Valve Regulated Pocket Plate Nickel Cadmium Battery. Technical Manual

Transcription

1 Valve Regulated Pocket Plate Nickel Cadmium Battery Technical Manual

2 Contents Pages 1.0. Introduction to VRPP battery 2.0. VRPP - Solution to varied applications 3.0. xygen recombination cycle - A technological innovation 4.0. Battery sizing principles 5.0. Constructional features of the VRPP battery 5.1 Plate construction 5.2 Separator 5.3 Electrolyte 5.4 Terminal current carriers 5.5 Venting system 5.6 Cell container 6.0. Advantages of the VRPP battery 7.0. Characteristics of VRPP battery 7.1 Capacity and nominal voltage 7.2 Internal resistance 7.3 Effect of temperature on performance 7.4 Short circuit values 7.5 Loss due to self discharge 7.6 Cycling 7.7 Water consumption 7.8 Gas evolution 8.0. Battery charging 8.1 Charging methods 8.2 Charge acceptance 8.3 Commissioning requirements 9.0. Special operating factors 9.1 Electrical abuse 9.2 Mechanical abuse Installation and storage 10.1 Emplacement 10.2 Ventilation 10.3 Storage Maintenance of VRPP batteries in service Refurbishment of VRPP batteries VRPP range Cell performance data in amperes at end voltage 1.00V/cell Cell performance data in amperes at end voltage 1.05V/cell Cell performance data in amperes at end voltage 1.10V/cell Cell performance data in amperes at end voltage 1.14V/cell Cell performance data in watts at end voltage 1.00V/cell Cell performance data in watts at end voltage 1.05V/cell Cell performance data in watts at end voltage 1.10V/cell Cell performance data in watts at end voltage 1.14V/cell Battery arrangement - Racks

3 1.0 Introduction to VRPP battery Nickel Cadmium battery continues to be most reliable battery systems available as a source of DC power. Its advantageous features enables it to be most preferred battery systems. With the advent of valve regulated lead acid battery, a new concept was available, a battery that did not require water replenishment. HBL NIFE on this concept developed the VRPP recombination nickel cadmium pocket plate battery. 2.0 VRPP - Solution to varied applications VRPP batteries are designed to meet the needs of applications requiring the traditional high reliability of nickel- cadmium pocket plate cells without the need to top-up with water. They are indeed the best solution for installations, whether they are UPS systems, emergency lighting systems, telecommunications, where the risk of failure of the system is unacceptable. VRPP batteries are also eminently suitable for remote applications such as photovoltaic systems, offshore applications and switching substations, where the system must have total reliability without the need for battery maintenance. Emergency lighting Railway signaling Switchgear Telecommunications Fire and Security systems UPS ffshore oil and gas Photovoltaics Process control Mass transit 3.0 xygen recombination cycle - A technological innovation In a conventional pocket plate nickel cadmium flooded electrolyte battery, water is lost from the battery on o v e r c h a r g e d u e t o t h e f o l l o w i n g r e a c t i o n s : At cathode (negative) 4H + 4e 2 2H 2 + 4H (Hydrogen evolution) At anode (positive) _ 4H _ 2 + 2H2 + 4e (xygen evolution) This corresponds to a theoretical loss of 36 g of water for Ah of overcharge ie., cc per Ah. Hence a conventional cell requires periodic addition of water. The frequency of this operation depends upon the cumulative amount of charge received and the operating temperature. During charging process evolution of xygen begins just before the positive plate is fully charged state and then becomes the main reaction when the fully charged condition is reached. The cadmium negative plate has a better charge acceptance than the positive plate. Hydrogen is not evolved until the plate is virtually fully charged. The VRPP battery has been designed with an excess of Cadmium active material to enhance this effect and ensure that oxygen commences prior to the hydrogen evolution. The oxygen which is produced at the positive plate surface is collected by the special porous separator and thus not allowed to escape from the region between the plates. Some displacement of electrolyte within the separator occurs, thus generating extra unfilled pores for the diffusion of xygen directly to the adjacent cadmium negative plate. 1

