Project 1 Mechanical design of battery pack

EV LIVE BATCH:-21

1. Battery pack capacity: 18 kWh

Cell: ANR26650M1-B

Prepare a detailed battery pack drawing along with its enclosure. State your assumptions.

Ans:- Project 1

Aim:-

Aim of this project is to design a Battery Pack Mechanically using ANR26650M1-B cell model.

Objective:-

• We have to construct a battery pack of capacity 18 kWh using cell model of ANR26650M1-B.
• Prepare a detailed battery pack drawing along with its enclosure. State your assumptions.

• When we searched for the datasheet of ANR26650M1-B cell module then we got some specification such as:-

(1) Figure 1:- Datasheet

---------------------------(Figure 1)

from this table (Figure 1) we can conclude that,

• Dimension of the cell is 26*65mm
• Weight of a single sell is 76g
• cell capacity is 2.5/2.4 Ah
• Nominal voltage of a single cell is 3.3 Volt
• Power is 2600 W/kg
• Manufacturer of this ANR26650M1-B cell module is A123 SYSTEMS.

(2) Figure 2:- Graphs

From figure 2, there are 3 types of graphs are given such that Constant power discharge characterstics at 23 degree celcious (Capacity Vs Voltage), 2.5C constant Current discharges at various temperature (Capacity Vs Voltage) & Cycle life performances at 100% DOD ( cycles Vs % Nominal capacity).

from this plots we can determine the performance of ANR26650M1-B cell at various conditions.

This 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 ANR26650M1-B Cell:-

Commercial Solutions -

1. a) Advanced lead acid replacement batteries for:
2. b) Datacenter UPS
3. c) Telecom backup
4. d) IT backup
5. e) Autonomously guided vehicles (AGVs)
6. f) Industrial robotics and material handling equipment
7. g) Medical Devices

Government Solutions -

1. a) Military vehicles
2. b) Military power grids
3. c) Soldier power
4. d) Directed energy

Grid Solutions -

1. a) Frequency regulation
2. b) Renewables integration
3. c) Reserve capacity
4. d) Transmission and distribution

Transportation Solutions -

Hybrid, plug-in hybrid and electric vehicle battery systems for:

1. a) Commercial vehicles
2. b) Off-highway vehicles
3. c) Passenger vehicles

From the concept of Cell Nomenclature, we can analyse ANR26650M1-B cell as follows:-

1. A is the anode material
2. N is the cathode material made up of Nickel metal.
3. R stands for the shape of cell i.e:- cyllindrical in nature
4. 26 is the diameter of the cell in mm means Diameter is 26mm
5. 65 is the height of the cell in mm means Height is 65mm

(*) In order to design a battery pack mechanically using identical cells, we need some mathematical equations to determine all parameters such as Total Length of Battery pack, total width of battery pack, total height of battery pack, total volume required to design a battery pack, total no of cells required to design a battery pack etc.

GOVERNING EQUATIONS:-

We will use the following formulae and equations to design the battery pack:

1. Total battery pack Voltage = Nominal Voltage of a cell * number of cells in series
2. Total battery pack Capacity = Nominal cell capacity * number of cells in parallel
3. Total battery pack Energy = (Total battery pack Voltage) * (Total battery pack Capacity)
4. Battery pack Volume = Cell Volume * Total Number of cells
5. Energy Density of Battery pack = Total Number of cells * Each cell weight
6. Total weight of the battery pack = Total number of cells * each cell weight
7. Cell Volume = π(pi)*(radius of the cell)^2* height if the cell
8. Cell Energy = Cell Voltage * Cell Capacity
9. Cell Energy Density = Cell Energy/ Cell Volume

Calculation for Battery pack Design:-

From thr above Figure 1 datasheet, we can concluded that,

• Cell Diameter = 26mm = 0.026 meter
• cell radius = cell diameter/2 = 0.026/2 = 0.013 m
• cell height = 65mm = 0.065 m
• Weight of a cell = 76 gm
• cell capacity = 2.5/2.4 Ah
• cell Nominal voltage = 3.3 Volt
• Power = 2600 W/kg

(1) Volume of single cell = π(pi)*(radius of cell)^2*height of cell

= 3.14*(0.013)^2*0.065

= 3.45 * 10^-5 m

∴ Volume of single cell = 3.45*10^-5 m

(2) Cell Energy = (Cell nominal voltage)*(Cell capacity)

= 3.3 * 2.5

= 8.25 Wh

∴ Cell Energy = 8.25 Wh

• Now we have to construct a battery pack of capacity should be 18 kWh

so Total Battery Pack energy = 18000 Wh

Let's consider the Voltage of the battery pack is 180 volt.

so, Battery pack capacity will be = (Total Battery pack capacity) / (Battery pack voltage)

= 18000 / 180

= 100 Ah

∴ Battery pack capacity = 100 Ah

Now we can say that we have to make a battery pack which has a capacity of 100 Ah

in order to do that, we have to calculate total no of cell required, no. of series connection & no. of parallel connection

(5) No. of series connection = (Total Battery pack capacity) / (Cell capacity)

= 100 / 2.5

= 40

∴ so we will require 40 no. of series connections.

(6) No. of Parallel connection = (Battery pack voltage) / (Cell Nominal voltage)

= 180 / 3.3

= 54.54 ≈ 55

∴ so we will require 55 no. of parallel connections.

So Configuration of battery pack will be 40S 55P.

(7) Total no. of cell required = (No. of series connections)*(No.of parallel connections)

= 40 * 55

= 2200

∴ We will require 2200 no of cells to design a battery pack which has a capacity of 18 kWh.

(8) Battery pack length = (No.of series connection)*(cell diameter)

= 40*0.026

= 1.04 m

∴ Length of battery pack will be 1.04 meter.

(9) Battery pack width = (No. of parallel connection)*(cell diameter)

= 55*0.026

= 1.43 m

∴ Width of battery pack will be 1.43 meter.

(10) Height of battery pack = Height of a single cell = 0.065 meter

(11) Area Required by battery pack = (Length of battery pack)*(Width of battery pack)

= 1.04 * 1.43

= 1.4872 m^2

∴ Area of the battery pack will be 1.4872 m^2

(12) Volume of the battery pack = (Area of the battery pack)*(Height of the battery pack)

= 1.4872 * 0.065

= 0.096668 m^3 ≈ 0.097 m^3

∴ Volume of the battery pack will be 0.097 m^3

(13) Weight of the battery pack = (Total no of cells in battery pack)*(Cell wight)

= 2200 * 76

= 167200 gm

= 167.2 kg

• In India, We got the Price of single ANR26650M1-B cell is ₹ 850 (from internet)

(14) Total cost of the battery pack = (Total no. of cells)*(Price of single cell)

= 2200 * 850

= 1870000 INR

so the cost of Battery pack with capacity of 18kWh in India will be ₹ 18,70,000

• Battery Pack:-

Cell	ANR26650M1-B
Battery pack Energy	18 kWh
Battery pack voltage	180 volt
Battery Pack capacity	100 Ah
No. of series connection	40
No of parallel connection	55
Total no of cell required	2200
Battery Pack Length	1.04 m
Battery Pack Width	1.43 m
Battery pack Height	0.065 m
Area of battery pack	1.4872 m^2
Volume of Battery pack	0.097 m^3
Weight of battery pack	167.2 kg
Price of Single cell in India	₹ 850
Cost of Battery pack in India	₹ 18,70,000

Conclusion:-

• We have sucessfully analysed the calculations to design a battery pack wih a capacity of 18 kWh
• Here we have assumed the voltage of the battery pack as 180 volt.