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title: OLD COURSE DOCUMENT

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# OLD COURSE DOCUMENT

### CHAPTER 1

### CHASSIS DESIGN AND ANALYSIS

### 1.1 OBJECTIVES
This chapter will enhance the electric bicycle chassis which acts as a backbone and carries a maximum load in an operating condition. We will learn about the parameters while designing bicycle chassis which includes material selection, design consideration, and analysis. And also, we will learn various engineering tools used in the processes.
### 1.2 INTRODUCTION
The chassis is considered as the most significant component of a vehicle that gives strength and stability to the vehicle under different conditions. It is designed in such a way that it will satisfy various factors like stability, rigidity, safety, and durability.

### 1.3 DESIGN OF CHASSIS
### 1.31 Material selection
There are mainly four types of material considered for frame designs: 
Steel, aluminium, titanium and carbon fiber depending upon application and costing.
Steel
It is the most traditional frame material used over a century, usually, steel tubes are used which are readily available and easy to bend to required shapes. It also offers excellent ride quality, durability, which can be easily repaired and affordable. It also absorbs shock to soften rough roads. Popular quality steel for bicycle frames is American SAE 4130 steel, better known as "chrome molybdenum.
Aluminium
It is known for being corrosion resistant, fairy light and having a high strength-to-weight ratio. It’s also typically stiff and responsive, making it good for criterium racing bikes because it accelerates quickly and delivers a light handling. The downside is that stiffness often means a harsher ride quality because it doesn’t absorb road shocks as well as the other frame materials.It’s also tricky to repair, and aluminum fatigues more quickly over time
Titanium
The titanium similar properties of steel, but has a greater resistance to corrosion and fatigue with the highest strength-to-weight ratio of all metals. That means you can build long-lasting, lightweight frames. Titanium is also renowned for its smooth ride quality making it an especially popular choice for custom road, touring, and hardtail mountain bikes.The downside is that titanium is relatively rare thus making it expensive material.
Carbon fiber
It is the most commonly used frame material for higher-end mountain and road bikes. Carbon fiber is a composite of carbon sheets that are bonded together in a mold using resin. The primary advantage of the material is that at a given stiffness, carbon fiber is significantly lighter than aluminum, steel, or titanium.This lower density also means carbon frames do a better job of absorbing road vibration, which translates into a more comfortable ride. And carbon fiber can be formed into complex shapes, giving bike makers greater creative design latitude. This is especially useful when trying to maximize the aerodynamic efficiency of a frame.carbon fiber bikes are typically the most expensive. These frames are also more prone to fracture than metal, and once that happens carbon becomes fragile, and thus unfit to ride.

### 1.32 Design consideration
There are several design parameters that need to be followed in various standards based on the safety and maneuverability of the bicycle. Understanding the bicycle frame geometry is very important while designing.
 

Understanding the steering
It includes three measurements: Headtube angle, fork rake(offset) and Fork trail
Head tube angle
It is an angle made by the head tube with respect to the ground. Let us consider these scenarios for better understanding:
A bike with a steeper head angle has faster steering. There is less effort required to steer it.
A bike with a slacker head angle has slower steering. There is more effort required to steer it.
Fork angle offset
Fork rake is the offset of the fork dropout from the straight line of the steering axis.
Increasing the fork rake makes steering faster.
Decreasing the fork rake makes steering slower.

Fork trail
 

The product of the head tube angle and the fork rake is the ‘trail’. This is the measurement that gives us the best indication of how fast a bike will steer.
Less trail equates to faster steering. 
More trail equates to slower steering. 
Chain stay length
It is an important measurement in touring bikes. A longer chainstay length is desirable to increase the wheelbase making the bike more stable at speed and to provide ample wheel clearance from the panniers.

Wheelbase
A longer wheelbase provides a more stable at high speeds and comfortable ride.

Bottom bracket drop
The bottom bracket drop determines how high your cranks sit from the ground when you pedal. A lower bottom bracket results in lower saddle height and therefore a lower center of gravity.

Seat tube angle:It is an angle made by the seat tube with respect to the wheel baseline.

Effective tube length: The effective top tube length is the simplest way to determine a bike’s size.

Seat tube length:  It is a length of the seat tube that decides the height of the seat in a bicycle.

