Project 1 Mechanical design of battery pack
1.
Specification of cell ANR26650M1-B
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Voltage: |
3.3 Volts |
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Capacity @ 25°C: |
2.56 Ah |
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Energy @ 25°C: |
8.25 Wh |
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Energy @ 25°C: |
8.25 Wh |
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Specific Power: |
>4000W/kg | (@ 25°C, 2 sec pulse) |
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Impedance: |
>6mΩ | (1kHz AC) Typical) |
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Cycle Life: |
> 4000 Cycles | (@ 1C/1C, 100% DOD) |
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Dimensions |
|
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Height (max): |
65.15 (+/- 0.5 mm) |
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Diameter (max): |
25.96 (+/- 0.5mm) |
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Product Weight: |
76.0 (+/- 1.0 g) |
Calculation as per 18KWH battery pack:
a single cell capacity = 8.5wh
Volumetric energy = cell energy(single)/volume(single cell)
= 8.58/0.03451m^3
= 248.62wh/m^3
Gravimetric energy = single cell energy / single cell mass
= 8.85/0.076
= 112.89 wh/kg
Assuming vechicle run distance = 250km
Assuming vechile nominal voltage =145 v(serise)
energy per km = 18000/250 = 72 wh/km
For getting Nominal voltage no of cell required = 145/3.3=43.9=44 cells(series)
Total energy of 44 cells = 44*8.58wh = 384.3wh
No of cell in paralla = 18000/384.3=~ 47 cells
Battery pack capacity = no of cell in paralla * single cell capacity
= 48 *2.6 = 122 Ah
Total number of cells required for it is = 47 x 44 =2068
Weight of battery pack = 2068 * 0.076 = 157 kg
total valume of the batterypack = 2068 * 0.0345 = 2.89 m^3
cell peak current = c rate x single cell capacity = 20*2.6 =52 A
battery pack peak current =52 *47 = 2444A
battery peak power =2444*145 =354W
battery continuos current = 26 *48 =1248A
battery contious power = 1248 * 145.2 =18.12 kwh
for the arrangements of serise paralla battery we used the nickel strip connectors to connect the cell in serise and in paralla and using a module regarding thermal management and case for holding all batteries.
