Abstract of the Research Paper Energy sources using exhaustible energy at its input are being discouraged because they cause significant damage to the environment and human beings. Solar energy is considered one among the clean and green energy sources because it takes sunlight as its input which is a renewable energy source. There are many places in the world where electricity is not constant or not available. There are also cases where solar energy is neglected by people simply because of a lack of knowledge of its efficiency, and it is basically considered non-efficient. The purpose of this research is to build a solar charger, test its workability, and compare its efficiency with a regular wall charger to provide information for it to be used by both rural and urban people. Both quantitative and qualitative approaches were used appropriately, and most efficient circuit parts and appropriate testers were used in this research study to achieve the objectives. It was found that the solar charger was almost as efficient as a regular wall charger. There were some factors which decrease the efficiency of the solar charger which may be analyzed by future researchers on this concept. In conclusion, after being found that a solar charger is as efficient as a regular wall charger, its use must be encouraged by both rural and urban people. Keywords: Solar charger, wall charger, comparative study

1. BUILDING AN EFFICIENT SOLAR CHARGER AND COMPARING ITS CHARGING
SPEEDS WITH A REGULAR WALL CHARGER
SUKHPREET SINGH
KENNETH JAYE L. TAER
SCIR JADE T. SINADJAN
PRINCESS SOPHIE G. SALIGOYAN
KENNETH T. COMAYAS
A RESEARCH PROPOSAL SUBMITTED TO THE FACULTY OF THE
DEPARTMENT OF BIOLOGY, COLLEGE OF ARTS AND
SCIENCES, CENTRAL MINDANAO UNIVERSITY,
IN PARTIAL FULFILMENT OF THE
REQUIREMENTS FOR THE
COURSE IN
SCIENCE, TECHNOLOGY, ENGINEERING, AND MATHEMATICS (STEM)
MAY 2019

2. ii
TABLE OF CONTENTS
Page
TITLE PAGE i
TABLE OF CONTENTS ii
LIST OF TABLES iii
LIST OF FIGURES iv
LIST OF APPENDICES v
ABSTRACT vi
INTRODUCTION 1
Objectives of the Study 2
Significance of the Study 2
Scope and Limitations of the Study 3
REVIEW OF RELATED LITERATURE 4
Importance of renewable sources of energy 4
Building a solar charger 5
Testing the voltage 6
Testing the efficiency 6
METHODOLOGY 7
Building a solar-powered gadgets charger 8
Voltage testing of the whole circuit at different parts 10
Efficiency comparison between the solar charger and
a regular wall charger 11
RESULTS AND DISCUSSION 13
Building a solar-powered gadgets charger 13
Voltage testing of the whole circuit at different parts 14
Efficiency comparison between the solar charger and 16
a regular wall charger
CONCLUSION 20
REFERENCES 21
APPENDICES 23
Letter of Circuit Verification 24
Supporting Documentation for the circuit verification 25
Documentation for the tests and building of the solar charger 26
CURRICULUM VITAE 29

3. ii
LIST OF TABLES
Table Page
1 The expected voltage at different parts of the 10
circuit of the solar charger
2 Budget of this research study 13
3 The voltage at different parts of the circuit of the solar charger 15
4 Statistical comparison between the charging speed of solar 16
charger and a regular wall charger for cellphones
5 Statistical comparison between the charging speed of solar 17
charger and a regular wall charger for the built-in power
bank of the solar charger

4. iii
LIST OF FIGURES
Figure Page
1 The technical circuit 7
2 The intuitive circuit 7
3 Solar charger 14
4 Time taken (in minutes) by each charger to charge 18
the cellphone and the power bank by 50%.
5 Effect of temperature on voltage and current 19
output of the solar charger

5. iv
LIST OF APPENDICES
Appendix Page
1 Letter of Circuit Verification 24
2 Supporting Documentation for the circuit verification 25
3 Documentation for the tests and building of the solar charger 26

6. v
ABSTRACT
Energy sources using exhaustible energy at its input are being discouraged because they
cause significant damage to the environment and human beings. Solar energy is considered one
among the clean and green energy sources because it takes sunlight as its input which is a
renewable energy source. There are many places in the world where electricity is not constant
or not available. There are also cases where solar energy is neglected by people simply because
of a lack of knowledge of its efficiency, and it is basically considered non-efficient. The
purpose of this research is to build a solar charger, test its workability, and compare its
efficiency with a regular wall charger to provide information for it to be used by both rural and
urban people. Both quantitative and qualitative approaches were used appropriately, and most
efficient circuit parts and appropriate testers were used in this research study to achieve the
objectives. It was found that the solar charger was almost as efficient as a regular wall charger.
There were some factors which decrease the efficiency of the solar charger which may be
analyzed by future researchers on this concept. In conclusion, after being found that a solar
charger is as efficient as a regular wall charger, its use must be encouraged by both rural and
urban people.
Keywords: Solar charger, wall charger, comparative study

