battery is always defined as the voltage range applied to a battery which is fully charged Therefore a charger having the output characteristics illustrated in Figure 27 should be adjusted Figure 27 OUTPUT VOLTAGE ADJUSTMENT CHARGING CHARACTERISTICS CHARGING CURRENT CHARGING TIME 223 Figure 26 CONSTANT VOLTAGE CHARGE CHARACTERISTICS WITH NO CURRENT LIMIT CHARGE VOLTAGE 2 30V C TEMPERATURE 25 C 77 F CHARGING CURRENT 024 6 8 10 20 30 40 50 60 CHARGING TIME SECONDS with the output voltage based on point A The most important factor in adjusting charger output voltage is the accuracy at point A which should be in the range of 2 215vpc 0 005 volts per cell however this accuracy is not normally required over the entire range of the load A charger adjusted in accordance with Figure 27 will never damage a battery even if the charger has the characteristics shown by the broken line in Figure 27 OUTPUT CHARACTERISTICS OUTPUT VOLTAGE OUTPUT
29. he longest service life will be attained where the battery temperature does not exceed 20 C also see notes 3 amp 8 hereunder When calculating the correct float voltage setting whether or not temperature compensation is required full consideration must be given to the temperature of the battery and room ambient For the purpose of the calculation consider the temperature of a battery on float to be 1 C above local ambient Also if the battery is used in an enclosure the temperature gradient of the enclosure itself must be included in the calculation i e The operating temperature of the battery is given by Room temperature enclosure temperature 1 Since a battery may generate ignitable gases do not install close to any equipment that can produce electrical discharges in the form of sparks When the battery is operated in a confined space adequate ventilation should be provided The battery case is manufactured from high impact ABS plastic resin It should not be placed in an atmosphere of or in contact with organic solvents or adhesive materials Correct terminals should be used on battery connecting wires Soldering is not recommended but if unavoidable please refer to us for further guidance Avoid operating at temperatures outside the range 15 to 50 C for float standby applications and to 35 C for cyclic use When there is a possibility of the battery being subjected to heavy vibration or mechanica
30. l shock it should be fastened securely and the use of shock absorbent material is advisable When connecting the batteries free air space must be provided between each battery The recommended minimum space between batteries is 0 2 inches 5mm to 0 4 inches 10mm In all installations due consideration must be given to adequate ventilation for the purposes of cooling When the batteries are to be assembled in series to provide more than 100V proper handling and safety procedures must be observed to prevent accidental electric shock see note 15 below If 2 or more battery groups are to be used connected in parallel they must be connected to the load through 11 12 13 14 15 16 17 18 _ 28 lengths of wires cables or busbars that have the same loop line resistance as each other This makes sure that each parallel bank of batteries presents the same impedance to the load as any other of the parallel banks thereby ensuring correct equalisation of the source to allow for maximum energy transfer to the load Ripple current the AC component on the DC charge cur rent Ideally this should be zero as it will reduce the service life of a cell battery the larger the component the greater the reduction it will cause For example 0 1C Amps R M S will reduce the optimum service life by a minimum 396 Note 1 Ripple current can be source or load generated Ripple current can vary with load change and
31. mentary charging 27 Standby Service General term for an application in which the battery is maintained in a fully charged condition by trickle or float charging Synonymous with Float Service 28 Trickle Charge Continuous charging by means of a small current designed to compensate for self discharge in a battery which is isolated from any load For valve regulated lead acid batteries constant voltage charging is common 29 Charged Volume The power returned to the battery by charging as a percentage of the power taken out during discharge 30 VPC Term for volts per cell E amp O E Abnormal 23 Abnormally 8 24 ABS 28 Absorbed 29 Absorbent 28 Accelerated 27 Accept 8 23 Acceptance 2 10 23 Accepted 24 Accidental 28 Accuracy 23 Accurately 23 Acid 1 4 5 8 10 13 17 18 19 29 Activity 25 Adequate 21 28 Adhesive 28 Adjusted 23 Adjusting 23 Adjustment 23 Adjustments 23 Adverse 10 Advisable 28 Advised 21 28 Age 24 Ages 28 Air 1 28 Alarm 2 28 Allow 28 Alloy 8 Ambient 2 5 9 10 11 22 25 27 28 Ampere 5 29 Amperes 29 Ampere hours 5 22 26 29 Apparent 27 AQAP 2 Atmosphere 28 Autonomy 7 Avoid 25 28 Bank 28 Banks 28 Bathe 28 Bloc 7 Block 20 21 Bloc s 7 BS 1 2 Busbars 28 Cable 2 Cables 28 Cadmium 26 Calcium 8 Calcium alloy 1 8 Capa