4 When xygen reaches the negative plate it reacts either chemically: 2Cd + +2H 2Cd (H) R electrochemically 2 + 2H 2 + 4e 4H...2 Reaction 1 has the effect of chemically discharging some of the cadmium to cadmium hydroxide. The current passing through the battery is used to recharge this material. Reaction 2 consumes the current directly. Thus the hydrogen evolution at the negative plate is suppressed because the preferred reaction is oxygen recombination. The total process of oxygen generation and consumption is referred to as an oxygen recombination cycle. The efficiency of this oxygen recombination process depends upon the relationship between the rate at which oxygen is produced and the rate at which it can be collected and transferred to the negative plate surface. The rate of collection and transfer of oxygen is controlled by the separator type and the cell design. The rate at which oxygen is produced on overcharge is directly related to the charge current once the positive plate has reached a full state of charge. The charge current in turn is controlled by the charging voltage level set on the charging equipment and the ambient temperature. By controlling the charge voltage high efficiencies can be obtained and in this way the rate of water loss can be reduced to a fraction of that from conventional batteries. Though the efficiency of this oxygen recombination is high it will never achieve 100% as small quantities of oxygen will escape from the separator before reaching and reacting at the negative plate. Thus a small quantity of hydrogen will ultimately be generated and hence a low rate of water loss will occur. The battery is designed to accommodate this by provision of a generous electrolyte reserve both above and around each cell pack within the battery. This ensures a long service life without the need to top-up with water. The VRPP battery is fitted with a low pressure vent on each cell, on overcharge the cell have an internal pressure above atmospheric pressure. This vent provides an outlet for the release of small quantities of hydrogen and non combined oxygen and thus controls the internal pressure. If the pressure falls below the release pressure, the vent reseals to prevent air entering inside the cells and minimizes self-discharge reactions. 4.0 Battery sizing Battery sizing principles VRPP is designed to impart an comfortable acquisition for the consumer, based on the performance data generated after the cell kept on float for several months Thus in a situation at normal ambient temperature without any specific requirement with regard to recharge time the published data can be used directly to size the battery. However, if there are requirements with regard to recharge time or temperature then this will modify the result. Examples A standby system is to be sited in a building with an ambient temperature of 20 C and the temperature will always lie between 10 C and 30 C. It has a maximum voltage of 54 V and a minimum voltage of 42 V and requires a back-up of 48 A for 3 hours. In this case a simple 1.42 V/cell single level charger without temperature compensation can be used. Number of cells = 54/1.42 = 38 and the final voltage will be 42/38 = 1. V/cell. The Cell performance data shows that the VRPP gives 50.2 A for 3 hours to 1.10 V/cell and so the battery should be 38 cells of VRPP. At this single level voltage and at this temperature the battery would give 20 years without topping-up. 2

5 However, if for this example there was a restriction that the battery must give 90% of its performance after 10 hours from a totally discharged state then certain modifications need to be made to the calculation. If the single level 1.42 V/cell charger is retained, then from the graph 4 it can be seen that after 10 hours about 75% of the capacity is available and so the battery size will have to be increased by the factor 90/75 or, in other words, 20%. Thus for a current of 57.6 A (48 A + 20 %) to 1.10 V/cell the battery required is 38 cells of VRPP as this gives 59.2 A to 1.10V/cell. This battery will still give the 20 years without topping-up. From the graph 4, it can be seen that a voltage of 1.45 V/cell gives 80% of the capacity after 10 hours is need to increase the cell capacity to compensate for the charge. 90/80 ie., 12.5%, a current of 54 A (48 A %). However, the battery has to be recalculated as, with the same voltage window, the higher charge voltage will modify the end of discharge voltage. Thus, the number of cells = 54/1.45 = 37 and so the end of discharge voltage becomes 42/37 = 1. V. The VRPP performance table gives VRPP, which can discharge a current of 55.2 A to 1.14 V/cell. Hence, in this case the battery is 37 VRPP. The disadvantage of this solution is that a single level charge of 1.45 V/cell will only give 10 years without maintenance and so to achieve the 20 year maintenance level a two stage charger is required. 5.0 Construction features of VRPP battery The construction of VRPP is based on conventional pocket plate technology by introducing special features to enhance the low water consumption, by means of recombination cycle. 5.1 Plate Construction The Nickel Cadmium cell consist of two groups of plates, one containing Nickel Hydroxide (the positive plate) and other containing Cadmium Hydroxide (the negative plate). The active material of pocket plate are retained in pockets formed from double perforated nickel-plated steel strips. These pockets are mechanically linked together, cut to the size corresponding to the plate width and compressed to the final plate dimension. This process leads to a component which is not only mechanically robust but also retains its active material within a steel boundary which promotes conductivity and minimizes electrode swelling. These plates are then welded to a current carrying busbar which further ensures the mechanical and electrical stability of the product. The alkaline electrolyte does not react with steel, which means that the supporting structure of the VRPP battery stays intact and unchanged for the life of the battery. There is no corrosion and no risk of sudden death. 3

