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8/8/2019 Vrla Presentation

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EXIDE POWERSAFE VRLA STATIONARY

RANGE OF BATTERIES

- AN OVERVIEW

D.SEN CHOUDHURY

R&D CENTREEXIDE INDUSTRIES LIMITED


2/21

ACTUAL SERVICE IN INDIAN CONDITIONS

FACTORS FOR CONSIDERATION

• PROLONGED STORAGE BEFORE COMMISSIONING.

• WIDELY VARYING OPERATING TEMPERATURES.

• FREQUENT DISCHARGE.

• PERIODS OF UNDERCHARGE.

• PERIODS OF OVERCHARGE.

• INADEQUATE ATTENTION / MAINTENANCE.


3/21

DESIGN OBJECTIVES

• ADEQUATE DESIGN MARGIN.

•CHOICE OF POSITIVE ALLOY WITH RESPECT TO OPERATINGCONDITIONS.

• MORE ELECTROLYTE PER Ah ALONG WITH MAXIMISED

HEAT DISSIPATION SURFACE AREA.

• IMPROVED CYCLIC CAPABILITY WITH ENHANCED CHARGE

ACCEPTANCE.


4/21

0

20

40

60

80

100

0.5 1 1.5 2 2.5

Sn % = 1.6

C o r r o s i o n %

0

10

20

30

40

50

60

70

80

90

100

G r i d - A M b

i n d i n g t e n s i o n %

Grid-AM binding tension % Corrosion %

50

60

70

80

90

100

110

0.05 0.06 0.07 0.08 0.09 0.1

Ca % = 0.06

C o r r o s i o n %

50

60

70

80

90

100

110

T e n s i l e S t r e n g t h %

Tensile Strengt Corrosion

OPTIMISATION OF Ca & Sn CONTENT IN POSITIVE ALLOY


5/21

BOTTOM SUPPORT

SPACE FOR GROWTH

ANCHORED

TO POLE

EXIDE POWERSAFE

VRLA HAS A UNIQUE

ONE-FOOT GRID WHICH

ALLOWS FOR THE

GROWTH OF THE GRIDDURING THE SERVICE

LIFE TIME.POSITIVE

PLATE


6/21

SELF DISCHARGE & STORAGE

DESIGN CHOICES THAT DETERMINE RATE OF SELF-DISCHARGE

• GRID ALLOY COMPOSITION.

• PURITY OF ALL PARTICIPATING COMPONENTS.

• DESIGN SPECIFIC GRAVITY.

• PLATE PROCESSING METHODOLOGY.

• OPERATING TEMPERATURE.

• EXIDE POWERSAFE EPST & MST/NMST RANGE OF CELLS HAVESELF DISCHARGE RATE OF LESS THAN 2 C!" CAPACITY PER

MONTH AT 2#$C. THIS HAS BEEN SUBSTANTIATED REPEATEDLY

DURING TEC TYPE APPROVAL.


7/21

STORAGE PERIOD VIS-A-VIS COMMISSIONING CHARGE

DURATION

STORAGE TEMPERATURE% 2 - '" $C

STORAGE PERIOD LENGTH OF

INITIAL CHARGE

UPTO ' MONTHS NIL

UPTO ( MONTHS ) - !# H*+.

UPTO , MONTHS 2 - '" H*+.

UPTO !2 MONTHS ) - #2 H*+.

)V MST """Ah AT BIHARSAMSTIPUR CIRCLE 01 INSTALLED

AFTER !! MONTHS GAVE !"" CAPACITY AFTER #2 HRS FLOAT0

ON FIRST CYCLE.


8/21

THERMAL RUNAWAY:

THERMAL RUNAWAY IS A STATE OF OPERATION WHERE THE

RATE OF HEAT GENERATION INCREASES FASTER THAN HEAT

DISSIPATION. THE RESULT IS AN ACCELERATED INCREASE OF

THE TEMPERATURE UNTIL THE BATTERY IS DESTROYED.

THE MAIN CAUSE IS THE ACCELERATION OF CHEMICAL

REACTION RATES WITH TEMPERATURE ACCORDING TO THE

ARRHENIUS RATE EQUATION.THIS ACCELERATION CAN BE

TRIGGERED BY ANY ONE OF THE FOLLOWING PARAMETERS%

INCREASED BATTERY TEMPERATURE. HIGHER CHARGE VOLTAGE.


9/21

Thermal Runawa Test !ata

0

20

40

60

80

0.02 0.04 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3

!uration "#rs.$

% a t t e r T e r m

i n a l

T e m

& e r a t u o C

1 2.45 V T =25±3oC

2 2.25 V T =75 ±3oC

3 2.40 V T =75 ±3oC

!"tter#T#$e%

&MST 1000

1

'

(

Test Conditions


10/21

SUMMARISED PRODUCT FEATURES OF EXIDE

POWERSAFE ‘VRLA STATIONARY RANGE

• WIDE RANGE STARTING FROM "Ah TO """Ah.• C!" CAPACITY BY DESIGN REQUIRED TO MEET !.) VPC END CUT-

OFF.

