VRLA Battery Basic Information

8/4/2019 VRLA Battery Basic Information

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VRLA BatteryBasic Information

Boowen Lee

Battery Product Marketing Section

Emerson Network Power Co.,Ltd.


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PartI: Concept of Battery

Part II: VRLA Battery Sealing Mechanism

Part III: VRLA Battery Construction

Part IV: VRLA Battery Charge and

Discharge Characteristic

VRLA Battery Basic Information


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Battery Cell

Cell

An assembly of electrodes andelectrolyte which constitutes thebasic unit of a battery

Battery

Electrochemical power source

Receives, stores, and deliverselectrical energy

Includes one or more cells

StringSeries connection of batteries

Two dissimilar metals +electrolyte

v

=1cell

Positive plate

With higherpositive voltage

Electrical Chemical

Energy Energy

e-


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Positive platelead dioxidePbO2

Negative plateleadPb

electrolytesulfuricH2SO4solution

12v

-+ -+

12v=24vseries connection:

voltage =Vb1+Vb2+nV

Lead-Acid Battery

Form 2V cell

Negative plate Positive plate

6 cells=12V battery

C

+- -+

C=2C

parallel connection:

Capacity=Cb1+Cb2+=nC


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Lead-Acid Batterytwo general type

Flooded Batteryor wet type or open vented type

VRLA BatteryValve Regulated Lead-Acid Battery


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Flooded Battery


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Flooded Batteryused with DC Power


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VRLA Battery


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VRLA Batteryused with UPS

UPS Battery


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VRLA Batteryused with DC Power


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Earlier technology

Need separate battery room

Two type battery comparison

VRLA type

VRLA battery has substitute the flooded battery in many fields

Need maintenance periodically

Flooded type

Need additional safety measure

Keep vertical stand state

Need excess connection cable

Oxygen recombination technology

May apply near the equipment

No water replenish needed

Acid filtrate and anti-explosion prevention

May install horizontally

May use inside the load


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Two VRLA Battery type

AGM type

high energy ratioaccording to

volume or weight

support fast charge

adapt to low temperatureenvironment

middle degree discharge is

recommendedsensitive to high temperature

GEL type

adapt to deep cycle discharge

may applied to high temperature

environment

fit in with little current dischargemode

no oxygen recombination

reaction occur at initial periodrandom gas channel


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Part I: Concept of Battery

PartII: VRLA Battery Sealing Mechanism

Part III: VRLA Battery ConstructionPart IV: VRLA Battery Charge and




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Double sulfate theory

sulfuric acid in the electrolyte acts both the ion transmission medium and the reactant

positive plate material PbO2 and negative plate material Pb are both turned to PbSO4

discharge

PbO22H2SO4Pb PbSO42H2OPbSO4charge

(lead dioxide) (sulfuric acid) (spongy lead) (sulfate) (water) (sulfate)

active material electrolyte active material active material electrolyte active material

positive plate negative plate positive plate negative plate


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Substance change in positive plate

discharge


charge

Full charge Discharge(1)

Discharge(2)Discharge(3)Re-charge


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discharge


Substance change in negative plate

charge

Full charge Discharge(1)

Discharge(2)Discharge(3)Re-charge


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Electrode reaction after full charge

Positive Plate Separator Negative Plate

Oxygen Gas

Hydrogen Gas Positive Plate

2H2O O2 (oxygen

gas) + 4H+ + 4e-

Negative Plate

4H+ + 4e- 2H2

(hydrogen gas)


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Positive Plate AGM Separator Negative Plate

O2

Oxygen recombination in VRLA Battery

The amount of spongy lead used for absorbingthe oxygen yielding at the positive plate

&

The amount of spongy lead creating at negativeplate during charge process

When they reach chemical balancethe battery will

be kept sealing.


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Process of Oxygen Recombination

1Reaction at positive plateyielding oxygen 2H2O O2 + 4H

+ + 4e-

moves towards the negative plate surface through the separator

2Reaction at negative plate 2Pb + O2 2PbO chemical reaction of spongy lead with oxygen

2PbO + 2H2SO4 2PbSO4 + 2H2O (chemical reaction of PbO with electrolyte)

to reaction

2PbSO4 + 4H+ + 4e- 2Pb + 2H2SO4 (deoxidize of PbSO4 )

to reaction to reaction

3Total reaction at negative plateO2 + 4H + 4e 2H2O


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PartIII: VRLA Battery ConstructionPart IV: VRLA Battery Charge and




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Battery appearance

Handle

Short prevention lid

Outer terminal

ABS container

Label


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Interior Structure of VRLA Battery

container & cover terminal

strap/group bar

Positive & negative platesAGM

safety valve


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structure radial structuresuit for highcurrent(power) discharge.

grids structuresuit for deepdegree discharge.

lug

frame

thickness thin plate suit for highcurrent(power) discharge.

thick platewith higher floatcharge life.

