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The•Fourth•International•Renewable•Energy•Congress•
December•20-22,•2012•–•Sousse,•Tunisia•
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848•
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IREC2012-EMS-120/O•
Performance Testing Of Mobile Phone Battery
O. A. Babatunde1, B. O. Onafeso, O. Adegbenro
National Centre for Energy Efficiency and Conservation
(The Energy Commission of Nigeria)
Faculty of Engineering, University of Lagos, Akoka, Yaba Lagos, Nigeria
1Corresponding Author: boribabatunde@gmail.com
Abstract: The advent of mobile telephony in Nigeria has brought a lot of development in the Nigerian business
sector and inter-personal communication. However, the telephones have their challenges such as
underperformance of some components, for example, the battery. Although replacement batteries are available
in the market, under performance has always been the complaint of mobile phone users. This paper reports the
empirical performance of a sample of mobile phone batteries. The performance tests carried out included
determination of the battery capacity (Ahr rating), measurement of the battery’s talk time, self-discharge test and
ohm test. These tests were carried out using Cadex C8000 which is an advanced programmable battery testing
system. From the results obtained, it is concluded that batteries which came along with newly purchased mobile
phones perform better than replacement batteries obtained from mobile phone accessory shops. This confirms
the claim of consumers on the underperformance of replacement batteries; therefore, there is need for standard
in terms of mobile phone batteries imported into Nigerian market. This ensures better performance of mobile
phone batteries, value for the money spent to purchase the batteries and reduction of the adverse environmental
effects associated with the disposal of those batteries.
Keywords- Mobile phone, Battery capacity, Cadex C8000, Talk time, Performance.
1. Introduction
Cell phone is also known as mobile phone; the name
mobile indicates that the phone does not have to be
stationed in one location. These phones operate without a
cord of the necessity of a home base. It is easy to be
carried by the user and is used to send and receive calls
among many other applications [1]. Mobile phones are
equipped with a wide range of applications for both work
and play, and for communicating with smart networks.
The use of mobile phones has now been integrated into
human lives; it has become a general populace item that
cannot be done without. The continuous use of a mobile
phone has been made possible by the components
integrated into the device such as resistors, capacitors,
diodes, inductors, transistors, integrated circuit (IC) and
battery, to mention but few. The battery in a mobile
phone serves as an energy storage device.
The tremendous increase in the applications
running on mobile phones means more energy is required
from the energy storage device (Battery). The increase of
mobile phone users and usage has sprung replacement
parts manufacturers and retail shops, most especially for
the battery, which is a frequently failed part. As different
companies manufacture batteries, there are bound to be
differences in the batteries’ quality and reliability in
terms of meeting the need for powering the device, as
may be claimed by those manufacturers. A challenge of
meeting the need of users has been observed to lead to an
individual having more than one battery for a mobile
phone.
As a new mobile phone usually comes with one
battery, replacement batteries are also available in the
market for phones whose batteries are no longer good.
The replacement batteries are not necessarily
manufactured by the mobile phones’ manufacturers and
their economic values are not the same, as the
replacement batteries are also of different prices. The
choice of purchase is a function of users’ financial
buoyancy and usage experience.
Improper disposal of batteries cause harm to the
environment and the health of the consumers. Although
Li-Ion batteries which are used in modern mobile phones
are free of heavy metals (lithium has a low atomic
number), lithium's high degree of chemical activity can
create environmental problems. When exposed to water,
which is present in most landfills, the metal can burn,
causing underground fires that are difficult to extinguish.
Landfill is not sustainable; dumping mobile phone
batteries creates long term pollution risk to the
environment. Since hundreds of millions of mobile
phones batteries and their replacements are in use in
Nigeria, there is a high risk of hazard caused to the health
of the consumers and the environment if the batteries are
improperly disposed.
This study therefore focuses on testing the
performance of mobile phone batteries; comparing the
manufacturers’ specifications with empirical results. This
will help to identify batteries that do not meet up with
specifications, thus controlling the influx of substandard
batteries in the country. This results in better performance
The•Fourth•International•Renewable•Energy•Congress•
December•20-22,•2012•–•Sousse,•Tunisia•
849•
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IREC2012-EMS-120/O
of the batteries and consequently, customers’ satisfaction.