• SELF-DISCHARGE LESS THAN 2 C!" PER MONTH AT 2 C.

• 2" YRS DESIGN FLOAT LIFE .

• CYCLE LIFE%

)" D$D - !2"" CYCLES.

" D$D - !)"" CYCLES.

2" D$D - """ CYCLES.

• THERMAL STABILITY% #2 HRS MINIMUM AT # C.

EPST RANGE COVERS !"A# TO !""A#.

MST$NMST RANGE COVERS %""A# TO """A#.

ALL CELLS COME IN 'VOLT CONFIGURATION.


11/21

NMST

THE NMST CONCEPTUALLY INVOLVES

• A MA3OR BREA4 THROUGH IN SIGNIFICANTLY IMPROVING

ACTIVE MATERIAL UTILISATION.

• THIS HAS BEEN ACHIEVED BY VERY ADVANCED PLATE

MA4ING 4NOW-HOW.

• THE SAVINGS IN SPACE ACHIEVED BY THE ABOVE IS

UTILISED TO PROVIDE MORE SEPARATOR AND HENCE MORE

ELECTROLYTE1 BESIDES FURTHER PROTECTION AGAINST

SHORT-CIRCUIT.

NMST(( THE ADVANCED VERSION OF MSTDESIGNED

• FOR LOWER FLOOR LOADING.

• FURTHER ENHANCEMENT IN ABILITY TO WITHSTAND HIGH

TEMPERATURE ENVIRONMENT.


12/21

!)V-*"""A# +NMST,

STACING OPTIONS

)**T %ATT+R, )-**R.R/0T "m

'$ 1+/G#T "T$ -*A!/0G "T2m

'$

3ST-4M'()ST *ST(+ 1335 530 1689 0.707 1.802 2.5

4ST-3M'()ST 1780 530 1298 0.943 1.819 1.9

6ST-2M'()ST 2670 530 1689 1.414 1.852 1.3

%ATT+R, !/M+0S/*0S "mm$ARRA0G+M+0T

-+0GT# 1/!T# #+/G#T

COMPARISON OF MST WITH NMST +!)V-*"""A#, :

STD ARRANGEMENT

,''T !ATT-/ ,'' ,''T !ATT-/ ,''

&T *32+ 4-GT *T+ 'A(&G *T)3

2+ &T *3

2+ 4-GT *T+ 'A(&G *T)3

2+

MST 0MST

0.707 1.991 2.8 0.707 1.802 2.5


13/21

HOW TO GET THE BEST OUT OF A D.C SYSTEM

• GOOD OPERATING PRACTICE STARTS FROM THE

COMMISSIONING CHARGING.

• MAINTAINING THE RECOMMENDED CHARGING SCHEDULE

• CARRYING OUT PERIODIC MAINTENANCE DISCHARGE &

CHARGE.

• 4EEPING THE BATTERY AS MUCH AS POSSIBLE PROTECTED

FROM DIRECT HEAT & DUST.


14/21

GOOD OPERATING PRACTICES

STORAGE BEFORE COMMISSIONING

• PREFERRED STORAGE TEMPERATURE% ! - ' C.

• CELLS TO BE STORED AND PROTECTED FROM RAIN1 DIRECT

SUNLIGHT AND DUSTY ATMOSPHERE. AVOID STORAGE AT

AMBIENTS ABOVE "C.

• FRESHENING CHARGE MUST BE GIVEN ONCE IN ( MONTHS

DURING LONG STORAGE TO OBTAIN FULL PERFORMANCE AND

LIFE. FOR REGIONS EXCEEDING "C1 FRESHENING CHARGE HAS

TO BE GIVEN ONCE IN ' MONTHS.

• RECOMMENDED FRESHENING CHARGE%

2.V - !" HOURS / 2.2'V - 2 HOURS.


15/21

OPERATING GUIDELINES

FLOAT VOLTAGE TO BE SET AT EXACT LEVEL AS GIVEN IN

THE OPERATING MANUAL. 5.6 AT AN AVERAGE AMBIENT

TEMPERATURE OF '"C1 FLOAT VOLTAGE FOR A )V

SYSTEM SHOULD BE '.7".V.

CURRENT IN AMPS SHOULD BE LIMITED TO A MAXIMUM OF

! OF THE RATED C!" Ah CAPACITY. 5.6 FOR A MST !"""

CELL LIMIT CURRENT SHALL BE SET AT !" AMPS.

RECHARGE SHALL BE ON FLOAT MODE ONLY.

MAXIMUM DISCHARGE CURRENTS TO BE LIMITED TO

! MIN% ' 8 C!" AMPS SEC% ( 8 C!" AMPS.