Head tube length:  This length depends on what type of bicycle, whether it’s a road bike, touring or off-road. In the headtube fork of bike usually houses with thrust bearing assembly.

### 1.4 BIKE FRAME TERMINOLOGY

 

The geometry of the frame governs the properties and performance of the bicycle. The lengths and angles of the frame affect a rider’s riding comfort and behavior.
1.5 CAD MODELLING OF CHASSIS
The computer-aided (CAD) system is the use of computer software to help in creating, analysis, modifications or optimizing a design.CAD uses drawings in 2D and 3D space to generate an output in the form of electronic files for printing, matching or other manufacturing operations. In mechanical engineering, CAD modelling can be used for 2D drawings or 3D modeling of components from the conceptual design to the assembling of these components.

1.6 FUNDAMENTALS OF FINITE ELEMENT ANALYSIS
 The purpose of this topic is to analyze the stress on bicycle frames and optimize their design using analysis software like Ansys to establish numerical simulations of the bicycle frame, stress analysis and optimal designs of the frame structure.
The modeling for the frame started with the development of several concepts for the performance of the frame. Once the concept was selected it is designed using respective design software. 
The material property and geometry of the frame play a very important role in the analysis. For example, these are the basic material property and dimensions that need to be considered before the analysis.
 
 
Theoretical analysis of bike frames 
The modelled bicycle frame is made to apply with the following load cases as a part of the analysis of the frame. The load cases are applied to all the 5 frames individually.
 The load cases are namely: 
1) Static start-up. 
2) Steady-state pedalling. 
3) Vertical impact. 
4) Horizontal impact. 
5) Rear-wheel braking.

Steps in Ansys analysis
Static structural: Static analysis is used to determine the displacements, stresses, strains, and forces in structures or components caused by loads that do not induce significant inertia and damping effects. These loads vary slowly in magnitude because the acceleration of load is very less compared to the natural frequency of the structure.
Material selection: The material is selected as per requirement by looking into various properties that are already defined in the software.
Import the geometry: The frame which is designed in design software is imported into Ansys by using import option under static structural.
Modelling:
Setting the Material for each part: Using the energy data module required material is assigned to the material.
Meshing:
Support constraints:
Force constraints:
Solution:
Solving:
FRAME FABRICATION
Once you have an accurate drawing of the bike, it is time to start cutting your tubing into the required dimensions. Notches are done on tubes so that they are easily fit while joining. These notches are done by using Tube miteringprocess which can be done a variety of ways and the simpler method is with a milling machine. Notches are made at the right angles based on your design.
The next thing is to welding chainstays. Dropouts simply slip over the ends of the stays so that they can be welded
To do this, measure the inside diameter of the chainstay and modify the dropout to fit as shown in the figure. The slots need to be angled slightly. This angle can come from yourdrawing. The chainstay angle inward from the dropouts to the bracket shell. Once you have the stays slotted and the dropouts tabbed it is time to weld them in. To make sure everything is aligned and accurate, it is best to use a fixture to hold the stays and dropouts while you weld. 
The first major joint to weld is the bottom bracket and seat tube joint Make the seat tube is lined up in the center of the bracket shell and perpendicular to it using a jig and weld it.  The remaining tubes are welded as per notch in the drawing. Once all joints are tacked you can remove the front triangle from the jig and get ready to fully braze (or weld) the joints. After finishing welding cleaning up all your joints. Get all the flux off the frame by submerging it in a solution bath and get it painted.


### CHAPTER 2

BICYCLE COMPONENTS
2.1 OBJECTIVES
This chapter will understand the basic components of the bicycle and its role in a bicycle.
Brakes
Brakes are used to control the speed of the bicycle and also bring it to a complete halt, so high quality working brakes are vital for safety. There are four types of brakes; V-Brake, Cantilever, Calliper and Disk brakes. V-Brakes and Cantilever brakes are commonly used on commuter, trail and entry-level mountain bikes. Caliper Brakes are popular on road bikes. Disk brakes are most often used on Mountain Bikes but are now starting to appear on Road Bikes too. 
 
