Project 1 Mechanical design of battery pack

AIM :

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

PROCEDURE :

The detailed battery pack of ANR26650M1-B

Battery parameters, specifications and dimensitions.

For the calculation of the volume of the cell we use the formula of Volume of cylinder. To find out the total volume of the battery pack. find volume of the cell.

As per barrety dimensions r=0.013m and h=0.065m

* volume of cell = Pi*r^2*h

= 3.14*0.01362*0.065

= 0.0000344929 m^3

* Cell Energy = Cell Capacity (Ah) × Cell Voltage (V)

= 2.5 × 3.3

= 8.25 Wh

* Volumetric energy (Wh/m³) = Single Cell Energy / Volume of each cell

= 8.25 Wh / 0.0000344929m³

=2,39,179.6572 Wh/m³

BATTERY PACK CALCULATIONS :

Now we calculated parallel and series combinations so we can now calculate total no of cells required

Assuming the capcity of battery pack is 18000 wh

Assuming the voltage 165 V then

no.of cells required in series = toatl voltage of battery pack / Voltage of battery cell

= 165v / 3.3v

= 50 cells

no.of cells required in parallel = total current of battery pack / capacity of each cell

= 110 Ah/ 2.5 Ah

= 44 cells

Total no of cells: Series cells * parallel cells

:50*44

: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

= 165 V

* Current = No of parallel cells * cell capacity

= 44*2.5

=110 Ah

* Energy = Voltage * Current

= 165 * 110

= 18150 WAh

calculating the total volume required for battery pack

* Total volume = no of cells * Volume of single cell

= 2200 * 0.0000344929

=0.07588438 m^3

calculating 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

* Energy dencity = volume * battery pack energy

= 0.07588438 * 18150

= 1,377.301497kWh/m^3

BATTERY PACK ENCLOUSURE :

Arrangement of battery cells in series and parallel combinations. There are so many ways to connect the cells in series and parallel that arrangement is based on space.

Cell holders are used to hold the battery cells. The holders fitted in top and bottom side of a battery cells. Now the cells are in fixed position.

For connecting the each battery cell we need to metal strips. Generally the metal strips are made of copper, steel, nickel and in sometime times the strips are may mixture of all metal layers. Different automanufactures are using different methods of connecting battery cells to optimize the overall parameters of battery pack.

After the connections are done the modules are get placed in enclosure and no.of modules are made a complete battery pack.

The above figure shows the complete process of battery pack.

CONCLUSION :

Hence the battery pack is drawn with its enclosure.