IN-BUILT LOW VOLTAGE TRIP ABOUT !.#VPC0

RECOMMENDED.


16/21

CHARGING FEATURES

MAX VOLTAGE RIPPLE% 2 RMS.

MAX CURRENT RIPPLE% AMPS PER !"" Ah C!" CAPACITY.

AS A RULE OF THUMB1 IF THE BATTERY NEGATIVE

TERMINAL TEMP. HAS A DIFFERENCE OF MORE THAN ' C

ABOVE THE ROOM TEMP THEN THE CHARGER IS LI4ELY TOHAVE A HIGHER RIPPLE CONTENT.

RECOMMENDED FLOAT VOLTAGES

AMBIENT RECOMMENDED FLOAT MAX. CHARGING

TEMP +C, VOLTAGE PER CELL +V, CURRENT +AMPS,- TO ! 2.2# 7 "."! ".! C

! TO 2 2.2 7 "."! ".! C

2 TO ' 2.2' 7 "."! ".! C

' TO " 2.2" 7 "."! ".! C

C% NOMINAL !" HR. CAPACITY AT 2# C


17/21

MAINTENANCE PRACTICES

OBSERVE INDIVIDUAL CELL VOLTAGES AT LEAST ONCE IN

A MONTH.

INDIVIDUAL CELL VOLTAGES AFTER COMMISSIONING MAY

VARY WITHIN A BAND OF 7 "."V ON FLOAT.AFTER ABOUT

2/' MONTHS INDIVIDUAL CELL VOLTAGES SHOULD VARYWITHIN A BAND OF 7 "."2V.

CELLS WITH ABERRANT VOLTAGE READING SHALL BE

MONITORED ON A WEE4LY BASIS. IF THE PROBLEM

PERSISTS OR DETERIORATES THE CELL MIGHT HAVE

DEVELOPED A DEFECT. REPLACEMENT OF ONE OR TWO DEFECTIVE CELLS WITHIN

YEARS OF SERVICE LIFE WILL NOT AFFECT STRING

PERFORMANCE.


18/21

MAINTENANCE PRACTICES

FULLY CHARGED CELLS SHOULD DRAW A MAXIMIUM

STEADY CURRENT OF '"-"9A/!""Ah OF C!" CAPACITY IN

NORMAL FLOAT CONDITIONS AT 2#C0

5.6 MST !""" CELL AT 2#C SHOULD DRAW ".'-".AMPS UNDER FLOAT CONDITIONS. FLOAT CURRENT

APPROX. DOUBLES FOR EVERY !"C RISE IN TEMPERATURE.

CHARGING SYSTEM SHOULD HAVE THE PROVISION FOR

MEASURING THE FLOAT CURRENT MAX AMPS0


19/21

ANNUAL MAINTENANCE PRACTICES

• TEST DISCHARGE AT C!" RATE FOLLOWED BY A

RECHARGE. THE MEASURED C!" CAPACITY IS THE MOST

ACCURATE ESTIMATION OF STATE OF HEALTH.

• TEST DISCHARGE AT C RATE FOR !" MINUTES -INDIVIDUAL CELL VOLTAGES SHOULD BE !.,V. THIS GIVES

AN APPROX. IDEA OF THE STATE OF HEALTH.


20/21

STATE-OF-THE-ART MANUFACTURING

TECHNOLOGY

EIRICH PASTE MIXING MACHINE%

CONTROLLED PASTE MIXING DONE UNDER HIGH VACUUM TO ENSURE

PERFECT CONSISTENCY BETWEEN BATCH TO BATCH IN TERMS OF MOISTURE

CONTENT1 DENSITY & OTHER PARAMETERS.

OSI CURING OVENS%

AUTOMATIC HYDRO-SETTING CYCLE WITH INCONTROLLED HUMIDITY

AND TEMPERATURE CONDITIONS FOR EXCELLENT BONDING OF THE PASTE TOTHE GRID AND GENERATION OF TETRA BASIC LEAD SULFATE IN THE PASTE.

PULSE CHARGING FOR 3AR FORMATION%

A PROPRIETARY COMPUTER CONTROLLED PULSE CHARGING METHODOLOGY

FOR VERY FAST AND COMPLETE ACTIVATION OF PASTE MATERIAL. !""

BATTERIES VOLTAGE & CURRENT DATA ARE DATALOGGED AND MONITORED

PRIOR TO DESPATCH.


21/21

FULLY AUTOMATED SHIN-OBE ASSEMBLY LINE

: ROBOT CONTROLLED STAC4ING.

: !"" GROUP COMPRESSION CHEC4.

: AUTOMATIC BOXING.: !"" SHORT-CIRCUIT TESTING.

: ARGON ARC BASED TIG-WELDING.

: AIR LEA4 TESTING.

: DOUBLE PROTECTION RESIN SEALING.

: HIGHLY RELIABLE HELIUM ION TESTING.

: VACUUM CONTROLLED ACID FILLING.

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