Forks
Bike forks hold the front wheel in place on your bike. Extending from the headset of your bike to the hub of the wheel, they are usually made up of two tubes held together by the crown, and the steerer section allows you to turn the wheels and steer the bike. Forks come with or without suspensions based on the requirement, but the suspension is always preferred with absorbs shocks on road.
 
Chainset
The chainset of a bike includes the cranks, bottom bracket, and chainring. These components drive the bike forward. There are many different options when it comes to chainsets like geared or not geared.
 
Handlebars
Handlebars allow you to steer the bike, so it’s important that they provide you with required control over the bicycle. The shape of the handlebars is based on the type of bicycle and its application. For example:
Road bikes typically use narrow drop bars to provide better aerodynamic positioning on the bike when descending.
Commuter bikes have flat handlebars for a more upright position on the bike giving better visibility of the road ahead.
 
Mountain bikes use wide riser handlebars to assist control around tight bends and over obstacles.
The weight of a bike can be further reduced by using carbon handlebars.
Stems
The stem attaches the handlebars to the bike. Stems come in different lengths and rise so it can be adjusted to the required riding position that suits the user. In general, a shorter stem will give you quicker, more responsive steering but tends to be a less aerodynamic body position, whereas a longer stem gives you a more stretched out and aerodynamic position on the bike.
 
Wheelset
A wheelset of a bike consists of rim and tire. Bike rims are made from a range of materials including steel, stainless steel, aluminum, titanium, and carbon. The selection of rim plays an effective way of upgrading your bike, making it lighter, faster and more responsive.
 
### CHAPTER 3
3.1: ELECTRIC MOTOR
An Electric Motor is an electrical machine that converts electrical energy into mechanical energy.The principle behind the working of an electric motor is when a current-carrying conductor is placed in a magnetic field it experiences a magnetic field and starts rotating according to the direction given by Fleming’s Left-Hand Rule for a motor. 
There are many types of electric motor available in the market and the choice of these motors are very important. Selection of these motors is based on voltage, operation, and application.
3.2: TYPES
Motors are classified based on the power type that is AC or DC and their method for generating rotation.
DC MOTORS
•	Brushed DC motor
•	Brushless DC motor
•	Stepper Motor
AC MOTORS
•	Induction Motor
•	Stepper Motor
Both types of motor have their own advantages and disadvantages:
 

3.3: IMPORTANT PARTS OF AN ELECTRIC MOTOR
•	Armature
•	Commutator
•	Brushes
 
Figure10: Important parts of an Electric Motor

Armature: It is the power generating part in an electric motor. It can be a rotating part or the stationary part of the machine.  The armature [ABCD] has the rectangular iron core wrapped by copper wire through which current is passed and is placed between the two poles of a magnet. The armature has an axle to which commutator is attached.
Commutator: They are the split rings which reverses the direction of the current. They connect the brushes and coil and are made up of copper. The purpose of the commutator is to make sure that the current direction in the coil reverses every half time so that one side of the coil is pushed downwards and another side of the coil is pushed upwards. The contacts of the commutator are linked to the axle of the armature so they rotate with the coil.  In the above figure, commutator rings are denoted as C1 and C2.
Brushes: They are the two pieces of metal or carbon. One end of the brush is connected to the commutator and other ends of the brushes are connected to the positive and negative terminal of the battery respectively. In the above figure, Brushes are denoted as B1 and B2.


3.4: WORKING OF AN ELECTRIC MOTOR
An electric motor uses the magnetic push to rotate the current-carrying conductor. Magnets S and N [Fig 4.3] will generate the magnetic field that will rotate the current-carrying conductor. Instead of inserting the current-carrying wire, a current-carrying loop [rectangular loop] is introduced as in the figure. Each side of the coil will experience the force and hence the coil starts rotating. To find the direction of the force in each side of the loop Flemings Left-Hand rule for motors(also called motor rule) is used.
Fleming’s Left-Hand Rule:
 
Figure11:Fleming’s Left Hand Rule
Hold your thumb, fore and center finger of your left hand such that three fingers are at right angles to each other.
If you point the center finger in the direction of the current and the forefinger in the direction of the field, your thumb will show the direction of motion.
•	Fore-finger = Field
•	Center finger = Current
•	Thumb finger= Motion
 
