Monday, June 23, 2025
Alcad stationary batteries, solutions you can count on!
1xSYS_-00001
20xHB255P
Table of contents
Page
Engine starting battery sizing
2
IEC 62485-2 / EN 50272-2 ventilation requirement / heat dissipation
4
Environmental footprint
8
HB255P - Cell data sheet
11
Monday, June 23, 2025
Engine starting battery sizing
Project name
Project reference
System name
System reference
Customer
Customer reference
Sime Darby Wassana
P_26Mar25_Maven_a
SYS_-00001 - Starting
SYS_-00001
Sizing standard
IEEE1115
Battery proposal
Duty1
Proposed battery
20 x HB255P
Rated capacity
Cell height
Battery weight
255 Ah
411 mm
434.0 Kg
Definition
Manufacturer
Model
Type
Caterpillar
3516
4-cycle diesel
Sizing parameters
Engine displacement
Starter motor voltage
Number of starter motors
Charge method
Oil type
Oil temperature
Battery temperature
Total cranking time
Starter motor efficiency
Battery state of charge
Minimum cell voltage
Continuous load before starting
4210.000 Cu. inch
24 V
Dual
Floating
SAE 30
25 °C
25 °C
90 s
60 %
100 %
0.87 V
43 Ah
Note: Low voltage alarm sensors should be adjusted to allow for a 3-5 second delay during voltage recovery.
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be
modified without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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380752 27f65118-562d-4def-bab0-fcf020f516b2 Version: 3.5, Last updated on 01/2024, Referential data
6/23/2025
Monday, June 23, 2025
Engine starting battery sizing
Sizing standard
IEEE1115
Calculation parameters - HB255P
Base cranking current
1600 A
Coefficients
Motor type (4-cycle diesel)
Oil temperature (25 °C)
Battery temperature (25 °C)
Total cranking time (90 s)
Starter motor efficiency (60 %)
Battery state of charge (100 %)
Cell Number (20)
Min cell voltage (0.87 V) *
1.00
1.01
1.00
1.21
1.00
1.00
1.00
1.03
Total correction factor
1.26
Required current
Required capacity
Rated capacity
2,020 A
255 Ah
255 Ah
* Voltage drop in the load cables taken into account with 0.03 V.
The starting sizing is based on a Base Cranking Current which is related to the engine displacement. The Base
Cranking Current is multiplied with a number of coefficients which are dependent on the input parameters of the
actual sizing. The standard values gives the coefficient 1,00. Changing the input parameters results in coefficients
higher or lower that 1,00. The coefficients are multiplied to give the Total Correction Factor. The Base Cranking
Current is multiplied with the Total Correction Factor and the result is the Required Current.
The selected cell must be able to deliver the Required Current for 30 seconds with a minimum voltage of
0.87V/cell.
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be
modified without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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380752 27f65118-562d-4def-bab0-fcf020f516b2 Version: 3.5, Last updated on 01/2024, Referential data
6/23/2025
Monday, June 23, 2025
IEC 62485-2 / EN 50272-2 ventilation requirement / heat dissipation
Battery
20 x HB255P
During the last stage of high-rate charging (end of charge and during overcharge), the battery is emitting gases
(oxygen-hydrogen mixture). The purpose of ventilating a battery location or enclosure is to maintain the hydrogen gas
concentration below the 4% hydrogen threshold. Battery accommodation rooms are to be considered as safe from
explosions, when by the natural or forced ventilation the concentration of hydrogen gas is kept below this safety limit.
Note that specific local regulations for battery installation and ventilation may be valid in your area.
