The document summarizes a study on the thermal behavior of a 20Ah lithium-ion phosphate battery used in an e-bike. Thermal images and temperature readings of the battery were captured during charging and discharging at various speeds and loads. The maximum temperatures recorded were 47.9°C during discharging at 30kmph and 44°C during daytime charging. Charging at night was found to be better for improving battery life. The results indicate thermal imaging can help predict battery temperature behavior and optimize thermal management systems.

1. VELAMMAL ENGINERING COLLEGE
(SURAPET, CHENNAI-66)
DEPARTMENT OF AUTOMOBILE
THERMAL BEHAVIOUR ANALYSIS OF
(LIFEPO4) BATTERY USED IN E-BIKE
TEAM MEMBERS
Pradeep Kumar N (113218102018)
Pugalendhi S (113218102019)
Vishwa J (113218102024)
PROJECT GUIDE: Mr. P. PATHMANABAN, M.E., (Ph.D.) (ASSISTANT PROFESSOR)
X
Z

2. The objective of this study was to determine THE THERMAL
BEHAVIOR OF LITHIUM-ION PHOSPHATE (LiFePo4) 20AH BATTERY
by infrared thermograph. This study focused on the temperature distribution of
the battery at day/night charging and discharging. The thermal gradient of battery
(LiFePo4) powered bike at different speed 30kmph, 40kmph, 50kmph both idle and
load condition also evaluated. The spatial distribution of LiFePo4 cells was not stable
during the discharge process. At the end of the discharging, no crucial temperature
rise was detected. The maximum temperature was recorded as 47.9°C, 33.8°C, and
44°C at 30kmph, idle run, charging at day respectively. Most of the maximum
surface temperature was located at the lower part of the battery. The result shows
thermal imaging is an effective tool to predict the temperature behavior of battery
and provide a better thermal management system in E-bike battery development.
Abstract

3. • To assess the thermal behaviour of Lithium ion Phosphate (LiFePo4) battery of
20Ah with different charging and load discharging conditions.
To monitor the temperature readings at different condition using thermal imaging
camera and these readings are been validated with infrared thermometer.
To identify the suitable operating condition for improving battery life
Objective

4. ⮚ Low and High temperature effects
⮚ Climatic Conditions
⮚ Heat Generation
⮚ Thermal Runaway
⮚ Over Charge
Identification of problems:

5. ⮚Discharging Test:
1.With Load
2.Without Load
Thermal images & IR reading are captured on every 3km.
⮚Charging Test:
It was performed by discharging the battery initially & later
the charging take placed in a closed surface.
⮚Further the images are been taken at an effective distance of 0.5m
from the battery in a semi-enclosed area by using black cloth.
METHODOLOGY

6. Thermal Imaging Camera
Image Acquisition
Charging at Day/Night Discharging at Load
(30,40,50kmph)
Discharging at No load
(30,40,50kmph)
Temperature Analysis (FLIR
Tools Software)
Result Interpretation
Flow Chart

7. COMPONENTS
Electric Vehicle FLIR One Pro Thermal Imaging Camera

8. Lithium Ion Phosphate Battery (48V,20Ah) 10A Lithium Ion Battery Charger Infrared Thermometer

9. Mechanical Properties Values
Cell unit 9 parallel *13 series =117
Size 260mm* 170mm *70mm
Net weight 8kg
Properties Of Tested LiFePo4 Cells
Chemical Properties Descriptions
Anode MATERIAL Graphite
Cathode material Lithium Ferro phosphate
Electrolyte material Lithium perchlorate
Electrical properties Values
Nominal voltage 3.6V
Full charge voltage 54.6V
Nominal capacity 20Ah
Specific energy 90-120 Wh/kg
Energy density 325Wh/L
Maximum charge rate 1C
Maximum sustained rate 25C

10. DISCHARGING WITH LOAD
Speed
(Kmph)
Time
(Seconds)
Thermal Imaging Temperature (°C)
Infrared Thermography Temperature
(°C) Battery
Drain After
(Km)
Front Right Side Back Front Right Side Back
30
1440 40 36.2 40.8 37.5 34.9 37.7
60
3600 43.5 39.8 43.8 38.7 37.8 38.5
6120 47.9 44.6 44.5 44.2 42.1 42.3
40
0 33.8 32.2 31.7 31.3 30.9 30.1
54
2430 38.4 39.3 38.2 35.7 35.9 34.8
4860 44.2 43.8 44.1 41.9 41.3 41.9
50
0 32.6 32.1 32.7 30.1 29.8 30.1
49
1728 37.6 35.9 37.2 35.4 32.8 34.8
3672 45.7 43.1 46.7 43.4 40.9 44.3