7. INTRODUCTION
Coal-based steam power plants and nuclear power plants cause pollution during the
generation of electricity which is likely to be more harmful in the future due to large electricity
generating capacity (Gohil et al., 2017). There are many other sources of energy such as thermal
energy, nuclear energy, energy producers by the consumption of petroleum or natural gas, etc.
which produce pollution and consume exhaustible sources of energy. The solar energy,
hydroelectric energy, and the wind energy are the most environment-friendly electricity
generators from the renewable sources of energy causing zero to very negligible environmental
effect.
According to Hossain (2015), solar energy is ideal for the places far away from
electricity grids providing independent electric power once there is sunlight. These are non-
polluting, do not deplete the natural resources, and are quite cheap in the long run. Renewable
energy does not emit carbon dioxide and other harmful greenhouse gases which contribute to
global warming, therefore, for minimizing harmful emissions and expenses on imported fuels,
renewable energy should be encouraged as the electricity demand is increasing (Maroma,
2014). There is a need to promote the electricity generators which use renewable energy as its
input because the exhaustible energy sources could not exist forever and those exhaustible fuels
have some unalterable uses in machines, engines, etc. Secondly, the electricity generators from
exhaustible sources produce comparatively high amounts of pollution. Therefore, this research
study will be conducted to take a step towards renewable energy and to compare its efficiency
as a cellphone charger with a regular wall charger.

8. 2
Objectives of the Study
In order to build and compare the solar charger as mentioned above, the objectives of
this research study are to:
1) build a solar-powered cellphone charger from the needed components;
2) test its voltage at different places of the circuit and at different time frames for
assuring the proper working condition and safety; and
3) compare its efficiency with a regular wall charger
Significance of the study
Electricity can be supplied to devices and batteries using a solar charger, in addition,
they are portable, a set of solar cells is installed in a stationary location and connected to devices
or battery bank for off-peak usage, and they can be used when the electricity is cut out or not
constant (Gohil et al., 2017). In rural areas where electricity is not constant and sometimes
where it takes days to arrive back after one blackout, solar energy can be a very effective
solution. By using the solar powered charger, one can charge their mobile battery in remote
areas where there is a problem of electricity (Kamble et al., 2014). Solar energy is a completely
renewable source of energy and it does not cause any harm to the environment or any living
being. Solar power is used in space satellites in NASA, SpaceX, and almost every satellite
which leaves Earth and stays far away from any other source for recharging (Cougnet et al.,
2004). The solar charger uses energy from the sunlight to convert it into solar energy by using
the combination of solar cells and some necessary circuits, therefore, the setup is a one-time
investment. It is initiated by the manufacture of a very small solar charger which could charge
low power consuming gadgets like cell phones, radios, small rechargeable flashlights, etc., and
enhance the rural life in a very significant way. Comparing a solar charger gives information
about its efficiency, therefore, increasing the knowledge about it to the people who have not

9. 3
tried the renewable sources of energy. It also provides further ground for efficiency
management for future researchers. Basically, this comparison study would provide
information about the efficiency of a solar charger, which could lead to further researches for
efficiency improvement and the increased use of this renewable source of energy.
Scope and limitations of the study
The solar charger for this research study will be built by the senior high school students
after reading and knowing about building a solar charger from the accredited sources. Many
kinds of circuits and charging methods can be used in charging the cellphones from a solar
charger but the methods used in this study will be the most widely used by researchers. The
design of the solar charger is not based on one single source but a combination of multiple
sources to increase its productivity. The most efficient and cheapest components will be used
so that the components would be affordable for the researchers and potential buyers. The results
will be based on the cellphones used during this research which will be specified in the
methodology of this research. The concept of constant temperature will not be included in this
research study during the solar charger execution, but it will be made sure that the consistent
amount of sunlight is available to the solar panels. The solar panels could work only in sunlight;
therefore, the charger would be equipped with a power bank made up of four lithium- ion
batteries. In general, the comparison is to be made with a specific model of a solar charger,
therefore, may not be applicable to all solar charging methods.