It guarantees that Nigerians purchase durable batteries
which have the performance stated on their labels. Also,
it minimizes the adverse environmental effects of
disposing the batteries.
2. Theory
A battery stores electrical energy and delivers it through
an electro-chemical reaction. A battery is made up of
electro-chemical cells. An electrochemical cell consists of
a cathode and an anode which are separated by an
electrolyte. Electric current is created as a result of the
flow of electrons from the anode to the cathode. Primary
cells (or batteries) are used once and discarded while
secondary cells (or batteries) are rechargeable and can be
used several times.
The major types of rechargeable batteries
include: Lead Acid, Nickel Cadmium (NiCd), Nickel
Metal Hydride (NiMH) and Lithium Ion (Li-Ion).
Lithium-Ion batteries are the most advanced and most
expensive batteries used in mobile phones today. They
are commonly used in mobile phones because they have
excellent power/weight ratio, longer talk time and do not
experience “memory effect”. Memory effect is a
condition whereby rechargeable batteries lose their
maximum energy capacity if they are not allowed to
deeply discharge before being recharged.
Figure 1 illustrates the energy and power
densities of lead acid, nickel-cadmium (NiCd), nickel-
metal-hydride (NiMH) and the Li-ion family (Li-ion).
Specific energy is the capacity a battery can hold in watt-
hours per kilogram (Wh/kg); specific power is the
battery’s ability to deliver power in watts per kilogram
(W/kg) [2].
(Source:
http://batteryuniversity.com/learn/article/global_battery_
markets)
Figure 1: Specific energy and specific power of
rechargeable batteries
2.1 Lithium ion battery technology
Pioneer work with the lithium battery began in 1912
under G.N. Lewis but it was not until the early 1970s
when the first non-rechargeable lithium batteries became
commercially available. Lithium is the lightest of all
metals, has the greatest electrochemical potential and
provides the largest energy density for weight. Attempts
to develop rechargeable lithium batteries failed due to
safety problems. Because of the inherent instability of
lithium metal, especially during charging, research
shifted to a non-metallic lithium battery using lithium
ions. Although slightly lower in energy density than
lithium metal, lithium-ion is safe, provided certain
precautions are met when charging and discharging. In
1991, the Sony Corporation commercialized the first
lithium-ion battery. Other manufacturers followed suit
[3].
Rechargeable lithium batteries involve a
reversible insertion/extraction of lithium ions (guest
species) into/from a host matrix (electrode material),
called lithium insertion compound, during the
discharge/charge process. The lithium insertion/extraction
process occurring with a flow of ions through the
electrolyte is accompanied by the reduction/oxidation
reaction of the host matrix combined with a flow of
electrons through the external circuit. The name of
lithium-ion battery is usually determined by cathode
material, for example, lithium iron phosphate, and lithium
cobalt battery [4]. The principle behind the chemical
reaction in the lithium ion battery is one where the
lithium in the positive electrode lithium cobalt oxide
material is ionized during charge, and moves from layer
to layer in the negative electrode. During discharge, the
ions move to the positive electrode and return to the
original compound. The chemical reactions for charge
and discharge are as shown below [5]:
Positive electrode
ଶ ֎ ଵି୶ଶ ା ି (1)
Negative electrode
ା ି ֎ ୶ (2)
Battery as a whole
ଶ ֎ ଵି୶ଶ ୶ (3)
3. Methodology
Seven mobile phone batteries were subjected to
performance tests. Batteries A1, A2 and A3 were
batteries used in mobile phones of a manufacturer;
batteries B1 and B2 were used in mobile phones of
another manufacturer while batteries C1 and C2 were
used in mobile phones of yet another manufacturer. A1,
B1 and C1 were batteries that came along with newly
purchased mobiles while A2, A3, B2 and C2 were
֎
