YUASA Technical Centre Europe
YUASA
YUASA Technical Centre Europe
CONTENTS:
1. Chemistry
2. Construction
3. Factors affecting
6. Maintenance
7. End-of-Life
8. Series & Parallel
life
4. System
requirements
5. Installation
strings
9. Temperature
compensation
10.Load testing
11.The right battery
for the job
YUASA Technical Centre Europe
1. Basic Chemistry of a Lead-Acid Battery
Charged Condition
Positive
Active
Material
PbO2
Lead
Dioxide
Negative
Active
Material
Electrolyte
+
2H2SO4
Sulphuric
Acid
(Dilute)
Discharged Condition
+
Discharge
Pb
Lead
(Porous)
Positive
Active
Material
PbSO4
Charge
Lead
Sulphate
Negative
Active ENERGY
Material
Electrolyte
+
2H2O
Water
+
PbSO4
Lead
Sulphate
ENERGY
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2. Construction
2.1 Conventional vented lead-acid cell:
Terminals:
Container:
Rigid, acid-resistant material.
(e.g. Glass, Vulcanised Rubber,
Plastics)
Separator:
Porous, electrically insulating
material.
(e.g. Wood, Resin-Impregnated
Paper, Plastics)
Negative Electrode:
Porous Lead
Paste (Pb)
Vent Plug
Electrolyte:
Dilute Sulphuric Acid
(H2SO4)
Positive Electrode:
Lead Dioxide (PbO2)
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2. Construction
2.1 Conventional vented lead-acid
cell:
Gasses escape
Gasses bubble up through
the electrolyte and escape
through the vent.
Hydrogen:
Evolved on the negative
plate electrode
Oxygen:
Evolved on the positive
plate electrode.
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2. Construction
2.2 Valve Regulated Lead-Acid cell:
Terminals
Container:
Rigid, acid-resistant
material.
(e.g.ABS,Polypropylene)
Vent, One-way pressure
relief valve
Separator:
Micro-Fine Absorbent
Glass Mat (AGM),
Impregnated with
Dilute Sulphuric Acid
(H2SO4)
Negative Electrode:
Spongy Lead (Pb)
Positive Electrode:
Lead Dioxide (PbO2)
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2. Construction
2.2 Valve Regulated Lead-Acid cell:
Terminals
Container:
Rigid, acid-resistant
material.
(e.g.ABS,Polypropylene)
Vent, One-way pressure
relief valve
Separator:
Micro-Fine Absorbent
Glass Mat (AGM),
Impregnated with
Dilute Sulphuric Acid
(H2SO4)
Negative Electrode:
Spongy Lead (Pb)
Positive Electrode:
Lead Dioxide (PbO2)
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3. Factors Affecting Service Life
3.1 Temperature
3.2 Charge voltage
Temperature compensation
3.3 AC Ripple current
3.4 Discharge,
Depth of discharge
Frequency of discharge
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3.1 Temperature effect on battery life:
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3.2 Charge voltage: Temperature compensation
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3.3 AC Ripple current
 AC Ripple current from Rectifier and/or Inverter
 Causes heating within:




Terminals;
Inter-Cell Connectors;
Cell Group Straps;
Plate Grids
Small Batteries (≤ 12Ah) < 0.10C (A) AC
Large Batteries (> 12 Ah) < 0.05C (A) AC
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3.4 Discharge:
Depth & Frequency of Discharge
A cat is said to have 9 lives
A VRLA Battery has 2 lives:
Floating
Cycling
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3.4 Discharge:
Depth & Frequency of Discharge
 Don’t use-up the battery life just testing it
 VRLA Batteries don’t fail suddenly and
catastrophically –
 Cycle Life – 100 to 200 cycles (depending
on DOD)
 Recommend a maximum of 1 Load Test
Discharge every 6 months,
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4. System Requirements:
 System Load (k.VA - AC),
 Autonomy (hours : minutes),
 Cut-off voltage (V/cell),
 Environment (temperature – mean &
range),
 UPS unit required,
 Battery required  sizing (k.Watt - DC).
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5. Planning:- Installation:
 Location.
 Where?
 Access?
 Room size.
 Other equipment?
 Floor area.
 Floor loading.
 Batteries are HEAVY
 Battery design.
 Model.
 Cells per string.
 No. of parallel strings.
 Accommodation.
 Open Rack or cabinet.
 No. of rows per tier or
shelf.
 No. of tiers or shelves.
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6. Inspection & Maintenance:
 VRLA batteries are NOT maintenance free,
 A good maintenance scheme,




Will identify problems early,
Will allow replacement of premature failures,
Will enable of end of life prediction,
Will improve the Customer’s Comfort Factor.
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7. End-of-Life:
 Prediction of EOL is possible if Inspection
and Maintenance data is:




Done according to procedure every time
Obtain good quality data
Analysed correctly
Interpreted correctly
 VRLA MUST be separated from WEEE
and collected for recycling
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8. Installation – On site:
8.1 Single, Series String Connection.
 Rules for cells and blocs:




Same manufacturer – e.g. Yuasa
Same series or range – e.g. SWL
Same capacity/size – e.g. SWL1100
Age – new cells or blocs for new installation,
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UPS
8.1 Single, Series String Connection
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8. Installation – On site:
8.2 Parallel String Connections:
 Rules for cells and blocs:
 Same manufacturer and series – Yuasa SWL.
 Same series string voltage – e.g. 360V
nominal.
 Up to 5 parallel strings: ensure even
temperature distribution, balanced strings for
voltage and current
 Seek advice if more than 5 parallel strings
required.
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8.2 Parallel String Connections:
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9. Temperature compensation:
 The applied charge voltage should be
compensated for variations in BATTERY
temperature - not ambient temperature.
 Linear temperature compensation factor
is:
λ = -3mV/cell/ºC deviation from 20ºC.
e.g. NP/NPL/SWL Vflo(30ºC ) = 2.245V/cell
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9. Temperature compensation:
Figure 11
[1] Temperature sensor
on the +ve or –ve
terminal
Position of the temperature sensor
[4]
[2] Temperature sensor
on the end wall of the
battery case.
[3] Temperature sensor
on the front or back wall
of the battery
[4] Temperature sensor
on top of the lid of the
battery.
[5]
[1]
[5] Temperature sensor
not on the battery but
very close to it. Inside
the battery cabinet or on
the battery rack.
[2]
[2]
[3]
[6] Temperature sensor
in the battery room but
not close to the battery.
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10. Commissioning & Load Testing:
 Why do it?
 To demonstrate to the customer that the Battery
& UPS performance complies to specification.
 There are 3 methods of load testing
 Running from the system load,
 AC load frame running from the UPS,
 DC load frame running from the battery only.
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11. Choosing the right battery for the job
 Just as the internal combustion engine can be
designed and engineered for different
applications – so can the lead-acid battery
 VRLA Batteries are a mature, robust technology
– they can be designed for SLI, Cyclic and
Standby applications
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11. Choosing the right battery for the job
 UPS Applications are typically 5 ~ 90 min





durations – i.e. HRD with short autonomy
Customers also want long life batteries
YUASA’s SWL Series was designed to meet the
demanding requirements of UPS applications
Rating is 10-min rate to 1.60V/cell at 20°C
2  6V blocs: 1850-6 ; 2500-6
11  12V blocs: 750 ; 1100 ; 1850 ; 2250
780 ; 1800 ; 2300 ; 2500 ; 3300 ; 3800 ; 4250
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The End
Thank you for your attention