Hydrogen gas (H2)
Concentration
4%
LEL Value
100%
standard
IEC 62485-2 / EN 50272-2
Ventilation air flow Q
Q = v x q x s x n x Igas x Crt x 10 ̄ ³ (m³/h)
Variable
Description
Value
v = dilution factor to avoid a 4% hydrogen concentration
((100 % - 4%) / 4%)
24
q = maximum generated hydrogen for 1 Ah of overcharge per cell
assuming no gas recombination at +25 °C
1.095 x 0.42 x 10ˉ³
m³/Ah
s = general safety factor
5
n
Number of cells
20
Igas = Ifloat/Boost x fg x fs
Current producing gas during overcharge when charged with
constant voltage
vxqxs
Ifloat = current for the float charge under fully charged condition at 1.4 1 mA/Ah
V to 1.43 V at + 20 °C
IBoost = current for the boost charge under fully charged condition at
1.5 V to 1.55 V at + 20 °C
10 mA/Ah
fg = gas emission factor, proportion of current at fully charged state
producing hydrogen
1
fs = safety factor taking into account faulty cells and an ageing
5
Igas = Icommissioning
Current for commissioning at constant current charge at 0,2 C5 A
200 mA/Ah
Crt
Rated capacity
255 C5 Ah
Air flow Q (m³/h)
At float
At boost
Commissioning
1.41
14.07
56.29
Note: The charger must be protected against malfunction. If not, the ventilation should be calculated to suit the
greatest current available from the charger.
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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6/23/2025
Monday, June 23, 2025
IEC 62485-2 / EN 50272-2 ventilation requirement / heat dissipation
Battery
20 x HB255P
Number of air changes per hour
Length (m)
Width (m)
Height (m)
Volume (m³)
Battery room volume
Occupied volume
0.25
Free air volume
At float
Number of air changes per hour
At boost
Commissioning
N/A
Natural ventilation
The amount of ventilation air flow shall preferably be ensured by natural ventilation, otherwise by forced ventilation.
For natural ventilation, battery rooms or enclosures require an air inlet and an air outlet with a free area of opening
calculated by the formula A > 28 x Q (cm²). The air velocity is assumed to be 0.1 m/sec.
Free area of openings - inlet & outlet (cm²)
At float
At boost
Commissioning
1.41*28=39.4
14.07*28=394
56.29*28=1576.2
The above calculations are done according to the IEC 62485-2 standard.
Always check local regulations.
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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6/23/2025
Monday, June 23, 2025
IEC 62485-2 / EN 50272-2 ventilation requirement / heat dissipation
Battery
20 x HB255P
H2 emissions
The calculated H2 emission value is the amount of H2 that will be released from the cells under normal charging
conditions without safety factors.
H2 Emission = 0.42 x 0.001 x Crt x Ihydrogen x n dm³/h (litre/h)
Actual gassing = 0.63 x 0.001 x Crt x Ihydrogen x n dm³/h (litre/h)
Variable
Ihydrogen = Ifloat/Boostx(1-Rv)
Description
Value
Current producing gas during overcharge when charged with
constant voltage
Ifloat = current for the float charge under fully charged condition at
1.4 V to 1.43 V at + 20 °C
1 mA/Ah
IBoost = current for the boost charge under fully charged condition
at 1.5 V to 1.55 V at + 20 °C
10 mA/Ah
Rv = recombination degree, proportion of hydrogen that is
recombined into water
0.3
Ihydrogen = Icommissioning
Current for commissioning at constant current charge at 0,2 C5 A
200 mA/Ah
n
Number of cells
20
Crt
Rated capacity
255 C5 Ah
At float
At boost
Commissioning
H2 Emission (dm³/h)
1.50
15.0
428
H2+O2 Emission (dm³/h)
2.25
22.5
643
Heat dissipation
The heat dissipation during float is normally used for dimensioning the cooling system. The cells will also generate
heat during discharge and recharge but the generated heat will be absorbed by the plates and the electrolyte and will
slowly dissipate to the surrounding air.