6 5.2 Separator The separator is an important feature of the VRPP battery. It is a poly-propylene fibrous material. Using this separator and plastic spacing ribs, the distance between the plates is carefully controlled to give the necessary gas retention to provide the level of recombination required. By providing a large spacing between the positive and negative plates and a generous quantity of electrolyte between plates, the possibility of thermal runaway is eliminated. Valve regulated vent (Low pressure, flame arresting) Nickel coated terminal pillar (Provides good electrical conductivity) Special polypropylene fibrous separator (facilitates recombination) Positive plate (Double perforated steel strip with positive active material) Polypropylene cell container (Fusion welded to lids, makes the cell mechanically sturdy and facilitates visual electrolyte level inspection) Negative plate (Double perforated steel strip with negative active material) VRPP battery is available in both welded (shown here) and bolted construction. 5.3 Electrolyte The electrolyte used in VRPP battery is a solution of Potassium Hydroxide and Lithium Hydroxide to give the best performance and life over a wide range of temperature. The electrolyte concentration is such that it allow the cell to be operated down to -20 deg.c, and it is not necessary to change the electrolyte during the life of the cell It is an important consideration of VRPP, and indeed of all nickel-cadmium batteries, that the electrolyte concentration does not change during charge and discharge. It retains its ability to transfer ions between the cell plates irrespective of the charge level. 5.4 Terminal current carriers The Nickel plated terminals are connected to plates by nut and bolt / welded construction. 4

7 5.5 Venting system VRPP battery is having a unique venting system. The vent releases the Hydrogen and non combined xygen, when the internal pressure increases more than 0.2 bar. If the internal pressure is less, the system reseals to prevent the air entering inside the cell. A flame arresting porous disc is incorporated in the venting system to prevent the possibility of any external ignitions spreading into the VRPP cell. 5.6 Cell container VRPP cells are available in polypropylene containers. The polypropylene container can withstand mechanical stress, shocks and vibrations. It performs in extreme temperature without losing strength, insulating well and resists corrosion. The translucent nature of polypropylene allows visual check of electrolyte. If electrolyte level is less than the minimum indication level, there is a provision to adjust it. 6.0 Advantages of the VRPP battery Long life Reliable and predictable performance Resistant to abuse, electrical and mechanical Zero or low maintenance No sudden death failure due to internal corrosion Wide operating temperature range Low installation costs Negligible gassing - gassing under normal charging conditions is minimal making it safe for installation in human environments such as offices and hospitals 5

8 7.0 Characteristics of VRPP battery 7.1 Capacity and nominal voltage The rated capacity C of a cell is the capacity in ampere hours (Ah) available at 5 hr discharge rate to Volt/cell in accordance with IEC and standard nominal voltage is 1.2 Volt/cell. In practice VRPP c e l l s a r e u s e d i n f l o a t a p p l i c a t i o n s 7.2 Internal resistance The internal resistance of the cell varies with the type of service and state of charge and is therefore, difficult to define and measure accurately. The most practical value for normal application is the discharge voltage response to a change in discharge current. The internal resistance per 1/C of a VRPP cell at room 5 temperature when measured after float charging at normal temperature is 80 milliohms for VRPP 8 to VRPP 50 and 100 milliohms to VRPP 55 to VRPP 744. These figures are for a fully charged cell. For lower s t a t e s o f c h a r g e t h e v a l u e i n c r e a s e. For cells 50% discharged, the internal resistance is about 20% higher and when the cells with 90% discharged condition, the internal resistance is about 80% higher. The internal resistance of fully d i s c h a r g e d c e l l h a s v e r y l i t t l e r e l e v a n c e. 7.3 Effect of temperature on performance Variation of cell performance with the temperature are considered in sizing a battery. Low temperature operation gives a low performance due to the decrease in conductivity of the electrolyte at low temperature. The normal recommended operating temperature range is 0 deg. to 40 deg. C. Performance variation in VRPP cells with temperature Derating factor Hour rate 30 Minute rate 1 Minute rate Temperature: Deg. C Graph 1 6

