Project 1 Mechanical design of battery pack

Introduction:

At First conventional vehicles are slowly decreasing sales due to the some disadvantages pollution,Efficiency,torque.

Electric vehicles are growing because of no pollution and efficiency.We have n number of battery combinations In that Lithum ion Battery are best upon Efficiency,power,Energy compared to other Battries.

Lithum Ion battery is rechargable Battery.For every cell we have anode and cathode.Anode is Graphite and cathode is metal oxide.During Discharge Lithum Ions move from anode to cathode. when charging Lithum Ions move from cathode to Anode.

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:

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

TRANSPORTATION SOLUTIONS:

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

• Commercial vehicles
• Off-highway vehicles
• Passenger vehicles

As from above graph constant power discharge and constant current discharge at various Temperatures.

This Graph Shows that performance of battery at different cycles.

Technical Data of battery from Data sheet:

Battery Calculations:

Assumptions:

Battery Energy = 28KWh

Voltage to run vehicle = 400V

1)Energy = 18KWh

2)Number of cells = energy/(Nominal Voltage*capacity)

(energy converting from KWh to Wh

Energy = 18*1000 => 18000Wh)

Number of cells = 18000/(3.3*2.5)

Number of cells = 2182

By above calculations says that we required 2182 cells

3) To find Series and Parallel configuration:

For series configuration capacity remains same and voltage can be Increased depends upon how many cells we used.

As shown in above figure voltage is increased form 3.6 to 7.2 because 2 cells connected in series.capacity(3400mAh) is constant.

For parallel configuration voltage remains constant and capacity can increase depends on how many cells we used.

As shown in above figure voltage is constant to 3.6V.Capacity(current) is increased form 3400mAh to 13600mAh(3400*4).

Nominal voltage given in datasheet as 3.3V

Number of cells in series = Total Voltage/Nominal Voltage

Ns = 400V/3.3V

Ns = 121

By above calculation says that we required 121 cells that has to connected in series.

Number of cells in parallel = Total cells/Number of series

Np = 2182/121

Np = 18

As from the above calculations we require 18 cells in parallel

so,we required this configuration 121S18P

Battery Capacity:

Here I am taking 18 because of parallel config.As from data sheet 18*2.5 = 45Ah capacity of Battery.

Joining Technologies for a Lithium Ion Battries:

Ultrasonic Welding:

Ultrasonic metal welding (UMW) is one of the most commonly used joining methods for battery systems manufacturing and

has been applied to a wide range of metals and thin metal films (e.g., foils). It utilises high frequency ultrasonic vibration,

typically 20 kHz or above, to join substrate materials by creating solid-state bonds under a clamping pressure.

Spot Welding:

Spot welding (or resistance spot welding) is a type of electric resistance welding used to weld various sheet metal products,

through a process in which contacting metal surface points are joined by the heat obtained from resistance to electric current.

Cell Holder:

A cell holder means that cells can fix one which the cells cannot move.external connectors of the holders can fix with wire,pins.As from below Image black can called as cell holder.

Packing Cells:

When we comes to the packing of battery safety comes first without any disruptions which can transfer and recieve energy.

Battery Dimensions:

Length = 2730mm

Breadth = 18*(30)+60 => 600mm

Height = 100mm

Weight:

For each cell is 76g. so total 2182*76+4.5 => 170Kg

This much weight Requires for Battery Pack.

Result:

This is the Process to design Mechanical Model of Battery Pack.