32. ng control devices of any kind Naturally in cases where the output of the solar array exceeds the capacity of the battery and weather Figure 24 BLOCK DIAGRAM OF A SOLAR POWERED CHARGING SYSTEM SOLAR CELL or PANEL LOAD conditions are such that the potential for overcharging the battery exists appropriate regulated charging circuitry between the solar panels and the battery is recommended Remote sites and other outdoor applications is where most solar powered systems are to be normally found When designing a solar powered system for this class of application a great deal of consideration must be given to environmental conditions For example enclosures which may be used to house batteries and other equipment may be subject to extremely high internal temperatures when exposed to direct sunlight Under such conditions insulating the enclosure and or treating the surface of the enclosure with a highly reflective heat resistive material is highly recommended In general when designing a solar powered system consultation with the manufacturers of both the solar panel and the battery is strongly advised 21 B Charging Voltage The charging voltage should be chosen according to the type of service in which the battery will be used Generally the following voltages are used In a constant voltage charging system a large amount of current will flow during the initial stage of charging but will decrease as the charging
33. ng voltage is maintained at 2 275vpc 0 005 volts per cell See Fig 34 the gases generated inside an NP battery are continually recombined into the negative plates and return to the water content of the electrolyte Therefore electrical capacity is effectively not lost due to the drying up of the electrolyte the loss of capacity and eventual end of service life is brought about by the gradual corrosion of the Figure 34 RELATIONSHIP BETWEEN FLOAT CHARGE VOLTAGE AND BATTERY LIFE 20 C 100 75 o 4 gt cc lt ea 3 N OVER CHARGE gt UNDER CHARGE pr 2 1 2 3 2 2 2 4 FLOAT CHARGE VOLTAGE V CELL 27 electrodes It should be noted that this corrosive process will be accelerated by high ambient operating temperatures and or high charging voltage When designing a float service system always consider the following LENGTH OF SERVICE LIFE WILL BE DIRECTLY AFFECTED BY THE NUMBER OF DISCHARGE CYCLES DEPTH OF DISCHARGE AMBIENT TEMPERATURE AND CHARGING VOLTAGE DESIGN APPLICATION TIPS TO ENSURE MAXIMUM SERVICE Yuasa NP batteries are highly efficient maintenance free electrochemical systems designed to provide years of trouble free electrical energy The performance and service life of these batteries can be maximised by observing the following guidelines 1 10 Heat kills batteries Avoid placing batteries in close proximity to heat sources of any kind T
34. o the second stage B C reducing the charging voltage from 2 45 volts per cell to a constant voltage float standby level of 2 3 volts per cell The switch to stage two where the constant voltage level of 2 3 volts per cell is applied occurs after the battery has recovered about 80 of its rated capacity This is one of the most efficient charging methods available as the recharge time is minimised during the initial stage whilst the battery is protected from overcharge by the system switching to stage 2 float standby charge at the switching point Y Switching Current From Ist Stage to 2nd Stage 0 05C Amps 0 04C to 0 08C Amps Note This charging method cannot be used in applica tions where the load and the battery are connected in parallel m YUASA C V C C CONSTANT VOLTAGE CONSTANT CURRENT CHARGE MODULE The Yuasa C V C C is a fully regulated automatic charging module designed for NP batteries There are two 6 volt versions available one for standby applications and the other for cyclic applications Also there are two 12 volt versions available again one for standby applications and the other for cyclic applications When interfaced with the appropriate AC or DC power supply the Yuasa C V C C guarantees safe charging and maximum battery life Figure 23 is a block diagram of the C V C C Figure 23 BLOCK DIAGRAM OF C V C C YUASA C V C C CHARGE UNIT WHITE WHITE BLUE GREEN BLUE YELLOW BLACK RED