9 7.4 Short-circuit values The typical short-circuit value in amperes for an VRPP cell is approximately 15 times the ampere-hour capacity. The VRPP battery is designed to withstand a short-circuit current of this magnitude for many minutes without damage. 7.5 Loss due to self discharge The state of charge of VRPP cells on open circuit slowly decreases with time due to self-discharge. This decrease is relatively rapid during the first two weeks but then stabilizes to about 2-3% per month at 20 deg.c. The self-discharge characteristics of a nickel-cadmium cell are affected by the temperature. At low temperatures the charge retention is better than at normal temperature and so the open circuit loss is reduced. However, the self-dischrage is significantly increased at higher temperatures. The open circuit loss for VRPP for the standard temperature and the extremes of the normal operating range is shown in the graph 2. It is necessary to recharge the VRPP cells each year. Typical open circuit loss variation with time Percentage of initial capacity (%) C 0C 20 C pen circuit period (days) Graph 2 7

10 7.6 Cycling VRPP is a low maintenance battery used in standby application and not in continuously cycling applications. The battery is designed using conventional pocket plate electrode technology. Therefore it retains the cycling capability of the parent product. The cycling operation requiring deep discharges and fast recharges involves significant gas evolution and ultra low maintenance properties of the product will be severely reduced. 7.7 Water consumption The VRPP battery works on the xygen recombination principle and therefore has a much reduced water consumption. The level of recombination of these cells are 85-95%. Normal vented type cells will have only 30-35% recombination efficiency. At suitable charging voltages and temperature the VRPP cell will not need water topping for a longer time when compared to the conventional vented type Nickel Cadmium Pocket Plate batteries. 7.8 Gas evolution The gas evolution is a function of the amount of water electrolyzed into hydrogen and oxygen which is not involved in the recombination cycle. The electrolysis of 1 cc of water produces about 2000 cc of gas mixture and this gas mixture is in the proportion of 2/3 hydrogen and 1/3 oxygen. Thus the electrolysis of 1 cc of water produces about 1300 cc of hydrogen. As stated in the previous paragraph, under normal recommended float conditions VRPP has a recombination level of 85% to 95% and so the amount of water which is electrolyzed into gas is small. Typically an VRPP cell will electrolyze about cc of water per Ah of cell capacity per day. This value will be smaller or larger depending on the float voltage value. Thus a typical value of gas emission would be 3.5 cc per Ah of cell capacity per day, or 2.5 cc of hydrogen per Ah of cell capacity per day. Effect of charging voltage on maintenance free period 1.46 Float charge voltage per cell Maintenance free period (years) Temperature 20 C Graph 3 8

11 8.0 Battery charging In order to achieve the ultra low maintenance properties of the VRPP battery, it is necessary to control the charge input to the battery to minimize the rate of water loss during the life of the product. Therefore it is important to adhere to recommended charge conditions. 8.1 Charging methods VRPP batteries may be charged by the following methods: A) Two rate charging: The initial stage of two rate constant potential charging consists of a first charging stage, with a current limit of 0.1 C to a maximum voltage of 1.45 V/cell. 5 Alternatively, if a faster rate of recharge is required, a voltage limit of 1.55 V/cell can be used. However, if frequent recharges are required this will increase the rate of water loss. After this first stage the charger should be switched to a second maintenance stage at a float voltage in the range of 1.41 to 1.43 V/cell. After a prolonged mains failure the first stage should be reapplied manually or automatically. B) Single rate charging: VRPP batteries may be float charged at 1.41 to 1.43 V/cell from a fully discharged condition to a high stage of charge. This is detailed in section 7.2 and about 80% of the capacity will be available after 16 hours of charge. Alternatively, VRPP can be float charged at 1.45V/cell if a faster recharge time is required. This will, however, increase the rate of water loss and reduce the maintenance interval by a factor of two. Temperature compensation may be required as described. 8.2 Charge acceptance The performance data sheets for VRPP are based upon several months floating and so are for fully float charged cells. A discharged cell will take a certain time to achieve this and graph 4 gives the capacity available for the two principal charging voltages recommended fo VRPP, 1.42 V/cell and 1.45 V/cell, during the first 30 hours of charge from a fully discharged state. If the application has a particular recharge time requirement then this must be taken into account when calculating the battery. 9