10. REVIEW OF THE RELATED LITERATURE
Importance of renewable sources of energy
According to Alrikabi (2014), Many different countries currently rely on non-
renewable sources of energy such as coal, oil, and natural gas. Fossil fuels or non-renewable
energy sources are finite in an amount that will eventually dwindle, becoming too expensive
or too environmentally damaging to retrieve. The huge consumption of fossil fuels affects the
environment in many ways such as affecting the ecological cycle, leading to global warming
and climate change. Because of the technological advancements vehicles nowadays come with
very high fuel efficiency for addressing the discussed problem. In accordance with the high
efficiency of vehicles, renewable sources of energy are also given importance.
As written by Mardani et al. (2015), renewable sources basically include solar energy,
wind energy, and hydroelectric energy, etc. Renewable energy sources cause the least
environmental damage; therefore, they are widely being used for producing clean and
environment-friendly energy. As supported by National Renewable Energy Laboratory
(NREL) (2001), renewable energy uses energy sources which are continuously replenished by
nature such as sun, wind, water, Earth’s heat, and plants. By using renewable energy
productions methods, the input from above-mentioned sources can be turned into electricity,
heat, chemicals, and mechanical energy. As stated by Cougnet et al. (2006), renewable energy
is being used in all alterable energy systems. Space satellites also use the solar energy while
orbiting around the earth. Solar Renewable energy sources are considered the future energy of
the world, therefore, the ways in which it can be used efficiently and comfortable are being
researched by many researchers worldwide.

11. 5
Building a solar charger
According to Solenergy Systems Inc. (2016), the input of solar generators or chargers
is a consistent amount of sunlight which is widely available in the Philippines. Solar systems
and chargers giving a good amount of efficiency could be made. According to Dhal et al.
(2016), solar charger basically takes sunlight as its input and using solar panels it converts the
sunlight into electricity, the electricity could then be used directly or stored in the batteries. It
needs the basic component namely solar panel, voltage regulators depending on the desired
input and output, and batteries and charging modules for battery charging for storing the
energy.
According to Biswal and Sabyasachi (2012), different dc-dc converters can be used
depending on the purpose they serve, such as step-up converters for increasing the voltage, and
step-down converters for decreasing the voltage. A step-down converter is much efficient than
a linear voltage converter especially when the output voltage is much lower than the input
voltage (Zhang, 2013). Therefore, using a step-down converter as a voltage regulator is ideal
for a solar charger. According to Gohil et al. (2017), a solar charger can be used where there is
a lack of a consistent amount of supplied electricity. Solar energy is used in houses as an
alternative of electricity provided to reduce costs, and to use while the electricity is not constant
or not present. Solar energy is considered a more reliable and environment-friendly energy
source because the energy converted can be stored in batteries for off-peak usage. Building a
solar charger and testing its efficiency as an alternative to a wall charger is a step towards the
implication of renewable energy.
Regarding the design of the solar charger, many pieces of information are taken from
different sources. According to Akin (2012), a solar panel can be directly attached to a USB
type voltage regulator to use it as a DC charger. According to Creative Life (2017), a power
bank can be attached toa solar charger to store energy for off-peak usage. According to Lopa

12. 6
et al. (2016), DC-DC converters are more efficient than linear converters. All these concepts
are read, and an efficient solar charger is to be made.
Testing the voltage
According to Brennan (2019), a multimeter tester can be used to measure the voltage
of electric circuit and systems to basically to ensure the proper functioning of the electric
circuit. For measuring the voltage using a digital multimeter, two wires coming out of the
multimeter are connected in the circuit at the desired place with correct polarity, and the
multimeter displays the voltage in its display LCD. Different kinds of multimeters can be used
for measuring the voltage of a circuit, however, the digital multimer is comparatively easier to
use and cheaper to buy.
Testing the efficiency
According to Aarniovuori et al. (2013), the efficiency of a charger can be measured by
its input value and its output value, however, while comparing the efficiency of two systems in
one aspect, that aspect of the systems to be compared can be contrasted in the simplest units.
Therefore, in the case of efficiency comparison of a solar charger and a wall charger, the
charging speeds can be compared. As mentioned above, the solar charger can be used directly
to charge cellphones, or the energy can be stored in the power banks for off-peak usage.
Regarding the efficiency of the power bank, the time it takes to get charged from a solar charger
and a regular wall charger could be compared. According to Roger et al. (2007), multiple trials
must be done in order to obtain a precise and accurate result of an experiment, therefore, three
trials for efficiency testing of the charger would be made.

13. METHODOLOGY
Figure 1: The technical circuit
Figure 2: The intuitive circuit

14. 8
A. Building a solar-powered gadgets charger
The model is shown above (Figure 1 and Figure 2) is the desired or targeted model
which researchers will be building for this comparative study. It includes the following
components:
1) 12 volts 10 watts solar panel: It captures the sunlight and converts it into electrical
energy, the solar panel for this project will be bought from the online shopping website
namely Shoppe. The 12V and 10W solar panel will be bought because it provides
enough energy to the circuit, and it was found the cheapest while comparing in all the
online stores.
2) Step down voltage converter: This lowers the voltage of a higher voltage source. This
will also be bought from Shoppe.
3) 5V battery bank charging module: This is the circuit which is specialized in taking 5
voltage of current and charging the 3.7V 18650 Li-ion batteries connected batteries to
it, this component will be bought from Shoppe as well.
4) Wires: Wires are used for connecting different parts of the circuit to one another. Wires
in this circuit also include a micro USB cable which will be an original Samsung
charger cable. Wires could be bought from the nearest electrical hardware shop, in this
research, these will be bought from NVM Marketing, Valencia City, Bukidnon,
Philippines.
5) 4 Lithium-ion 18650 3.7V batteries: The batteries store energy which could be used
anytime, especially the 18650 3.7V batteries are quite efficient in storing energy as they
are used in many chargeable devices such as power-banks, vapes, laptop batteries, solar
chargers, etc. These are taken from the old laptop batteries for this research, but these
can be bought either online or from nearby electrical shops also.

