Project 1 Mechanical design of battery pack
AIM:
To design a battery pack of capacity 18 kWh using ANR26650M1-B cell
THEORY:
Battery Pack:
A battery pack is a set of any number of (preferably) identical batteries or individual battery cells. They may be configured in a series, parallel or a mixture of both to deliver the desired voltage, capacity, or power density.
Components of battery packs include the individual batteries or cells, and the interconnects which provide electrical conductivity between them. Rechargeable battery packs often contain a temperature sensor, which the battery charger uses to detect the end of charging.
When a pack contains groups of cells in parallel there are differing wiring configurations which take into consideration the electrical balance of the circuit. Battery regulators are sometimes used to keep the voltage of each individual cell below its maximum value during charging so as to allow the weaker batteries to become fully charged, bringing the whole pack back into balance.A well-balanced pack lasts longer and delivers better performance.
Nanophosphate High Power Lithium Ion Cell ANR26650M1-B:
A123’s high-performance Nanophosphate® lithium iron phosphate (LiFePO4) battery technology delivers high power and energy density combined with excellent safety performance and extensive life cycling in a lighter weight, more compact package. Our cells have low capacity loss and impedance growth over time as well as high usable energy over a wide state of charge (SOC) range, allowing our systems to meet end-of-life power and energy requirements with minimal pack oversizing
Applications of Lithium Ion Cell ANR26650M1-B:
COMMERCIAL SOLUTIONS
Advanced lead acid replacement batteries for:
- Datacenter UPS
- Telecom backup
- IT backup
- Autonomously guided vehicles (AGVs)
- Industrial robotics and material handling equipment
GOVERNMENT SOLUTIONS
- Military vehicles
- Military power grids
- Soldier power
- Directed energy
GRID SOLUTIONS
- Frequency regulation
- Renewables integration
- Reserve capacity
- Transmission and distribution
TRANSPORTATION SOLUTIONS
- Hybrid, plug-in hybrid and electric vehicle battery systems for:
- Commercial vehicles
- Off-highway vehicles
- Passenger vehicles
Datasheet:
Data sheet link : https://www.batteryspace.com/prod-specs/6610.pdf
Design Calculations:
we have,
cell radius = 0.013 m
cell height = 0.065 m
cell capacity = 2.5/2.4 Ah
Weight of cell = 76 g
Nominal Voltage = 3.3 V
power = 2600 W/Kg
therefore, cell volume = π * cell radius * cell height
= 3.14 * 0.013 * 0.065 = 0.0026533 m^3
cell volume = `2.653 times 10^-3 m^3`
Cell Energy = cell voltage * cell capacity = 3.3 * 2.5
Cell Energy = 8.25 kW
Its been given that the capacity of battery pack should be 18kWh
so total battery energy = 18000 Wh
let us assume battery pack voltage as 150 V
So, total battery capacity = total battery pack energy/ total battery pack voltage = 18000/150
Total battery pack capacity = 120Ah
Now, calculating the no. of cells required to produce 120Ah of total capacity
no. of cells in parallel = total battery pack capacity / nominal cell capacity = 120/2.5
no. of cells in parallel = 48 cells
no. of cells in series = total battery pack voltage/nominal cell voltage = 150/3.3
No. of cells in series = 45.45 `approx 46` cells
So our battery configuration will be 46s48p cells
the total number of cells = 46*48 = 2208 cells
Calculationg The dimensions of battery pack:
length of battery pack = no. of cells in series * cell diameter = 46*0.026 = 1.196m
length of battery pack = 1.196 m
width of battery pack = no. of cell in parallel * cell diameter = 48 * 0.026 = 1.248m
width of battery pack = 1.248m
Height of battery pack = height of cell = 0.065 m
Height of battery pack = 0.065m
So, the area of battery pack = length * width of batter pack = 1.196*1.248
Area of battery pack = 1.5 m^2
Volume = Area * height of battery pack = 1.5 * 0.065
Volume of battery pack = 0.0975 m^3
Total weight of battery pack = total no. of cell * each cell weight = 2208* 0.076
Total weight of battery pack = 167.808 kg
Conclusion:
Thus we have designed a battery pack successfully which has 18kWh capacity and consists of ANR26650M1-B cells