35. of time and the lower the ambient temperature the lower the charged volume in the same given period of time Figure 25 shows the relationship between charged volume and temperature CHARGE VOLTAGE FOR 12V BATTERY CO 20 C 68 F AT 40 C 104 F CHARGING CURRENT 20 25 30 CHARGING TIME HOURS 22 Initial Charge Current Limit A discharged battery will accept a high charging current at the initial stage of charging High charging current can cause abnormal internal heating which may damage the battery Therefore when applying a suitable voltage to recharge a battery that is being used in a recycling application it is necessary to limit the charging current to a value of 0 25C Amps However in float standby use Yuasa NP batteries are designed so that even if the available charging current is higher than the recommended limit they will not accept more than 2C Amps and the charging current will fall to a relatively small value in a very brief period of time Normally therefore in the majority of float standby applications no current limit is required Figure 26 shows current acceptance in NP batteries charged at a constant voltage of 2 30 vpc without current limit When designing a charger it is recommended that suitable circuitry is employed to prevent damage to the charger caused by short circuiting the charger output or connecting it in reverse polarity to the battery The use o
36. pylene or polyethylene material In high voltage systems the resistance between battery and stand should always be greater than 1 An appropriate alarm circuit could be incorporated to monitor any current flow b GLOSSARY 1 Ampere A The unit for measuring the flow of electric current 2 Ampere hour The current in A amperes multiplied by time in hours Used to indicate the capacity of a battery 3 Capacity C Ampere hours that can be discharged from a battery Lu TM The minimum unit of which a battery is composed consisting of positive and negative plates separators electrolyte etc In valve regulated lead acid batteries the nominal voltage is 2 volts per cell gt Charging The process of storing electrical energy in a battery in chemical form 6 Cyclic Service The use of a battery with alternative repetition of charging and discharging 7 Cycle Service Life The total number of cycles expected at a given depth of discharge 8 Deep Discharge a Discharge of a battery until 10096 of the capacity is exhausted dana b Discharge of a battery until the voltage under load drops below the specified final discharge voltage Over discharge 9 Depth of Discharge The ratio of discharge capacity vs the rated capacity of a battery 10 Discharge The process of drawing sto
37. red energy out of a battery in the form of electrical power 11 Energy Density The ratio of energy that can be discharged from a battery to the volume of that battery measured in Watt Hours WH per cubic inch or litre 12 Float Method of use in which the battery and the load are connected in parallel to a float charger or rectifier so the constant voltage is applied to the battery continuously maintaining the battery in a fully charged state and to supply power to the load from the battery without interruption or load variation 13 Gas Recombination The process by which oxygen gas generated from the positive plates during the final stage of charging is absorbed into the negative plates reducing the potential at the negative plates so repressing the generation of hydrogen 14 Impedance The ratio of voltage variation vs current variation in alternating a c supply 15 Internal Resistance The term given to the resistance inside a battery consisting of the sum of resistance of the electrolyte the positive and negative plates amp separators etc 16 Life Expectancy Expected service life of a battery expressed in total cycles or time in float service in relation to a specified application 17 Nominal Capacity The nominal value of rated capacity In valve regulated lead acid batteries nominal capacity is usually measured at the 20 ho
38. s in battery increases and conversely at lower temperatures relation to battery capacity the electrical Ah capacity of a battery decreases Figure 4 TEMPERATURE EFFECTS IN RELATION TO BATTERY CAPACITY 76 120 PERCENTAGE OF CAPACITY AVAILABLE TEMPERATURE STORAGE SELF DISCHARGE and SHELF LIFE B Self Discharge The self discharge rate of NP batteries is approximately ambient storage temperature Figure 5 shows the 3 per month when stored at an ambient temperature of relationship between storage times at various 20 C The self discharge rate will vary as a function of temperatures and the remaining capacity Figure 5 SELF DISCHARGE CHARACTERISTICS 100 gt lt lt o 2 2 lt a STORAGE TIME MONTHS Shelf Life In general when lead acid batteries of any type are stored for extended periods of time lead sulphate is formed on the negative plates of the batteries This phenomenon is referred to as sulphation Since the lead sulphate acts as an insulator it has a direct detrimental effect on charge acceptance The more advanced the sulphation the lower the charge acceptance Table 8 below shows the normal storage time or shelf life at various ambient temperatures Table 8 Shelf Life at Various Temperatures 0 C 32 F to 20 C 68 F Shelf Life 12 months 9 months 5 months 2 5 months 21 C 70 C to 30 C 86 F 31 C 88 F to 40 C 104 F