Heat dissipation per system (W)
At float
1.43V Per cell
At boost
1.45V Per cell
At discharge
av.current of N/A
av.voltage of 1.24V
Per cell
2.2
22.7
N/A
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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6/23/2025
Monday, June 23, 2025
IEC 62485-2 / EN 50272-2 ventilation requirement / heat dissipation
Battery
20 x HB255P
Safety distance according to IEC 62485-2 chaper 7.7
Variable
Igas = Ifloat/Boost x fg x fs
Description
Value
Current producing gas during overcharge when charged with
constant voltage
Ifloat = current for the float charge under fully charged condition at 1.4 1 mA/Ah
V to 1.43 V at + 20 °C
Crt
Safety distance (mm)
NOTE
device.
IBoost = current for the boost charge under fully charged condition at
1.5 V to 1.55 V at + 20 °C
10 mA/Ah
fg = gas emission factor, proportion of current at fully charged state
producing hydrogen
1
fs = safety factor taking into account faulty cells and an ageing
5
Rated capacity
255 C5 Ah
At float
At boost
312
672
The required safety distance d can be achieved by the use of a partition wall between battery and sparking
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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6/23/2025
Monday, June 23, 2025
Environmental footprint
Battery
20 x HB255P
Global Warming Potential (GWP)
As explained in the IPPC (Intergovernmental
Panel on Climate Change (2001)), the Global
Warming Potential (GWP) is a measurement
of greenhouse gas emissions, such as CO2 and
methane. These emissions are causing an
increase in the absorption of radiation emitted
by the earth, magnifying the natural
greenhouse effect. It is expressed in kg CO2
equivalent and measures the Environmental
Footprint of a product.
Life Cycle Assessment (LCA)
As part of its environmental commitment, Alcad gives priority to recycled raw materials over virgin raw materials,
reduces its plants’ air and water releases year after year, minimizes water usage, reduces fossil energy
consumption and associated CO2 emissions, and ensures that its customers have recycling solutions for their spent
batteries.
To reach this target, Alcad is using Life Cycle Assessment (LCA) which is a standardized scientific method for the
systematic analysis of all mass and energy flows as well as environmental impacts attributed to a product system,
from raw material acquisition to end-of-life management.
To provide the best environmental information to its customers Alcad has been performing since 2010
comparative LCA of several battery technologies used for back-up solution. A third party is also involved to
perform a critical review of the data and ensure that the highest level of compliance with the ISO 14040/44
standards is met.
Data used in this comparative LCA were updated in 2017 and the previous LCA study was enlarged to more battery
types. By interpolation of these verified LCA calculations, the Global Warming Potential of different Ni-Cd and
Lead-acid batteries used for back-up applications and sized through Basics is evaluated and displayed given that
the user indicates the expected life time of the battery.
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
Visit our website at www.alcad.com
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6/23/2025
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Monday, June 23, 2025
Estimated life of Lead-Acid batteries
Estimated life for Lead-Acid batteries is based upon the half-life formula
L0=life time in years at the temperature T0
T1=temperature increase required to reduced life time with 50%
T= System design temperature is taken from the inputted value “Nominal temperature”
The constants used for VR Lead-Acid is well known facts that is found in several VR Lead-Acid manufacturers
documentation[i]. L0 = 10 years, T0 = 25 °C, T1 = 8.3 °C, T= Tnom
Number of cells and capacity comparison between NiCd and VR Lead-Acid batteries
Number of cells differs between NiCd and VR Lead-Acid batteries with the nominal voltage difference. The
conversion factor is 1.2V/2.0V = 0.6. Number of VR Lead-Acid cells is assumed to be made of 6 (12V blocks). The
capacity comparison between NiCd and VR Lead-Acid cells is assumed to be equal.