Fig 12: Working of an Electric Motor
To begin with, the plane of the rectangular coil ABCD is made parallel to the magnetic field by placing the coil in the horizontal position. Electric current is passed through the rectangular coil ABCD, which enters at A and leaves at D as shown in the figure. When the current is passed AB and CD side of the coil which is perpendicular to the direction of the magnetic field experience force according to Fleming’s left-hand rule. As the current passing through AB and CD of the coil are in the opposite direction, the forces acting on them will also be opposite. Hence forces push AB in downward direction and CD in the upward direction. Thus, the coil starts rotating in the anticlockwise direction.
The commutator rings C1 and C2 change their contact from brushes B1 and B2 respectively when the coil completes its half rotation. Because of this, the direction of current in the rectangular coil ABCD is reversed, due to which the direction of forces in the coil is also reversed. Hence side AB is now pushed in upward and CD in the downward direction. Similarly, the whole process is repeated for the continuous rotation of the coil.

3.5: SELECTING A SUITABLE MOTOR RATING FOR THE                   APPLICATION
For our application we are using Brush Less DC Motor
Also known as BLDC motor or BL motor, it is the DC motor which does not have brushes. Motor is the heart of an Electric Vehicle. It is called Brushless because it doesn’t have brushes and commutator arrangements. Here the commutation is done electronically.
3.5.1: PRINCIPLE OF BLDC MOTOR:
The working principle of BLDC motor is similar to Brushed DC motor. The reversal of current in Brushed DC motor is done by Commutator and Brushes whereas in BLDC motor sensors are used, mostly hall-effect sensors. The hall-effect sensors generate a high or low signal whenever rotor magnetic poles cross the hall sensors, which can be used to detect the position of the shaft.
3.5.2: TYPES OF BLDC MOTORS:
They are classified based on designing and their working procedure is the same.
•	Outer rotor design
•	Inner rotor design
 
Figure 8: BLDC Motor Types

OUTER ROTOR DESIGN: The rotor of the motor is situated outside and it surrounds the stator which is located in the center of the motor has multi-phase winding. The windings are fed with current and are controlled(commutated) to effect rotation of the rotor. There is no need of external gear system in this type of design and in few instances the motor itself comes with inbuilt gears. Therefore, without any gear system this design makes the device less bulky.  The magnets present in the rotor acts as an insulator and will not allow the heat to dissipate from the motor. Outer rotor designed motor has low torque and operated at low current rates.
INNER ROTOR DESIGN: As in the image the rotor is situated in the centre of the motor and is surrounded by the stator winding. The rotor magnet does not shield the heat inside and the heat will be dissipated effortlessly, thus increasing the torque.

3.5.3: WORKING OF BLDC MOTOR
 
Figure9: Working of BLDC Motor
The BLDC motor has 2 main parts rotor and stator. The rotor is the permanent magnet and is rotating part. The stator is the armature winding and is the stationary part. In BLDC motor coils do not rotate as in Brushed DC motor instead they are fixed onto the stator. There is no need of commutator and brushes since coils are static.Mechanical rotation is produced when the magnetic field generated by the permanent magnets(rotor) comes in contact with the field induced by the current in the stator windings. The magnitude and direction of the current into the coils are adjusted to control the rotation.
 Hall effect sensors are mounted on the stator or rotor. As the rotor rotates the hall effect sensors senses the magnetic field and produces a high signal for one pole or low signal for opposite pole. These sensors are connected to the Electronic control unit. Electronic control unit switches the supply voltage between the stator winding as the rotor rotates and energize the correct winding at correct time in such a way that it rotates the rotor around the stator. According to these combinations of signals electronic unit will decide the next commutation sequence or interval to activate.
Some of the advantages of Brushless DC motors are they are highly efficient, exceptional controllability, produce high torque, higher speed range compared to other motors, Operating life is long due to absence of electrical friction losses, Operation is noise-less, high dynamic response. It has power-saving advantages also. Due to its traction characteristics they are most preferred motors in electric vehicle applications.