39. t suitable and commonly used method for charging valve regulated lead acid batteries Figures 10 15 show the charging characteristics of NP batteries when charged by constant voltage chargers at 2 275 volts cell 2 40 volts cell and 2 50 volts cell when the initial charging current is controlled at 0 1C Amps and 0 25C Amps Figure 9 shows one example of a constant voltage charging circuit In this circuit the initial charging current is limited by the series resistance R1 Figure 9 ONE EXAMPLE OF CONSTANT VOLTAGE CHARGING CIRCUIT Note The recommended float charge voltage for NP type batteries at 20 C is 2 275vpc 0 005v this should be the measured average for the total battery however when measured within a battery network or string the allowable tolerances can be expected between 2 25vpc and 2 3vpc Batt LOAD 1 Figure 10 CHARGING CHARACTERISTICS CHARGED CHARGING CURRENT CHARGE VOLTAGE 0 1CA 6 825V 13 65V 4 55V CONSTANT VOLTAGE CHARGING AT 20 C 68 F FOR 12V BATTERY FOR 4V BATTERY 9 VOLUME 30 gt FOR 6V BATTERY gt S CHARGE VOLTAGE Qo CHARGE 7 00 VOLTAG E AFTER 100 DISCHARGE AFTER 50 DISCHARGE gt j CHARGE VOLTAGE gt gt e gt CHARGING CURRENT 15 20 25 30 35 CHARGING TIME HOURS Figure 11 CHARGING CHARACTERISTICS VOLUME 0 1CA 7 20V 14 4V 4 8V CONSTANT VOLTAGE CHARG
40. tions for a long period of time severe sulphation recommended voltage under load or cut off voltage for would occur raising the internal resistance of the battery NP batteries at various discharge rates In general lead abnormally high In such an extreme case the battery acid batteries are damaged in terms of capacity and may not accept charge NP batteries have been designed service life if discharged below the recommended cut off to withstand some levels of over discharge However voltages It is generally recognised that all lead calcium whilst this is not the recommended way of operation alloy grid batteries are subjectto over discharge damage Yuasa NP batteries can recover their capacity when For example if a lead acid battery were discharged to recharged correctly Final discharge voltage is shown in zero volts and left standing in either on or off load Table 7 Table 7 FINAL DISCHARGE VOLTAGE Discharge Current Final Discharge Voltage V Cell 0 1C or below or intermittent discharge 1 75 0 17C or current close to it 1 70 0 26C or current close to it 1 67 0 6C or current close to it 1 60 Current in excess of 3C 1 30 For intermediate values see figure 3 on page 6 see figure 3 on page 6 If a battery is to be discharged at a rate in excess of 3C Amps please contact us prior to use B Temperature Characteristics At higher temperatures the electrical Ah capacity of a Figure 4 shows the effects of different temperature
41. ur rate although higher rate discharge types have their nominal capacities given at the 10 hour rate 18 Nominal Voltage The nominal value of rated voltage In lead batteries nominal voltage is 2 volts per cell 19 Open circuit Volts The voltage of a battery which is isolated electrically from any external circuit i e the voltage is measured in a no load condition 20 Parallel Connection Connection of a group of batteries by interconnecting all terminals of the same polarity thereby increasing the capacity of the battery group but not increasing voltage 21 Recovery Charge The process of charging a discharged battery to restore its capacity in preparation for subsequent discharge 22 5 The word Sealed is used as a relative term when referring to cells in NP batteries compared with open vented free electrolyte types 23 Self Discharge Loss of capacity without external current drain 24 Series Connection Connection of a group of batteries by sequentially interconnecting the terminals of opposite polarity thereby increasing the voltage of a battery group but not increasing capacity 25 Shallow Discharge Discharge of a battery in which discharge is less than 5096 depth of discharge D O D 26 Shelf Life The maximum period of time a battery can be stored under specified conditions without needing supple
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