11. DISCHARGING WITH LOAD

12. THERMAL IMAGES
At 30 kmph At 40 kmph
Low High Low High
At 50 Kmph
Low High

13. DISCHARGING WITHOUT LOAD
Speed
(Kmph)
Time
(Seconds)
Thermal Imaging Temperature (°C)
Infrared Thermography Temperature
(°C) Battery
Drain After
(Minutes)
Front Right Side Back Front Right Side Back
30
360 30.8 30.7 30.3 28.9 28.8 28.2
160
5040 32.3 31.6 31.1 31.1 30.5 31
9720 33.8 33.4 32.8 32.7 32.2 32.4
40
1620 31.3 30.2 31.2 29.1 28.3 30.1
145
4860 32 31.9 31.6 29.9 29.7 30.3
8100 33.6 32.6 33.1 31.8 30.5 31
50
0 30.9 30.6 30.5 28.8 28.5 28.4
120
3240 32.3 31.9 32.3 30.2 29.8 30.2
6480 33.7 33.6 34.4 32.3 31.5 32

14. DISCHARGING WITHOUT LOAD

15. THERMAL IMAGES
Discharging without load at three different temperatures
At 30 kmph At 40 kmph
. Low High Low High
At 50 kmph
Low High

16. CHARGING
Session
Time
(Seconds)
Thermal Imaging Temperature (°C) Infrared Thermograph Temperature (°C)
Front Right Side Back Front Right Side Back
Day
0 32.3 31.5 33.1 29.8 28.7 30.6
1800 34.7 33.8 34.5 32.4 31.7 32.6
3600 38.2 35.2 37.6 36.4 33.3 35.7
7200 40.5 39.6 40.3 38.7 37.7 38.4
Night
0 30.7 29.7 31.2 28.3 27.3 28.8
1800 33.1 32 32.6 30.9 30.3 30.8
3600 36.6 33.4 35.7 34.9 31.9 33.9
7200 38.9 37.8 38.4 37.2 36.3 36.6

17. CHARGING

18. THERMAL IMAGES
Charging at Day in three different temperatures
Low High Average
Charging at Night in three different temperatures
Low High Average

19. ⮚Based on the experiments conducted it has been found the electric vehicles should
maintained at a speed of 40 kmph, below which temperature rises due to more torque
requirement and above which temperature rises due to more power requirement.
⮚It is found that the surface temperature of the battery is initially uniform and varies with
respect to discharge time.
⮚For increasing efficiency of the battery we found out that charging in night is better for
lithium ion batteries get efficiently charged between the temperature range of 10°C to 30°C.
CONCLUSION

20. COST REPORT
SL.
NO
COMPONENTS QTY. COST (Rs).
1 FLIR ONE PRO (Thermal Imaging Camera) 1 15000.00
2 Lithium ion battery 1 10000.00
3 Charger 1 4000.00
4 Infrared Thermometer 1 2000.00
5 Running Cost - 500.00
6 Miscellaneous Expenses - 500.00
Total 32000.00

21. FUTURE SCOPE
⮚More thermal images of the lithium ion phosphate battery can be
taken to obtain a dataset.
⮚Using the dataset, deep learning techniques we can able to predict the
accurate lifecycle and other defects that occur in this lithium ion
phosphate battery
⮚The heat distributing regions can be provided with cooling system by
analyzing the battery temperature using the datasets obtained.
⮚These above methods can be implemented to all other types of
lithium-ion batteries which would be useful for future applications

22. REFERENCES
1. Jaewan Kim et al., (2019) “Review on battery thermal management system for electric vehicles”, Applied
Thermal Engineering, Volume 149, February 2019, Pages 192-212.
2. Noshin Omar et al., (2014) “Lithium ion phosphate based battery – Assessment of the aging parameters and
development of life cycle model”, Applied Energy, Volume 113, January 2014, Pages 1575-1585.
3. Qian Wang, Bin Jiang, Bo Li, Yuying Yan (2016) “A critical review of thermal management models and
solutions of lithium-ion batteries for the development of pure electric vehicles”, Renewable and Sustainable
Energy Reviews, Volume 64, October 2016, Pages 106-128 .
4. Qingsong Wang et al., (2012) “Thermal runaway caused fire and explosion of lithium ion battery”, Journal of
Power Sources, Volume 208, June 2012, Pages 210-224.
5. Shuai Ma et al., (2018) “Temperature effect and thermal impact in lithium-ion batteries: A review”, Progress in
Natural Science: Materials International, Volume 28, Issue 6, December 2018, Pages 653-666.

23. Any Queries?

24. Thank You