15. 9
As shown in figure 1 and figure 2 above, this solar charger converts solar energy into
electrical energy and stores it in the batteries. Since this circuit is composed of many
components, the functions of all the components of the solar charger are explained as follows:
1. The solar panel captures sunlight and the mechanism inside it converts the solar energy
into electrical energy.
2. Some wires connect the solar panel to buck converter or voltage regulator and then to
mini USB cable, the purpose of the buck converter is to decrease the voltage to 5V.
3. Mini USB transfer the electricity converted by the solar panel to the 5V battery bank
charging module.
4. The charging module limits the voltage to 3.7V and transfers the electricity to 4 Li-ion
18650 3.7V batteries.
5. From the charging module outlet, all the small power consuming devices such as mini
USB fans, mini USB lights, keypad cell phones, touch-screen cell phones, chargeable
headphones/earphones, small chargeable batteries, pocket Wi-Fis, etc. could be charged
or powered after the batteries are charged.
In the last part of the building of the design of a solar-powered gadgets charger, the
dimensions and the weight of the charger will also be measured. The circuit design chosen in
this research study is inspired by many different sources namely, past researches on the ‘solar
charger’ topic, researches on the different types of dc-dc converters, informational articles and
forums on the topic ‘Linear Voltage Converter vs Step-down Buck Converter’, research papers
about making a complete and working circuit, and informational videos on ‘using old laptop
batteries as a power bank using charging module’. Using all the mentioned sources above,
researchers have come up with the most efficient and economical solar charger by knowing the
correct use of each component to be used. Therefore, the components used are the most
economical and efficient, since this charger is intended for rural life enhancement.

16. 10
B. Voltage testing of the whole circuit at different parts
The digital multimeter device and USB voltage tester will be used in order to test the
voltage of the circuit at different parts. Digital multimeter device is powered by batteries, uses
two wires, one as positive and another as negative, those wires are connected to a specific place
in circuits with correct polarity to test the voltage at that specific point. A USB voltage tester
is a USB like a device which is added in a circuit using the USB port to know the voltage and
the current at that part of the circuit. This test will determine the proper functionality of the
circuit and determine if there would be any waste of energy in the circuit. Most of the digital
multimeters are intuitive and easy to use devices to test the voltage, therefore, it is chosen to
test the voltage. The estimated voltage at the input and output of all the components is shown
in table 1:
Table 1. The expected voltage at different parts of the circuit of the solar charger
Components Solar Panel Buck Converter Charging Module Batteries
Input Voltage N/A (sunlight) 18-21V 5V 3.7V-4.2V
Output Voltage 18V-21V 5V Output to
batteries: 3.7V
An outlet for
charging: 5V
N/A (connected
to the charging
module)
If the voltage fluctuates or remains lower or higher than the estimated voltage, then the
circuit will be checked for any possible flaw and revised.

17. 11
C. Efficiency comparison between the solar charger and a regular wall charger
The time required for the power bank to get charged by the solar panel and a wall
charger will be determined and compared. The time taken for the battery bank to charge the
devices like cell phones will also be determined and compared to the charging speed of a wall
charger to make some recommendations. The cellphone to be used for this research study is
Lenovo S90-A whose battery capacity is 2,300 mAh. The power bank to be used as the capacity
of 10,000 mAh which is also designed by the researchers using lithium-ion batteries.
The process by which the speed of charging of cellphones by the solar charger and a regular
wall charger will be compared is as follows:
1) Two similar cellphones will be powered off and with a specific percentage level.
2) They will be put on charging, one by the solar charger and another by the regular wall
charger.
3) Time taken to charge both cellphones by 50 percent of battery level will be noted and
compared.
4) This test will be repeated thrice, one per day, to get as accurate results as possible.
For the purpose of testing the charging speed of power-bank by both the solar charger and
a regular wall charger, the following procedure will be followed:
1) The input of the charging module will be connected once to the solar charger, and again
to a regular wall charger.
2) The percentage level of batteries will be started from a specific percent level and the
batteries will be charged by 50 percent by each charger.
3) This test will also be repeated thrice, one per day, for obtaining as accurate results as
possible.