12 Available capacity (% of rated capacity) Charging voltage 1.45 Volts per cell Charging voltage 1.42 Volts per cell Current Limit 0.1 C 5 A Temperature 20 C Charge time (hours) Available capacity on float charge from a fully discharged cell Graph Commissioning requirements Batteries filled and charged VRPP batteries are normally supplied charged, ready for immediate use and provided they have not been stored for more than six months, they may be put directly into service on float charge. Under these circumstances they should not be given a commissioning charge before putting into service. Batteries stored between six and twelve months should be treated as batteries filled and discharged Batteries filled and discharged Batteries in a filled and discharged state require a commissioning charge prior to putting into service. This is a once only operation and is essential to prepare the battery for its long service life. The commissioning charge requires an input of 160% of the rated (C ) capacity before putting the battery 5 into service. Prolonged overcharging is not harmful to VRPP batteries are normally supplied charged but will reduce the initial electrolyte reserve and thus service life without topping up. The following methods of commissioning charge are recommended a. Charge 16 hours at 0.1 C A maximum. 5 b. Charge at 1.65 V/call for 16 hours maximum (0.1 C A current limit) 5 If these recommended methods are not available in practice, then charging may be carried out at lower float voltages for extended periods. 10

13 9.0 Special operating factors 9.1 Electrical abuse Ripple effects The nickel-cadmium battery is tolerant to high ripple from standard charging systems. VRPP batteries have been tested with voltage ripple values of up to 15% without any effect on water loss. ver discharge If more capacity is drawn out than the rated capacity, the battery is said to be over discharged. This abuse situation should be avoided. In the case of lead acid batteries this will lead to failure of the battery and is unacceptable. The VRPP battery is designed to make recovery from this situation possible. ver charge vercharge of the battery will increase the water loss of the system. In case of VRPP battery, with its generous electrolyte reserve, a small degree of overcharge will not significantly alter the maintenance period. In the case of excessive overcharge, a situation which will immediately destroy a valve regulated lead acid battery, VRPP can be refurbished as described in section Mechanical abuse Shock load The VRPP block battery concept has been tested as per IEC (bump tests at 5 g, 10g and 25 g) and IEC 77 (shock test 3 g). Vibration resistance VRPP cells are tested as per IEC 77 for 2 hours at 1 g. External corrosion VRPP batteries are manufactured in durable polypropylene, all external metal components are nickel-plated and these components are protected by a neutral grease and a rigid plastic cover. 11

14 10.0 Installation and storage 10.1 Emplacement The HBL NIFE brand VRPP valve regulated recombination battery can be fitted onto stands, can be floor mounted or can be fitted into cabinets. Local standards or codes normally define the mounting arrangements of the batteries, and these must be followed if applicable. However, if this is not the case the following comments can be used as a guide. When the battery is housed in a cubicle or enclosed compartment, it is necessary to provide adequate ventilation depending on utilization. Allow sufficient space over the battery to ensure easy access during assembly. HBL NIFE offers a wide selection of stands to suit most applications. It is desirable to have easy access to all blocks on a stand mounted battery and they should be situated in a readily available position. Distances between stands, and between stands and walls, should be sufficient to give good access to the battery. The overall weight of the battery must be considered and the load bearing on the flooring taken into account in the selection of the battery accommodation. In case of doubt, please contact HBL NIFE for advice. When mounting the battery ensure that the cells are correctly interconnected with the appropriate polarity. The battery connection to load should be with nickel-plated cable lugs. Recommended Torque Cell connection bolt Recommended Torque per pole Nm lbf.in M M8 20 M Table 1 To avoid accelerated ageing of the plastic due to UV light, batteries should not be exposed to direct sunlight, UV light sources or strong daylight for prolonged periods. 12

