The document proposes a design for an improved electric bike that uses a hybrid energy storage system combining a lithium iron phosphate battery pack with a supercapacitor bank. This hybrid system aims to overcome the limitations of current e-bike designs such as long charging times and short battery lifespan. Specifically, the supercapacitors would provide high currents for starting and acceleration to reduce stress on the batteries and increase their lifespan, while regenerative braking and a small onboard solar panel could provide secondary charging sources. The proposed design uses more efficient and eco-friendly lithium iron phosphate batteries that have a longer life and faster charging time compared to lead-acid batteries typically used in e-bikes.

1. Guided By: Presented By:
Ms. LALLUMOL MATHEW JOSEPH
Asst.Professor S7 EEE , 21
Department of EEE REG NO: 13018818

2.  Introduction
 Objectives
 Merits of present E-bikes
 Demerits of present E-bikes
 Proposed design
 Salient features
 Solutions to overcome drawbacks
 Requirements of the system
 Conclusion
 Reference

3.  Currently, electric vehicle are getting popular.
 The main drawback is the long charging time of 6-8 hrs and short
lifespan of battery pack i.e. around 2 years.
 Considering these limitations ,several modifications are being done in
the existing design .
 It will give a better performance with the use of a hybrid system of
battery and super capacitor.

4.  Super-capacitor modules are used to provide the high current required
during starting and acceleration, and eventfully will help increasing
lifespan of battery.
 A secondary source, like regenerative braking or a small solar panel
module could be availed onboard so as to charge battery/ super capacitor.
 Super-capacitors along with battery provides a hybrid energy source for
an electric bike.
.

5. .
Good efficiency
 IC engines are 40% efficient whereas BLDC (Brushless DC) motors
equipped in e-bikes are above 90% efficient in power utilization.
Eco-friendly
 If the electric power required to charge the batteries is derived from non
conventional sources, then electric vehicles are very environment friendly.
Cheaper and Quieter Journey
 Due to good efficiency, electric units required is too less. Electric vehicles are
the quietest of all means of transport.

6. Lower speed
 E-bikes don’t attend the higher speeds which petrol or Diesel powered vehicles
easily do.
Longer charging time
 The batteries require about 6-8 hours of charging time.
Battery issues
 Especially lead acid batteries degrade heavily over time. So a bike with lead acid
batteries will require replacement after about 2-3 years.
 The decomposition of batteries is not eco-friendly.
.

7.  The bike will have 2kW 48V geared BLDC rear wheel hub motor, driven by a 48V
40Ah battery pack.
 The super-capacitor bank consist of a 16V, 58F to be connected in parallel with the
battery pack .
 Microcontroller circuitry senses various parameters and performs switching and
controlling action.
 The controller is the heart of E-Bike .
 Throttle is a potentiometer box which acts as an accelerator

9.  Hybrid energy storage system
 A parallel combination of battery and super-capacitor is involved.
 Super-capacitors do not have a dielectric material to separate the
electrodes , instead a physical barrier made of activated carbon.
 The surface area of the activated carbon is large thus allowing for the
absorption of large amount of ions.

10.  A small solar panel is mounted on the bike taking the aerodynamics of
the bike into consideration.
 The regenerative braking acts as another power sources too.
 The secondary source will be used to charge battery, which then will
charge the super-capacitor bank and power the accessories.

11.  The proposed design involves use of Lithium iron
phosphate(LiFePO4) batteries.
 They are lighter and eco-friendlier than lead acid.
 They have better life of about 7-12 years.
 LiFePO4 batteries also have lesser charging time of 4-6 hrs which is
quite better than 6-8 hrs of lead acid.

12.  The accelerator is a 5V potentiometer varied from 5V to 0V.
 Super capacitors and batteries will be in circuit providing power to
motor.
 If the super capacitor’s state of charge sinks below 8V, then super
capacitors will get detached from the circuit and will start charging
from auxiliary battery.
 There will be a switch along with the brakes which will engage
regenerative breaking as the bike starts de-accelerating.

14. High Power Density and High Current Capability
• Very High Efficiency
• Less Charging Time
• Long Life Cycle
• Low Impedance
• Simple Charging Methods
• Wide Temperature Range
The only disadvantage of super capacitors is they discharge quickly and
should not be subjected to overvoltage.

15. For low speed
 Super capacitor bank is especially used to provide the heavy initial
starting current.
 Super capacitors not only provide the required boost but also relieve
battery from stress of huge currents, thus improving the battery life.
 Super-capacitors are also used with a switch in a boost mode when
higher speed is required.

16.  The proposed model involves regenerative and secondary power
source like a small solar cell module.
 The charging time can be reduced due to LiFePO4 and the range can
be increased due to regenerative and on-board solar cell module.
 Instead of charging the batteries in series from one charger, the battery
pack is divided in to two sets and the sets are charged via two chargers
respectively.

18.  LiFePO4 has larger life span and are lighter and cleaner.
 They are costlier than lead acid.
 Until the next breakthrough in battery technology, LiFePO4 suits best
for electric vehicles.
 We could say that we have partially overcome the battery issue
demerit.

19. The amount of power a vehicle needs can be approximately calculated
by adding the aerodynamic drag and rolling resistance.
Aerodynamic drag may be calculated using the following formula.
P drag = 0.5 ρ Cd A V3
Where,
ρ – Density of air
C d – Coefficient of drag
A – Frontal area of vehicle in m2
V – Speed in m/s

20. Rolling resistance may be calculated as follows:
P rr = V C rr g m
Where,
V – Speed in m/s
Crr – coefficient of rolling resistance
G – 9.81m/s2
m – Mass (kg)

21. P drag = 0.5 (1.225)(0.8)(1)(16.7)3 = 2282W
P rr = (16.7) (0.04) (9.81) (230) = 1507W
Total power required (Pt) = P drag + P rr
Pt = 3789W
Speed (rpm) = (m/s) 60/circumference of wheel
Assuming diameter of wheel= 14’’ = 355mm=0.355m
rpm = (16.7)60/ 0.355 = 900
Torque (Nm) = 9.55 (power)/Speed(rpm)
= 9.55(3789)/900
= 48.88Nm

22.  Currently, electric vehicles are getting more popular due to its
ecofriendly nature and cost effective nature.
 The only drawback in case of electric vehicles is that they have less
battery life and the longer charging time.
 This drawback can be overcome by the use of a super-capacitor in
parallel with the conventional battery to provide the large starting
current.
 In future, there is a large scope for electric vehicles. Efforts are done
to increase the efficiency and performance of the current model.

23.  www.Sciencedirect.com
 www.wikipedia.com
 Ieee journal

24. THANK YOU