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Charge
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hole
Discharge
ଶ
֎
ଵ
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୶
Discharge
֎
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Discharge
The•Fourth•International•Renewable•Energy•Congress•
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replacement batteries for the phones. Battery A3 was
purchased for half price of Battery A2. Listed in table 1
are the batteries’ specifications:
Table1: Specifications of the batteries tested
Battery
A1
A2
A3
B1
B2
C1
C2
Battery that
came along
with newly
purchased
mobile
phone
–
BL-5CB
Replacement
battery
–
BL
-5C
Replacement
battery
–
BL
-5C
Battery that
came along
with newly
purchased
mobile
phone
–
AK
Replacement
battery
–
AK
Battery that
came along
with newly
purchased
mobile
phone
–
BL-6GT
Replacement
battery
–
BL
-6GT
Battery
Chemistry
Li-Ion
Li-Ion
Li-Ion
Li-Ion
Li-Ion
Li-Ion
Li-Ion
Ahr Rating
800mAh
1020mAh
1020mAh
800mAh
800mAh
1800mAh
1800mAh
Voltage
Rating
3.7V
3.7V
3.7V
3.7V
3.7V
3.7V
3.7V
Energy
Rating
3.0Wh
3.8Wh
3.8Wh
2.96Wh
2.96Wh
6.66Wh
6.66Wh
Country
Manufactur
ed
China
Hungary
Hungary
China
China
China
-
The batteries were subjected to performance tests to
ascertain their practical performances as compared to
their specifications. Cadex C8000, an advanced
programmable battery testing system was used to
measure the performances of the mobile phone batteries.
The tests conducted include [6]:
i. Determination of the battery capacity (Ahr
rating): The prime program is used to determine the
actual capacities of the batteries. The program also
prepares new or stored batteries for use. A new or
stored battery may require several charge/discharge
cycles to form the cells to achieve peak performance.
The program cycles (discharges and charges) the
battery until the difference between capacities from
one cycle to the next is less than 5%. Up to four
cycles if the 5% capacity difference is not reached.
This allows for batteries that cannot accept a full
charge on the first cycle. If the battery is fully
discharged, the program starts with a charge. No
reconditioning is applied. Some batteries may require
several Prime cycles to fully form the cells.
ii. Self-Discharge Test: Self-discharge program
Identifies the self-discharge or the amount of charge
a battery loses if it is left alone for a period of time.
The standard time is 24 hours. The battery is
discharged for 10-minutes before charged and
discharged to obtain its first capacity. The battery is
then charged and left for a 24-hour rest period.
During this time, the battery loses energy through
self-discharge. After 24 hours, the battery is
discharged to determine the second capacity. The
difference between the second and first capacity is
the self-discharge rate.
iii. Measurement of the battery’s talk time: Simulated
GSM or CDMA discharge pulse is used to determine
the battery’s talk time. The battery is charged, the
program then discharges the battery using the GSM
or CDMA discharge pulse until it is fully discharged
(i.e. the end-of-discharge setting in the C-Code is
reached). A full charge is then applied to complete
the program.
iv. Ohm Test: This program is similar to the IEC “DC”
method of resistance measurement. It provides an
estimate of the battery capability to handle load. The
program tests the battery’s resistance and compares
the result with the battery’s OHMTEST SETPOINT.
If the result is above this threshold, the program fails
the battery.
4. Results and discussion
4.1 Determination of the battery capacity (Ahr
rating)
Table 2 shows the measured capacities of the batteries
using the prime program. The batteries were discharged
to obtain the first capacity; then they were charged and
discharged to determine the second capacity (the first
capacity is the capacity after the first discharge while the
second capacity is the capacity after the second
discharge). The charge and discharge cycle was repeated
until the difference between capacities from one cycle
and the next was less than 5%.