CHAPTER 4
For 36V motor we need 36V Battery Pack, Now let’s understand about Battery, its Terminologies, battery pack and BMS. 
4.1: BATTERY
Battery is a device which is used to store the chemical energy and to convert this chemical energy into electrical energy.  The battery is made up of electrochemical cells, which consists of two electrodes, negative and positive electrode and an electrolyte in the center. When the two electrodes are connected by a wire, electrons will flow from negative electrode to positive electrode. This flow of electrons is called electricity. The cell is considered to be dead when the electrons on the positive and negative electrodes are equal. The electrons are generated by chemical reactions and many different chemical reactions are used in batteries.
4.2: BATTERY DEFINITIONS AND TERMINOLOGIES
Cell - An electrochemical device, composed of positive and negative plates and electrolyte, which is capable of storing electrical energy. It is the basic “building block” of a battery.
Capacity - The capacity of a battery is a measure of the amount of energy that it can deliver in a single discharge. Battery capacity is normally listed as amp-hours (or milli amp-hours) or as watt-hours.
Direct Current (DC) - The type of electrical current that a battery can supply. One terminal is always positive and another is always negative.
Cycle - One sequence of charge and discharge.
Charge - The conversion of electric energy, provided in the form of a current, into chemical energy within the cell or battery.
Discharge - The conversion of the chemical energy of the battery into electric energy.
Battery-Charge Rate - The current expressed in amperes (A) or milli amps (mA) at which a battery s charged.
Ampere:  An Ampere or an Amp is a unit of measurement for an electrical current. One amp is the amount of current produced by an electromotive force of one volt acting through the resistance of one ohm.
Ampere-Hour: A unit of measurement of a battery's electrical storage capacity. Current multiplied by time in hours equals ampere-hours. One ampere hour is equal to a current of one ampere flowing for one hour. Also, 1 ampere-hour is equal to 1,000 mAh.
Volt - The unit of measurement of electromotive force, or difference of potential, which will cause a current of one ampere to flow through a resistance of one ohm.
Watt - A measurement of total power. It is amperes multiplied by volts. 
Watt-Hour:A Watt Hour is a unit of measurement for power over a period of time. One watt-hour is equal to one Watt of average power flow over an hour. One Watt over two hours would be two Watt-Hours of power.
Cycle Life - For rechargeable batteries, the total number of charge/discharges cycles the cell can sustain before its capacity is significantly reduced. End of life is usually considered to be reached when the cell or battery delivers only 80% of rated ampere- hour capacity. The cycle of a battery is greatly influenced by the type depth of the cycle (deep or shallow) and the method of recharging. Improper charge cycle cut-off can greatly reduce the cycle life of a battery.
Depth of Discharge - The amount of energy that has been removed from a battery (or battery pack). Usually expressed as a percentage of the total capacity of the battery. For example, 80% DOD means that eighty percent of the energy has been discharged, so the battery now holds only 20% of its full charge.
Energy Density:The volumetric energy storage density of a battery, expressed in Watt-hours per litre (Wh/l).
Power Density:The volumetric power density of a battery, expressed in Watts per litre (W/l).

State of Charge [SOC]: SOC refers to the remaining charge in a cell as a percentage of the charge contained by the cell when it is full.  We cannot accurately determine the charge remaining in the cell without fully discharging it first, so the calculation for SOC is usually performed by subtracting the charge removed from the cell so far from the charge contained when it was last charged to 100% SOC.
 

State of Health [SOH]:  The change in the amount of charge that the cells can hold as they age. In case of Electric Vehicle, the capacity of the cells in the battery pack is the important parameter in determining the range which can be achieved in one charge.
Hence State of Health of an Electric Vehicle battery pack, that is SOHe, which is the amount of charge the cells in the battery pack can hold as they age.
 
Over a succeeding number of cycles of cells, the capacity of a lithium-ion cell will drop owing to a number of factors including loss of lithium inventory and failing of the electrodes inside the cell. Hence when an aged cell is charged and discharged to its maximum and minimum voltage values respectively, the charge obtained will be lower than charge obtained when the cell was new.

4.3: BATTERY TYPES
The types of rechargeable batteries used in Hybrid Electric Vehicles and All-Electric Vehicles [EV] are 
•	Lead-Acid battery.
•	Nickel-Cadmium Battery (NiCd or NiCad)
•	Nickel Metal Hydride [NiMH] battery.
•	Lithium-ion [Li-ion] battery.
Each battery type has its own advantages and disadvantages, and selection of these batteries depends on where it is used so that maximum benefit can be obtained.