18. 12
In both the tests, 50% of the battery will be charged because it will provide the best estimate
because charging up to a small percentage level and comparing may give inaccurate results,
batteries may take less or more time in a specific interval especially if that interval is as short
as 5% or 10%, since the interval level is as big as half of the whole battery capacity, and in
both tests the starting and ending point will be same, therefore, the most accurate results can
be expected. In the last part of the efficiency test, the effect of temperature on the voltage and
current output of the solar charger will also be measured.

19. RESULTS AND DISCUSSION
A. Building the solar-powered gadgets charger
The solar charger was built as shown in the intuitive circuit above and as well as in figure
3. Many small trials were done before using it as a cellphone charger. After assuring the
workability of the charger it was used in this research. It weighs around 1.25 kilograms and its
dimensions are 35.5cm×24.0cm×3.5cm. Expenses occurred in this research study are shown
below (table 2). A total expense of PHP 2,785.04 occurred in this research study, but the laptop
batteries were obtained from an old laptop battery in this study, therefore, actual expenditure
by researchers was only PHP 1,785.04. The overall cost for making the solar charger is PHP
2,306.04 if any reader of this research would like to imitate this model.
Table 2. Budget of this research study
Item Expense
Solar Panel PHP 550 (including delivery)
USB Cable PHP 110
DC-DC Buck Converter PHP 245 (including delivery)
Digital Multimeter Tester PHP 135
USB Voltage Tester PHP 138.39 (including delivery)
Charging Module PHP 106.65 (including delivery)
Wires PHP 21
Batteries × 4 N/A (from old laptop battery) Cost PHP 1,000 (4 × batts approx.)
Travel Costs PHP 200
Internet Fee PHP 300
TOTAL PHP 2,806.04

20. 14
Figure 3: Solar charger
B. Voltage testing of the whole circuit at different parts
Digital multimeter device and USB voltage tester were used appropriately to find the
voltage of the circuit at different parts to ensure to the proper functionality of the circuit, and
to avoid any damage to the circuit or the mobile phone. Table 4 shows the results of the
voltage test conducted in this research study.
18V 10W
Solar Panel
Wires
DC-DC buck
converter
10,000 mah
Power bank
Micro USB
USB Voltage
tester

21. 15
Table 3. The voltage at different parts of the circuit of the solar charger
Components Solar Panel Buck Converter Charging Module Batteries
Input Voltage
Expected Voltage
Trial 1:
Trial 2:
Trial 3:
Average:
N/A
(sunlight) 18-21V
19.38V
19.31V
18.75V
19.15V
5V
5.05V
4.93V
5.00V
4.99V
3.7V-4.2V
3.79V
3.66V
3.89V
3.78V
Output Voltage
Expected voltage
Trial 1:
Trial 2:
Trial 3:
Average:
18V-21V
19.38V
19.31V
18.75V
19.15V
5V
5.05V
4.93V
5.00V
4.99V
Charging outlet:
5V
5.00V
4.96V
5.06V
5.01V
N/A (connected
to the charging
module)
It was ensured by the test that the solar charger is built without the technical faults. It was
found that the voltage fluctuated when there was a change in the amount of sunlight being
captured by the solar panel due to the disturbances like clouds, or humidity. The voltage tests
were conducted when the conditions were normal such as sunlight was constant, and clouds
were not disturbing the sunlight captured by the solar panel.
The solar panel placed under sunlight and the voltage measured directly on its output wires
give an average of 19.15V. According to the research data obtained by Kaithari et al. (2017),
using a nearly similar solar panel, they obtained 20.8V from the solar panel which also agrees
with the data of this research study and solar panel output information. All other components’
voltage was fixed by the circuits and modules, giving enough voltage to each component. In

22. 16
general, the solar charger passed the voltage test and it was ready to be used as a gadgets’
charger.
C. Efficiency comparison between the solar charger and a regular wall charger
The solar charger was set up to charge cellphones and the power bank several times. It was
found out that the solar charger made in this research study was giving enough current to charge
properly the cellphones and the power bank. In order to compare the efficiency of the solar
charger with a regular wall charger, trials of charging were conducted and are listed below
(table 3).
Table 4. Statistical comparison between the charging speed of solar charger and a regular wall
charger for cellphones
Charger used
Time taken to charge the cellphones
Trial 1 Trial 2 Trial 3 Average
Regular wall charger 54.37 minutes 62 minutes 59 minutes 58.46 minutes
Solar charger 61 minutes 56 minutes 64 minutes 60.33 minutes
It was found out that the average time taken by a regular wall charger was 58.46 minutes
and the average time taken by the solar charger was 60.33 minutes. Both chargers are found to
be almost the same in terms of charging speed when a cellphone was put on charging. It was
observed using the USB voltage tester that the current supplied by both the wall charger and
the solar charger was approximately the same.
Built-in power bank of the solar charger was also used as a device to be charged for
comparing the efficiency of the solar charger and a regular wall charger, following table (table
4) shows the results of the test:

23. 17
Table 5. Statistical comparison between the charging speed of solar charger and a regular wall
charger for the built-in power bank of the solar charger
Charger used Time taken to charge the power bank
Trial 1 Trial 2 Trial 3 Average
Regular wall charger 210 minutes 224 minutes 199 minutes 211 minutes
Solar charger 227 minutes 219 minutes 193 minutes 213 minutes
On average, a regular wall charger takes 211 minutes and the solar charger takes 213
minutes to charge the power bank by 50%. It is found out that both chargers are almost the
same in terms of charging speed when a power bank is put on charging. The current supplied
again was observed nearly the same by both the chargers.

24. 18
The following bar graph (figure 5) shows the comparison of the charging speeds of both the
chargers in detail:
Figure 4: Time taken (in minutes) by each charger to charge the cellphone and the power
bank by 50%
As discussed above and shown in the bar graph, there is a very small difference in the
charging speeds of a wall charger and the solar charger. There may be some factors which
lower the efficiency of the solar charger such as temperature, the heating of circuit components,
inconsistent sunlight, etc. According to the findings of Cabrillos et al. (2013), the solar charger
is as efficient as a wall charger. With the use of voltage testers and cellphones, they found out
that the current as well as voltage supplied by the solar charger was nearly same as a regular
wall charger, but the instantaneous output depends on the sunlight it captures.
0
50
100
150
200
250
Trial 1 Cellphone Trial 2 Cellphone Trial 3 Cellphone Trial 1
Powerbank
Trial 2
Powerbank
Trial 3
Powerbank
Time taken (in minutes) by each charger to charge the
cellphone and the power bank by 50%
Solar Charger Wall Charger

25. 19
The thermometer was used to know the effect of the temperature on the voltage and current
output of the solar charger. Following graph (figure 5) shows the effect of the temperature on
the voltage and current outputs of the solar charger:
Figure 5: Effect of temperature on voltage and current output of the solar charger
As shown in the graph, there is no current output at the temperatures below 34°C, and
it starts slowly at 34°C and gradually increases till 38.5°C and then it starts to lower and
stabilize by 0.86 amps at the temperatures above 38.5°C. There is an element namely heating
of the plate of the buck converter which could also affect the current and voltage, but the
temperature test was conducted making sure that the plate is not abnormally hot. According to
the findings of Thong et al. (2016), temperature affects solar panels output current, voltage,
and general efficiency. It is observed in their research findings that solar panel is at the highest
efficiency and current output value when the temperature is between 35°C to 40°C which also
agrees with the findings of this research study.
4.52
4.54
4.66
5.08
5.03
5
5
5.05
5.05
5.04
5.05
5.05
0
0
0.16
0.61
0.56
0.76
0.96
0.84
1.16
0.86
0.86
0.86
3 2 . 2 3 3 . 1 3 4 3 4 . 7 3 5 . 2 3 6 . 4 3 7 . 2 3 7 . 9 3 8 . 5 3 9 . 7 4 0 . 2 4 0
EFFECT OF TEMPERATURE ON VOLTAGE AND
CURRENT OUTPUT OF THE SOLAR CHARGER
Voltage (in V) Current (in Amp)

26. CONCLUSION
The aim of this research study was to compare the practical knowledge of the efficiency
of a regular wall charger and a solar charger; therefore, an efficient solar charger was built by
the researchers and the tests were conducted. On average, a wall charger takes 58.66 minutes
and the solar charger takes 60.33 minutes to charge the cellphone by 50%; and a wall charger
takes 211 minutes and the solar charger takes 233 minutes to charge the built-in power bank of
the solar charger by 50%. The temperature where the solar charger was seen working the best
is 38.5°C. It was found out that a wall charger and solar charger are almost the same in terms
of their charging speeds. There can be some factors which could lower the efficiency of the
solar charger such as temperature, heating of the plate in the circuit due to consistent use,
sunlight being captured, etc. In conclusion, the solar charger is as fast as a wall charger for
charging cellphones and power banks, but the factors affecting its efficiency could be analyzed
and used for further improvements.
Recommendation by researchers is that a solar charger is as fast as a wall charger so it
should be given importance where there is inconsistent, interrupted, or expensive electricity so
that the environment could be saved, and the life of the rural people could be enhanced. This
research study also recommends future researchers to work on providing an efficient heat sink
to this solar charger to increase its productivity. In general, this model of a solar charger is
being successful in practicality, and its use must be encouraged as well as the upgrades in this
charger could be made for making it as productive as possible.

