Project 1 Mechanical design of battery pack
Aim :-
Battery pack capacity: 18 kWh
Cell: ANR26650M1-B
Prepare a detailed battery pack drawing along with its enclosure. State your assumptions.
Objectives :-
1) Collecting the data of Cell: ANR26650M1-B from Nanophosphate High Power LithiumIon Cell PDF.
2) Calculating all Electrical parameters for 18 kWh Battery Pack.
3) Calculating all Physical dimensions for Battery Pack
Methodology :-
1) To build the Battery pack for any Electric Vehicle, we have to calculate the first proportion of power then motor power, and depend on that we will model the battery pack so we know how much power we required which is 18kWh.
2) For the 18kWh battery Pack we have to calculate how many cells are parallel and how many cells are in series.
3) After calculation of series and parallel combination we have to calculate the proper Geometry and topology consideration for assembling batteries.
Theory :-
The high voltage battery is one of the most important components of a battery electric vehicle (BEV). The battery parameters have a significant influence on other components and attributes of the vehicle, like:
- maximum traction motor torque
- maximum regeneration brake torque
- vehicle range
- vehicle total weight
- vehicle price
Pretty much all major aspects of a pure electric vehicle (EV) depend on the parameters of the high voltage battery.
Cell dimensions:-
Cell calculation:
1) Volume of the cell: For the calculation of the volume of the cell we use the formula of Volume of cylinder.
so the formula is: πr2hπr2h
From Datasheet of Cell, we have 'r' and 'h' values
r=0.013m and h=0.065m = Volume of the cell: πr2hπr2h
: 3.14⋅0.0132⋅0.0653.14⋅0.0132⋅0.065
:0.0000344929m3m3
The volume of the cell is 0.0000344929m3m3
Basically, the value of the volume of the cell is used to find out the total volume of the battery pack.
Cell Energy= Cell Capacity (Ah) × Cell Voltage (V)
= 2.5 × 3.3
= 8.25 Wh
Cell Energy is 8.25 Wh
The value of a single cell is used to calculate the total energy of the battery pack.
Single Cell Energy Density
Volumetric energy (Wh/m3) = Single Cell Energy / Volume of each cell
= 8.25 Wh / 0.0000344929m3
=2,39,179.6572 Wh/m3
Single Cell Energy Density is 2,39,179.6572 Wh/m3
Battery pack calculation:
Now we calculated parallel and series combinations so we can now calculate total no of cells required
Total no of cells: Series cells * parallel cells
:50*44
:2200.
Total no of cells required are 2200.
So from series and parallel combination, we can calculate the voltage of battery pack and the current of the battery pack.
Voltage= no of cell in series* nominal voltage.
= 50*3.3
= 165V
The total value of voltage is 165V.
Current=No of parallel cells * cell capacity
= 44*2.5
=110Ah.
The total value of Current is 110Ah
So now we can calculate the how much mount of energy this combination have by product of voltage and current, and check the it will satisfied or not our requirement
Energy= Voltage * Current
= 165 * 110
= 18150WAh
The total value of Energy is 18150WAh.
So our calculation are satisfied requirement what we need.
now we have total no of cells and volume of single cell so we can calculate the total volume required for battery pack
Total volume = no of cells * Volume of single cell
= 2200 * 0.0000344929
=0.07588438m3m3
Total volume required for battery pack is 0.07588438m3m3
We also have single cell weight from that we can calculate the total weight of battery pack without other mechanical and electrical connections.
Weight = No of cells * weight of single cell.
= 2200 * 0.076
= 167.2kg
Weight of battery pack is 167.2kg
Energy dencity= volume * battery pack energy
= 0.07588438 * 18150
= 1,377.301497kWh/m^3
Energy dencity is 1,377.301497kWh/m^3
detailed battery pack drawing along with its enclosure.
BATTERY HOLDER ,SPACER For CELL CYLINDRICAL LI-ION
Positive and Negative Clip :-
. A positive and negative clip is used to connect the battery end cap i.e (+) and (-). Design is shown below:
To make the battery pack, you have to connect the many cells together by means of Nickel strips or thick wire. Generally, Nickel strips are widely used for this. In general two types of nickel, strips are available in the market: nickel-plated steel strips and pure nickel strips. I will suggest buying a pure nickel. It is a little bit costlier than nickel-plated steel, but it has much lower resistance. Low resistance means, less heat generation during the charging and discharging, which leads to longer useful battery life.
Nickel strips come with different dimensions and lengths.
Result :-
| NO | Calculated Parameters | Value Get |
| 1 |
Cell Volume |
0.0000344929m^2 |
| 2 | Cell Energy | 8.25Wh |
| 3 | Cell Density | 239179.6572kWh/m^2 |
| 4 | Pack assumptions | 50s 44p |
| 5 | Total no of cells | 2200 |
| 6 | Voltage | 165V |
| 7 | Capacity | 110Ah |
| 8 | Energy | 18150WAh |
| 9 | Total volume | 0.07588m^2 |
| 10 | Total Density | 1377.30kWh/m^2 |
| 11 | Weight | 167.2kg |