4.4: LITHIUM ION BATTERY
NiMH and Li-ion came into view in 1990s and Li-ion became the most promising and the fastest growing battery system. Lithium offers the largest energy density and is the lightest of all the metals. Due to safety issues attempts to develop Lithium-rechargeable batteries failed. Thus, there was a shift from Lithium to Lithium-ion, it is safer but lower energy density than Lithium metal. The Sony Corporation in 1991 commercialized the first Lithium-ion battery. The electrodes are made of lightweight lithium and carbon. The Lithium-ion has energy density twice that of Ni-Cad Batteries.
One of the reasons for the rapid growth in the development of Li-ion batteries is a huge acceptance of these batteries in cell phones, laptops, and computers. Out of all battery types Li-ion provides the highest density and thus electronic manufacturers prefer these over other battery technologies. The applications are categorized into automotive, medical, aerospace, military,consumer electronics and so on. They are also used in renewable energy areas for energy storage purposes. Other advantages such as long lifespan, low self-discharge, high charge, and discharge cycles have added to the growth of lithium-ion battery market.
The subclass of the lithium-ion battery market is Lithium-Iron-Phosphate [LiFePO4], Lithium-Nickel-Manganese-Cobalt-Oxide [NMC], Lithium-Manganese-Oxide [LMO], Lithium-Nickel-Cobalt-Aluminium-Oxide [NCA], and Lithium-Cobalt-Oxide [LCO] batteries.
3.6V 2400mAh Lithium-Ion battery has Typical end-of-discharge of 2.8V - 3V and Maximum charge voltage of 4.2V. 3.2V 6000mAh LiFePO4 can be charged up to 3.7V
4.5: SERIES AND PARALLEL CONNECTION OF BATTERY
Therequired operating voltage and current for any application is got by connecting number of cells in series and parallel connection. 

 
Figure 5: Series Connection
In series connection each cell adds its voltage potential keeping the same amperage rating [Amp-Hours]. For instance, two 3.6V 2400mAh batteries connected in series[2s] produces 7.2V and capacity of 2400mAh.
 
Figure 6: Parallel Connection 
In parallel connection increases the current rating keeping the same voltage rating.
For instance, two 3.6V 2400mAh batteries connected in parallel[2p] produces 3.6V and capacity of 4800mAh.
 
Figure 7: Combination of Series and Parallel Connection
Some battery packs consistof a combination of series and parallel connections as per the application requirement. For instance, to satisfy the requirement 7.2V and 4800mAh, cells must be connected in 2s2p format where each cell value is 3.6V 2400mah, meaning 2 cells in series [7.2V] and 2 cells in parallel[4800mah].

It is important to use the same battery type with equal voltage and capacity (Ah) and never to mix different battery type and sizes. A weaker cell in the pack will cause an imbalance. A weak cell may not fail immediately but will get drained rapidly than the strong ones when on a load.

4.6: BATTERY PACK
A battery pack is a set of any number of identical individual battery cells. They may be configured in a series, parallel or combination of both to produce the desired voltage, capacity, or power density.
4.6.1: 36V BATTERY PACK
For 36V battery pack ten 3.6V 2400mah batteries are connected in series. 
REFER VIDEO: https://www.youtube.com/watch?v=b3eRv_FZjBc
4.6.2: SPOT WELDING
Building battery packs involve welding thin Nickel strips from one battery cell to another with a spot welder. The first pulse heats the weld surface to remove contaminants and to seat the welding electrode tips. The second pulse then performs a strong spot weld.
Hence series connection is made as in the figure using spot welding.
[Image to be added]
WARNING: Wear safety glasses and protective gloves when working around a battery.
REFER VIDEO: https://www.youtube.com/watch?v=ublFs7IU05c
4.7: BMS
BMS is the brain of the electric vehicle. It controls the charging and discharging of the battery by determining how fast and how much electricity should flow through the battery. It shields the battery from working outside its safe operating range. Each model will have an exclusive BMS.
4.7.1: BMS FUNCTION
Some of the functions of BMS are
•	Monitoring the conditions of individual cells which make up the battery.
•	Maintaining all the cells within their operating limits
•	Protecting the cells from out of tolerance conditions
•	Isolating the battery in cases of emergency
•	Compensating for any imbalances in cell parameters within the battery chain
•	Setting the battery operating point to allow regenerative braking charges to be absorbed without overcharging the battery.
•	Providing information on the State of Charge (SOC) of the battery. 
•	Providing information on the State of Health (SOH) of the battery. This measurement gives an indication of the condition of a used battery relative to a new battery.
•	Predicting the range possible with the remaining charge in the battery 
•	Providing the optimum charging algorithm for charging the cells
•	Responding to changes in the vehicle operating mode
	