27. REFERENCES
Aarniovuori, L., Kosonen, A., Sillanpää, P., & Niemelä, M. (2013). High-power solar inverter
efficiency measurements by calorimetric and electric methods. IEEE Transactions
on Power Electronics, 28(6), 2798-2805. doi: 10.1109/TPEL.2012.2221166
Akin, B. (2012). Solar power charger with universal USB output. 2012 IEEE 5th India
International Conference on Power Electronics (IICPE).
doi:10.1109/iicpe.2012.6450447
Alrikabi, N. M. A. (2014). Renewable energy types. Journal of Clean Energy Technologies,
2(1), 61-64. doi: 10.7763/JOCET.2014.V2.92
Biswal, M., & Sabyasachi, S. (2012). A study on recent dc-dc converters. International
Journal of Engineering Research and Applications (IJERA), 2 (6), 657-663. Retrieved
from
https://pdfs.semanticscholar.org/915c/4042f1c938f67ea8597287d22ee23bdbe5c2.pdf
Brennan, E. (2019). How to use a multimeter to measure voltage, current and resistance.
Retrieved from https://dengarden.com/home-improvement/Using-a-Multimeter
Cabrillos, K., Geaga, J. V., Natividad, R. V., & Santua, R. C. (2013). Aside from being
portable, a solar-powered phone charger is as efficient as the wall charger (Bachelor’s
Thesis). Retrieved from https://www.slideshare.net/zeroyan/final-research-to-print
Cougnet, C., Sein, E., Celeste, A., & Summerer, L. (2004). Solar power satellites for space
applications. Journal of the British Interplanetary Society, 55, 1-8. Retrieved from
https://www.researchgate.net/publication/237291237_Solar_power_satellites_for_spa
ce_ applications.
Creative Life. (2017, Jun 16). How to make a 2 in 1 solar power bank from scrap laptop
battery homemade [Video file]. Retrieved from
https://www.youtube.com/watch?v=1IzWSbJ5Ff8&t=10s
Dhal, S. B., Agarwal, A., & Agarwal, K. (2016). Solar powered mobile power bank systems.
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10.12691/ajeee-4-5-4
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Journal of Electrical and Electronics Research, 3(1), 42-46. Retrieved from
www.researchpublish.com/download.php?file=Solar%20Panel%20Based%20Mobile
%20Charger%20and-1009.pdf&act=book Solar Panel Based Mobile Charger and
Small Led Lamp

28. 22
Kaithari, D. K., Ismaili, A. K., & Achuthan, M. (2017). Solar power operated table for charging
Electronic gadgets. International Journal of Students Research in Technology &
Management,5(3), 11. doi:10.18510/ijsrtm.2017.533
Kamble, R., Yerolkar, S., Shirsath, D., & Kulkarni, B. (2014). Solar mobile charger.
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(IJIRCST), 2(4), 35-39. Retrieved from http://www.ijircst.org/DOC/80a7b7228-744f-
4b42-8678-b8b4d437b339.pdf
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of dc-dc converters. International Research Journal of Engineering and Technology,
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-DC_Converters
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achieve performance stability of selected ground reaction force variables during
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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3778688/.
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http://solenergy.com.ph/solar-power-philippines/
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temperature effects on its efficiency. International Conference on Electrical
Engineering and Electronics Communication System, 2, 1-6. Retrieved from
https://www.researchgate.net/publication/310673805_Analysis_of_Photovoltaic_Pane
l_Temperature_Effects_on_its_Efficiency
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Retrieved from https://www.analog.com/media/en/technical-
documentation/application- notes/an140fb.pdf

29. APPENDICES

30. 24
Appendix 1. Letter of verification of the circuit

31. 25
Appendix 2. Supporting documentation for the circuit verification
Me and my groupmates asking for the signature of Mr. Magadan (Electrical Engineer)
on our circuit verification letter
Mr. Magadan (Electrical Engineer) signing the letter after reviewing our concept and circuit

32. 26
Appendix 3. Documentation for the tests and building of the solar charger
Mar 19, 2019, 10:00am
Settingupthe solar
charger
Mar 24, 2019, 11:32am
Gatheredall the
components
Mar 26, 2019, 10:30am
Finishedthe essential
setups
Mar 30, 2019, 11:00am
Conductedthe voltage
testwithpowerbank
Apr 15 – Apr 29, 2019
Conducted the efficiencytestusingasolarcharger as well asa regularwall charger
Apr 6, 2019, 2:00pm
Conductedthe solar
panel voltage test

33. 27
April 20, 2019, 1:00pm
Temperature effecttest
April 27, 2019, 3:00pm
Temperature effecttest
April 28, 2019, 11:00am
Temperature effecttest
April 14, 2019, 12:00pm
Solarcharger inuse
April 17, 2019, 1:00pm
Solarcharger inuse
May 8, 2019, 5:00pm
Complete view of solar
charger