15 10.2 Ventilation Under normal floating conditions the HBL NIFE VRPP battery gives off up to 10 times less gas than a conventional open cell. Thus the need for ventilation is much reduced and in many cases no special ventilation requirements other than normal room ventilation are required. The quantity of hydorgen given off is given in section 7.8, Gas evolution. However, if the VRPP battery is commissioned in the final location or if the maximum recommended charge current of 0.1 C is used then the quantity of gas given off will be 5 increased. A typical figure for room ventilation is about 2.5 air changes per hour and under such conditions it is satisfactory to install 700 watt hours of battery capacity per cubic meter if the final charge current is at 0.1 C A. 5 Please refer to ventilation standards and requirements applicable in your country or area. Care should also be taken with cubicle installations to ensure sufficient ventilation and battery spacing to prevent overloading and, hence, excess water usage Storage VRPP batteries are normally supplied filled with electrolyte and charged ready for immediate use. They may be stored in this condition for up to twelve months from the date of despatch from HBL NIFE. If batteries are not put into service immediately, they should be stored in a clean, dry cool (+10 C to +30 C) and well ventilated store on open shelves. They should not be exposed to direct sunlight. Before storage ensure that the batteries are clean, with on adequate protective finish, such as an approved neutral grease, on the connectors, and that the flame-aresting low pressure vents remain undisturbed. Batteries filled and charged can be stored for up to one year without any conditioning charge requirement. If they are stored up to six months they should be put directly into service without any commissioning charge. If they have been stored for between six months and one year they should be given and commissioning charge as described. Before putting into service ensure that the batteries are externally clean and with an adequate protective finish, such as an approved neutral grease, on the connectors. If it is necessary to store the batteries for more than one year then they should be given the following conditioning discharge/charge cycle at the end of each year of storage: - Discharge at 0.1 C A to an end of discharge voltage of 1.1 V/cell, where C is the rated 5 5 capacity of the battery - Charge 160% battery s rated capacity at a maximum of 0.1 C A for 16 hours 5 - Return battery to store - Repeat every 12 months Storage at temperatures above +30 C can result in loss of capacity. This can be as much as 5% per 10 C above +30 C. 13

16 11.0 Maintenance of VRPP batteries in service VRPP Battery requires minimum of attention if properly designed for the application. However, it is good practice with any standby system to carry out a full discharge - charge cycle once per year to make sure that charger, battery and ancillary electronics are functioning correctly. It is recommended that for system servicing, electrolyte levels should be visually checked and ensure that level is above the minimum, battery should be checked for external cleanliness and if necessary clean with damp cloth. If there is evidence that electrolyte has been ejected from vents or that there has been excessive of water this could indicate a charger or system malfunction. Action should be taken to rectify this Refurbishment of VRPP battery Refurbishment of the VRPP battery is recommended when the electrolyte level reached the normal minimum mark on the cell but must be carried out before it reached the warning level on the cell. Batteries operated at float charge rates above 1.42 V/cell will require refurbishment during their operating life. Refurbishing of the VRPP battery is carried out as follows: 1. Disconnect the battery from the load. Remove the terminal cover. 2. With the terminal cover removed, the tops of the individual cells of the VRPP battery will be in view. 3. Confirm that an adequate protective finish remains on glands, poles and connectors. Replenish if necessary. 4. Carefully loosen the flame-arresting low pressure vents to release any gas pressure and then remove each vent completely and retain for refitting. 5. Top-up each cell with distilled or de-ionized water to the specified maximum level. 6. Wipe up any small spillage on cells using a clean cloth. Replace the vents taking care to tighten them correctly i.e., Until resistance against a stop is experienced, and ensure that the seating rubber has not been disturbed out of position. If there is any doubt about the quality of the sealing ring replace with a new vent assembly. 7. Replace the terminal cover. The refurbished VRPP battery is now ready for re-commissioning. 14

17 VRPP Range Cell dimensions and weight Cell type Capacity at the 5 hr rate (Ah) Cell dimensions in mm Length Width 1.2 V 2.4 V 3.6 V Height Approx weight (1.2V Block) in kgs Container reference Reserve electrolyte cc/cell VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B31 0 VRPP B31 0 VRPP B31 0 VRPP B31 0 VRPP B31 0 VRPP B41 0 VRPP B41 0 VRPP B41 0 VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B VRPP B In accordance with its policy of continuous improvement the company reserves the right to change specifications and designs without notice. Illustrations, data, dimensions and weights given in this brochure are for guidance only and cannot be held binding on the company. 15