4.7.2: WIRINGBMS TO BATTERY PACK
Parameters to be considered when working with BMS:
•	Voltage: The number of cells in the battery connected in series. For instance, 7 cells of 3.6V in series produces 36V. Hence 36V BMS should be considered.
•	BMS Current Rating: BMS is rated with different values of current ranging from low power BMS to high power BMS. According to the load current rating requirement BMS is selected. I
In our application 36V 10A BMS is used, which matches our load requirement[load=10A]
Therefore, Number of Cells and max power Rating[current] are the two important factors which should be considered.
WIRING BMS:
We are considering 36V 10A BMS. 
[BMS IMAGE TO BE ADDED]





Three main connections
 
Figure 11: BMS Connection
[Image to be changes]
•	C- [C minus] : This port is the charger connector. The negative of the charger wire is connected to this port. Positive of the charger is connected to the positive of the battery pack.
•	B- [Battery minus] : The first set of the battery pack[negative end] is connected to this port.
•	P- [Pack minus]: Discharge Connector, which is connected to the Battery pack minus. 
 

https://www.youtube.com/watch?v=u-4mKh1WaLo	


4.7: INSULATION
Proper insulation of a battery pack is important to shield the battery from high and low temperatures respectively. These extreme temperatures can shorten the lifespan of the battery. Battery insulation options consist of insulation wrap and a battery box designed to withstand extreme heat and cold.
Barley Paper is used for insulation in this application. Barley paper provides high insulation, shielding and anti-interference.Proper maintenance of a battery extends its life and prevents the battery from failing.
Next step is sealing the battery pack. Common methods of sealing the battery packs are using heat shrink wraps or putting the battery pack in some hardcase.
REFER VIDEO: https://www.youtube.com/watch?v=ALshbpGkMtc
	After the insulation connect the free endsusing  XT60or XT90 connectors according to the application.
4.8: CHOOSING THE CORRECT CHARGER FOR THE BATTERY PACK
The two important factors that must be considered while choosing the right charger for the battery pack
•	Voltage: It is the number of cells in series multiplied with the maximum voltage [fully charged cell]. 
For instance, consider ten 3.6V 2.4Ah Lithium-ion cell, which can charge up to 4.2V. 
Voltage= 10x4.2=42V. Hence charger which outputs 42V is selected.
•	Charge Current: Select the charger with current less than the BMS maximum charge current.
For instance, if maximum charge current of BMS is10Amps, then select the charger which is within 10A. Hence a 5A charger can be used.
Other factor is quality of the charger, such as plastic charger, aluminium case charger, adjustable voltage charger with cooling fans and the cycle Satiator.





CHAPTER 5
For 36V motor 36V controller
5.1:MOTORCONTROLLER
Motor Controller is a device that is used to improve performance of an electric motor in a programmed manner. They are the drivers which controls different aspects of the motor to ensure the right current and voltage is applied across the motor. Motor controller can include an automatic means for starting or stopping the motor, controlling the speed, limiting the torque, and shielding against overloads, varying and specifying factors such as speed, direction, voltage, and braking.  Motor controller is employed to regulate the torque generated by the motors of electric vehicles by means of modifying the energy flow from the power sources to the motor.
There are different types of motors, each having different driving methods and different power rating. As power ratings increase, the complexity of the motor driving mechanism increases.

5.2: 36V CONTROLLER
	In this application 36V controller is used
 

CHAPTER 6
ASSEMBLY
Installing Hub motor to Rim
Battery connection
Controller connection
•	Brakes
•	Battery
•	motor
•	Throttle














REFERENCES:
i.	http://www.greenbatteries.com/glossary-of-battery-terms-1/
ii.	https://www.dataweek.co.za/59316n