Grids


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Positive Plate

Pastelead oxide (PbO)

Formationlead dioxide( PbO2)

Negative Plate Pastelead oxide (PbO)

Formationlead (Pb)

Additionxylogen/carbon black and

barium sulfate

Plate

substance molecule weight density volume ratio compare with Pb

Pb 207.2 11.34 1

PbO 223.2 9.64 1.26

-PbO2 239.2 9.37 1.32-PbO2 239.2 9.3 1.40

PbSO4 303.3 6.29 2.64


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Keep isolation of plates

Adsorb & hold electrolyte

Channel of O2 from positive plate to negative plate

Pact the active material, avoid it loosening & shelling

Prevent dendrite shorts

Separator

Positive plate

Negative plate

Separator

Separator material pore degree() pore size (m) resistance(/cm2)

Tiny hole PVC 80 3 0.18

Tiny hole polythene 63 1 0.15

Non-woven ethene 60 12 0.21

Non-woven glass mat 65 20 0.18

AGM 90 24 0.1


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composing

H2SO4 + H20

alleviantNa2SO4

Electrolyte

electrolyte acts both the ion transmission medium and the reactant

Relationship between Specific Gravity and Open circuit voltage

OCVSG + 0.84 SG effects the voltage value & batterydischarge performance

SG effects the freezing point of electrolyte( SG=1.300, freezing point= -68. 9 )

SG effects the erosion rate of plates

0

0.2

0.4

0.6

0.8

0 .9 1 1 .1 1 .2 1 .3 1.4 1 .5

H2SO 4Density

wt.%

0

0 .2

0 .4

0 .6

0 .8

w t.% * 1 0 c on d uc tiv ity m h o s/c m s olu b ility o f Pb SO 4 *1 0


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Container

Material in common use

ABS

Polypropylene--PP

ABS container

PP container


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Part III: VRLA Battery Construction

PartIV: VRLA Battery Charge and




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Charge mode

floatstandby chargea continuous chargeprocess of battery.

cycle chargean alternate charge process of

battery.

The battery should put into charge

soon after discharge

prevent PbSO4 re-crystallized


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Constant voltage limited current charge

20

0

60

40

120

100

80

0.1C

0.08C

0.06C

0.04C

0.02C

2.4

2.3

2.2

2.1

2.0

After 100% Discharge

After 50% Discharge

Charging Current

Charged

Volume

Charging

Current

(%) (A)Charging

Voltage

(V)

0 4 8 12 16 20 24 28 32 36

Charging Time (hours)

Charging Voltage

Charged Volume

2.23V Constant Voltage Charging at 25


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Charge voltage with temperature compensation

Ste wise Com ensation

0

5

2.23V

V

2.31V

Linear Com ensation

Temperature

V

2.10

2.30

2.20

2010 4030 50

V

35

2.19

2.35

Charge

Voltage


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discharge time

1.7

1.6

1.9

1.8

2.1

2.0

1h30min106 10 20h52

0.2C 100.3C 10

0.1C 10

1min 2 3

2.0C10

1.0C 100.6C 10

0.5C 10

8

Terminal voltage(V/cell)

Constant current discharge


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0

2

4

6

810

12

14

16

18

20

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Discharge time(min)

Term

ina

l

vo

ltage

(V)

Curre

nt(A)

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

2.1

2.3

kW

AmpsVoltageKilowatts

Constant discharge


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Relationship between battery dischargecapacity and ambient temperature

0

20

40

60

80

100

120

-30 -20 -10 0 10 20 30 40

Temperature

capacityC

10

low rate discharge 1h

------ high rate discharge 1h


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Discharge protection voltage

Discharge CurrentA Discharge Protection VoltageV/Cell

0.1C10 1.9

0.1C10 1.8

0.17C10 1.75

0.25C10 1.7

0.6C10 1.6


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Thank you!

Documents

VRLA Battery Basic Information