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
Visit our website at www.alcad.com
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Values/Calculations
Variable
Description
20 x HB255P
12 x VRLA 255
Cnom
Rated capacity (Ah)
255
255
N
Number of cells
20
12
Ns
Number of strings
1
1
Tnom
Nominal temperature (°C)
25
25
L
Expected battery system life
10
10
Lest
Estimated life of one battery
in the design temperature
(years)
20
10.0
L/Lest
Number of batteries needed
during life
1
1
GWP, (global
Equivalent Kg of CO2 for one
warning potential) battery
-712
448 / 1.0 = 448
GWP * L/Lest
-712 *
448
Equivalent Kg of CO2 during
estimated life of the battery
system
Comparison
-259%
* Negative result means the environmental credits from the battery recycling surpasses the GWP impact from the other phases
of the LCA (mainly manufacturing and use)
Global Warming Potential (GWP)
Equivalent Kg
of CO2
Conclusion/statement
The GWP of the proposed Ni-Cd battery shows a 259% decrease compared to the GWP of the comparable VR
Lead-Acid.
Disclaimer
The results described in this document are based on the analysis of available information. They are for
personal use and guidance only. They do not constitute any contractual representation and are not binding.
i Power Through – http://www.power-thru.com/documents/The%20Truth%20About%20Batteries%20-%20POWERTHRU%20White%20Paper.pdf
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be modified
without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
Visit our website at www.alcad.com
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6/23/2025
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Monday, June 23, 2025
HB255P - Cell data sheet
Classification
Wiring principle
Brand
Cell type
Cell P/N
Capacity at 5 hours rate
IEC Designation
According to IEC 60623
Crosswise
Alcad
HB255P
310051581
255 Ah
KH255P
Physical data
Overall height
411 mm
Cell height
410 mm
Width
195 mm
Length
159 mm
Weight per cell
21.7 Kg
No. of terminals/polarity
Terminal material
Vent type
2
Steel
Handle
Yes
Negative
Type of plates
Pocket
E13
E22
5.2 liters
Max/Min
Vent oil quantity
50 mm
50 cm3
120 mm²
End-lug (and external cable)
120 mm²
Construction
Container material
Separator type
Connection torque
Terminal size
Polypropylene
Grid
30.0 +/- 3.0 Nm
M10 SW 16 mm
Plates
Positive
Type of plates
Pocket
Electrolyte
Electrolyte type: Renewal
Electrolyte type: Initial
Electrolyte per cell: Liquid
Connection
Cable area of internal
connection cables
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be
modified without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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380752 27f65118-562d-4def-bab0-fcf020f516b2 Version: 3.5, Last updated on 01/2024, Referential data
6/23/2025
Monday, June 23, 2025
HB255P - Cell data sheet
Charging
Float voltage
Single-level voltage
1.4 V/Cell
1.43 V/Cell
High rate voltage (recommended)
1.45 V/Cell
Resistance/Short circuit
Internal resistance
0.17 mOhm
Short circuit current
7583 A
Performance data
Current discharge
After prolonged float charge of fully charged cells. Available amperes at +20°C +/- 5°C (+68°F +/- 9°F)
V/Cell
10h
8h
5h
3h
2h
1.5h
1h
30m
20m
15m
10m
5m
1m
30s
5s
1s
1
25.6
31.9
51.0
84.2
125
164
240
436
586
672
794
963 1,209 1,364 1,658 1,763
1.05
25.3
31.7
50.3
82.8
122
161
232
414
503
572