18 16 Cell Performance Data Discharge data is for cells after floating at 1.42 Volts Available amperes at 20 C (68 F) fully charged End Voltage 1.00V/cell Hours Minutes Seconds Cell Type C 5 Ah VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP VRPP 680 VRPP 712 VRPP

19 17 Cell Performance Data Discharge data is for cells after floating at 1.42 Volts Available amperes at 20 C (68 F) fully charged End Voltage 1.05V/cell Hours Minutes Seconds Cell Type C 5 Ah VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP VRPP 680 VRPP 712 VRPP

20 Cell Performance Data Available amperes at 20 C (68 F) fully charged End Voltage 1.10V/cell Cell Type C 5 Ah Hours Minutes Seconds VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP 680 VRPP VRPP VRPP Discharge data is for cells after floating at 1.42 Volts 18

21 Cell Performance Data Available amperes at 20 C (68 F) fully charged End Voltage 1.14V/cell Cell Type C 5 Ah Hours Minutes Seconds VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP 680 VRPP VRPP VRPP Discharge data is for cells after floating at 1.42 Volts 19

22 Cell Performance Data Available Watts at 20 C (68 F) fully charged End Voltage 1.00V/cell Cell Type C 5 Ah Hours Minutes Seconds VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP VRPP 680 VRPP 712 VRPP Discharge data is for cells after floating at 1.42 Volts 20

23 Cell Performance Data Available Watts at 20 C (68 F) fully charged End Voltage 1.05V/cell Cell Type C 5 Ah Hours Minutes Seconds VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP VRPP 680 VRPP 712 VRPP Discharge data is for cells after floating at 1.42 Volts 21

24 Cell Performance Data Available Watts at 20 C (68 F) fully charged End Voltage 1.10V/cell Cell Type C 5 Ah Hours Minutes Seconds VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP VRPP 680 VRPP 712 VRPP Discharge data is for cells after floating at 1.42 Volts 22

25 Cell Performance Data Available Watts at 20 C (68 F) fully charged End Voltage 1.14V/cell Cell Type C 5 Ah Hours Minutes Seconds VRPP 8 VRPP 10 VRPP 13 VRPP 16 VRPP 19 VRPP 24 VRPP 28 VRPP 32 VRPP 36 VRPP 40 VRPP 46 VRPP 50 VRPP 55 VRPP 61 VRPP 78 VRPP 82 VRPP 88 VRPP 92 VRPP 96 VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP VRPP 264 VRPP 276 VRPP 292 VRPP VRPP 320 VRPP 328 VRPP VRPP 356 VRPP 368 VRPP 388 VRPP 408 VRPP 432 VRPP 456 VRPP 464 VRPP 472 VRPP 492 VRPP 512 VRPP 524 VRPP 540 VRPP 552 VRPP 564 VRPP 580 VRPP 600 VRPP 612 VRPP VRPP 680 VRPP 712 VRPP Discharge data is for cells after floating at 1.42 Volts 23

26 Battery arrangement as per rack design CNT. REF 1 TIER 2 TIER 1 STEP 2 STEP 3 STEP 4 STEP 1 STEP 2 STEP 3 STEP 4 STEP W H W H W H W H W H W H W H W H B21/B B23/B24 B31/32, B B41/ B B B B B B B B B B Calculation of length : length of rack = (x + 5) x no. of block cells in a row ( for all block cells ) Where x = length of cell or block cell for row-wise mounting ( i.e. For B 31, B 32-1, B 41, B 21-1, B 23-1, B 24-1) = width of cell or block cell for cross-wise mounting ( i.e. For B 31-2,3,4 & B 41-2,3,4,5,6 ) The value of length should be rounded-off to nearest to 50 mm and 5mm should be added. Important changes : 1. For single tier racks lower step gable height increased to 300mm instead of 115mm for better accessibility of bottom row cells and terminal assembly. 2. But for two tier racks lower step gable height is maintained as 115mm since terminal assembly will be provided on the upper tier. 3. Rack legs or side supporters assembled to inside, reducing the width of rack by angle width. 4. The changes have been taken into consideration while calculating above dimension. 1 step, 1 tier rack 1 step, 2 tier rack 2 step, 1 tier rack 2 step, 2 tier rack 3 step, 1 tier rack 3 step, 2 tier rack 4 step, 1 tier rack 4 step, 2 tier rack 24