34. 28
May 04, 2019, 6:00 pm
Weighing the solar charger
Apr 19, 2019, 12:00pm
Group Photo while testing
May 01, 2019, 12:00pm
Group Photo while testing

35. CURRICULUM VITAE
PERSONAL DATA:
LAST NAME: COMAYAS
First Name: Kenneth
Middle Name: Tequillo
Address: P-3, Bagontaas, Valencia city
Cellphone no.: 09263711869
Email: ken23comayas@gmail.com
Marital Status: Single
Date of Birth: july 11, 2000
Gender: Male
Country of Origin: Philippines
Present Nationality: Filipino
Languages and Fluency Level: English, Filipino, Cebuano
EDUCATION:
Name of the School Address Years Attended
Bagontaas Central Elementary School Bagontaas, Valencia City, Bukidnon 2007-2013
Valencia National High School Valencia City, Bukidnon 2013-2017
Central Mindanao University Musuan, Bukidnon, Philippines 2017-2019
AWARDS:
 Best in spelling [grade 2-3]
 Best in English [Grade 4]
 Loyalty award [Grade 6]
 MTAP 3rd place [grade 6]

36. 30
PERSONAL DATA:
LAST NAME: SALIGOYAN
First Name: Princess Sophie
Middle Name: Grapinag
Address: P3B Managok Malaybalay City
Cellphone no.: 09360746178
Email: princesssophiesaligoyan@gmail.com
Marital Status: Single
Date of Birth: January 6, 2001
Gender: Female
Country of Origin: Philippines
Present Nationality: Filipino
Languages and Fluency Level: English, Filipino, Cebuano
EDUCATION:
Name of the School Address Years Attended
Managok Elementary School Managok, Malaybalay City, Bukidnon 2007-13
Managok National High School Managok, Malaybalay City, Bukidnon 2013-17
Central Mindanao University Musuan, Bukidnon, Philippines 2017-19
AWARDS:
 Top outstanding student (2014-2017)
 SSG President (2016-2017)
 Bukidnon District Church Officer
 Bukidnon District Bible Quiz 2nd Placer

37. 31
PERSONAL DATA:
LAST NAME: SINADJAN
First Name: Scir Jade
Middle Name: Tilos
Address: P-6, Lower Sugod, Valencia City, Bukidnon
Cellphone no.: 09365828095
Email: jadesinadjan7@gmail.com
Marital Status: Single
Date of Birth: August 13, 2019
Gender: Male
Country of Origin: Philippines
Present Nationality: Filipino
Languages and Fluency Level: English, Filipino, vernacular(bisaya)
EDUCATION:
Name of the School Address Years
Attended
Bagontaas Central Elementary School Bagontaas, Valencia City 2007-13
Bangcud National High School Bangcud Malaybalay City Bukidnon 2013-17
Central Mindanao University Musuan, Bukidnon, Philippines 2017-19
AWARDS:
 Academic awards (Grade 2,4, 7-8)
 Best in Math (Grade 5)

38. 32
PERSONAL DATA:
LAST NAME: SINGH
First Name: Sukhpreet
Middle Name: N/A
Address: P-19, Poblacion, Valencia City, Bukidnon, Philippines
Cellphone no.: 09976234429
Email: sukhy25aspal@gmail.com
Marital Status: Single
Date of Birth: November 25, 2001
Gender: Male
Country of Origin: India
Present Nationality: India
Languages and Fluency Level: English, Punjabi, and Hindi (Fluent); Filipino (not much
fluent)
EDUCATION:
Name of the School Address Years Attended
Dashmesh Public School Aspal Kalan, Barnala Punjab India 2004-06
Silver Vatika Public School Samaon, Mansa, Punjab, India 2006-16
Central Mindanao University Musuan, Bukidnon, Philippines 2017-19
AWARDS:
 Grade 1 to 4 – 1st Placer in Academics
 Academic HONORS award (Grade 11) - April 11, 2018
 Academic HIGH HONORS award (Grade 11&12) - April 11, 2019

39. 33
PERSONAL DATA:
LAST NAME: TAER
First Name: Kenneth Jaye
Middle Name: Labay
Address: P-2, Bangcud, Malaybalay City
Cellphone no.: 099978175163
Email: kennethjaye05@gmail.com
Marital Status: Single
Date of Birth: April 12, 2000
Gender: Male
Country of Origin: Philippines
Present Nationality: Pilipoino
Languages and Fluency Level: English, Filipino, Cebuano
EDUCATION:
Name of the School Address Years Attended
Bangcud Elementary School Bangcud Malaybalay City Bukidnon 2007-13
Bangcud National High School Bangcud Malaybalay City Bukidnon 2013-17
Central Mindanao University Musuan, Bukidnon, Philippines 2017-19
AWARDS:
 Summer Reading Camp (Grade 7)
 Academic Awards (Grade 7-10) 2013-2017