672
782 1,014 1,145 1,381 1,439
1.1
24.7
30.8
49.2
80.6
118
155
220
336
394
443
499
602
808
920 1,094 1,150
1.14
24.0
30.0
47.2
77.2
109
138
181
265
316
355
402
491
644
739
869
900
1.16
23.3
29.1
46.1
74.2
100
123
147
220
262
291
323
404
547
617
723
765
Engine starting performance
For a fully charged cell by a constant current charge according to IEC 60623 standard at +20°C +/- 5°C (+68°F +/- 9°F), 30 seconds discharge
down to 0,85 V
Available amperes
2,226 A
Power discharge
Available power (W), after prolonged float charged of fully charged cells at +20°C +/- 5°C (+68°F +/- 9°F)
V/Cell
10h
8h
5h
3h
2h
1.5h
1h
30m
20m
15m
10m
5m
1m
30s
5s
1s
1
30.9
38.6
61.0
100
147
186
261
453
600
682
800
963 1,209 1,364 1,658 1,763
1.05
30.6
38.3
60.1
98.1
145
184
259
446
536
607
710
822 1,065 1,202 1,450 1,512
1.1
29.8
37.3
58.8
95.5
140
179
250
376
438
491
551
662
889 1,012 1,204 1,266
1.14
29.0
36.3
56.4
91.5
128
161
210
305
362
405
459
560
735
842
991 1,026
1.16
28.2
35.2
55.1
87.9
118
144
172
256
305
338
375
468
635
716
839
888
Engine starting performance
For a fully charged cell by a constant current charge according to IEC 60623 standard at +20°C +/- 5°C (+68°F +/- 9°F), 30 seconds discharge
down to 0,85 V
Available amperes
2,226 A
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be
modified without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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Monday, June 23, 2025
HB255P - Cell data sheet
Kt Factor
Current discharge
After prolonged float charge of fully charged cells. Kt factor at +20°C +/- 5°C (+68°F +/- 9°F)
V/Cell
10h
8h
5h
3h
2h
1.5h
1h
30m
20m
15m
10m
5m
1m
30s
5s
1s
1
10.0
7.98
5.00
3.03
2.04
1.55
1.06
0.58
0.44
0.38
0.32
0.26
0.21
0.19
0.15
0.14
1.05
10.1
8.05
5.07
3.08
2.08
1.59
1.10
0.62
0.51
0.45
0.38
0.33
0.25
0.22
0.18
0.18
1.1
10.3
8.27
5.19
3.17
2.15
1.65
1.16
0.76
0.65
0.58
0.51
0.42
0.32
0.28
0.23
0.22
1.14
10.6
8.50
5.40
3.30
2.35
1.85
1.41
0.96
0.81
0.72
0.64
0.52
0.40
0.35
0.29
0.28
1.16
11.0
8.77
5.53
3.44
2.56
2.07
1.74
1.16
0.97
0.88
0.79
0.63
0.47
0.41
0.35
0.33
Engine starting performance
For a fully charged cell by a constant current charge according to IEC 60623 standard at +20°C +/- 5°C (+68°F +/- 9°F), 30 seconds discharge
down to 0,85 V
Available amperes
2,226 A
Power discharge
Kt factor power, after prolonged float charged of fully charged cells at +20°C +/- 5°C (+68°F +/- 9°F)
V/Cell
10h
8h
5h
3h
2h
1.5h
1h
30m
20m
15m
10m
5m
1m
30s
5s
1s
1
8.25
6.60
4.18
2.56
1.73
1.37
0.98
0.56
0.43
0.37
0.32
0.26
0.21
0.19
0.15
0.14
1.05
8.32
6.66
4.24
2.60
1.76
1.39
0.99
0.57
0.48
0.42
0.36
0.31
0.24
0.21
0.18
0.17
1.1
8.54
6.83
4.34
2.67
1.83
1.42
1.02
0.68
0.58
0.52
0.46
0.38
0.29
0.25
0.21
0.20
1.14
8.78
7.02
4.52
2.79
1.99
1.58
1.22
0.84
0.70
0.63
0.56
0.46
0.35
0.30
0.26
0.25
1.16
9.06
7.25
4.63
2.90
2.17
1.77
1.49
1.00
0.84
0.75
0.68
0.54
0.40
0.36
0.30
0.29
Engine starting performance
Kt factor power, after prolonged float charged of fully charged cells at +20°C +/- 5°C (+68°F +/- 9°F)
Available amperes
2,226 A
ALCAD confidential and proprietary. The data herein given are for information purposes only and are not binding on ALCAD. They may be
modified without prior notice. Please contact an ALCAD representative in order to obtain confirmation of the above data.
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