The•Fourth•International•Renewable•Energy•Congress•
December•20-22,•2012•–•Sousse,•Tunisia•
851•
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IREC2012-EMS-120/O•
Table 2: Capacities of the batteries
Battery
A1
(BL-5CB)
A2
(BL-5C)
A3
(BL-5C)
B1
(AK)
B2
(AK)
C1
(BL-6GT)
C2
(BL-6GT)
Ahr Rating (mAh)
800
1020
1020
800
800
1800
1800
1st Capacity (%)
40
53
3
55
3
53
1
2nd Capacity (%)
100
93
17
97
17
96
3
Final Capacity (%)
100
89
18
97
17
95
3
Actual Ahr Capacity
Available (mAh)
800
907.8
183.6
776
136
1710
54
Figure 2: Graphical analysis of the determination of the
capacity of battery A1
Battery A1 (battery that came along with newly
purchased mobile phone) had the highest capacity of
100% among batteries A1, A2 and A3. This means that
the true capacity of the battery was exactly what was
stated in its specification (800mAh). Battery A2
(Replacement battery) had 89% as its true capacity. This
implies that the Ah capacity obtainable from the battery
was 907.8mAh as compared to its specification
(1020mAh). The actual capacity of Battery A3
(Replacement battery) was 18% which means 183.6mAh
was obtainable from the battery instead of 1020mAh in
its specification.
Similar trend was observed in the remaining
batteries with Battery B1 (battery that came along with
newly purchased mobile phone) having a capacity of 97%
compared to Battery B2 (replacement battery)’s capacity
of 17%. Also, Battery C1 (battery that came along with
newly purchased mobile phone) had a capacity of 95%
while Battery C2 (replacement battery) had a very poor
capacity of 3%.
The table also shows that the capacities of the
batteries after their first discharge were low. This is
because lithium-based battery chemistries should not be
stored at full charge state so as to minimize age-related
capacity loss. Hence, new batteries should be charged to
full capacity before use. Moreover, lithium-based battery
chemistries should not be stored at too low state-of-
charge so as to keep the battery in operating condition
and allow self-discharge.
4.2 Self-discharge test
The batteries were charged and discharged to obtain their
capacities (first capacity). The batteries were then
charged and left for a 24-hour rest period after which the
batteries were discharged to determine their capacities
(second capacity).
Table 3: Self-Discharge test results
Battery
A1
(BL-5CB)
A2
(BL-5C)
A3
(BL-5C)
B1
(AK)
B2
(AK)
C1
(BL-6GT)
C2
(BL-6GT)
Ahr Rating (mAh)
800
1020
1020
800
800
1800
1800
1st Capacity (%)
99
94
23
97
19
95
3
2nd Capacity (%)
99
93
22
96
18
95
3
Capacity loss (%)
0
1
1
1
1
0
0
Ahr Capacity Lost (mAh)
0
10.2
10.2
8
8
0
0
The•Fourth•International•Renewable•Energy•Congress•
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IREC2012-EMS-120/O
Figure 3: Graphical analysis of self-discharge test for
battery A1
From Table 3, during the rest period, battery A1 did not
lose energy through self-discharge while Batteries A2 and
A3 lost 1% of their energy capacity as a result of self-
discharge. Batteries B1 and B2 lost 1% of their capacities
while batteries C1 and C2 did not lose their capacities to
self-discharge. According to Cadex, self-discharge
increases with age, cycling and elevated temperature. A
battery should be discarded if the self-discharge reaches
30 percent in 24 hours.
4.3 Measurement of the battery’s talk time
To determine the batteries’ talk time, simulated GSM and
CDMA discharge pulses were used.
Table 4: Batteries’ talk time
Battery
A1
(BL-5CB)
A2
(BL-5C)
A3
(BL-5C)
B1
(AK)
B2
(AK)
C1
(BL-6GT)
C2
(BL-6GT)
GSM
Capacity (%)
98
98
25
97
24
94
13
Talk time
(mins)
118
136
34
117.5
29.5
227
32.5
CDMA
Capacity (%)
100
100
27
98
22
94
13
Talk time
(mins)
124
159
43
123
28.5
269
39.5
(i) (ii)
Figure 4: Graphical analysis of battery A1’s talk time using (i) GSM and (ii) CDMA discharge pulse
From Table 4, batteries A1 and A2 showed good
capacities in the test while the capacity of battery A3 was
very low. Battery A1’s talk time seemed lower than that
of battery A2. This was because battery A1 had a lower
Ahr rating (800mAh) compared to battery A2
(1020mAh). Batteries B1 and C1 which were batteries
that came along with newly purchased mobile phones had
good results while replacement batteries B2 and C2 had
poor results.
Talk time can differ because they are dependent on the
mobile phone battery, mobile phone, mobile phone
features, service provider, network conditions, strength of
network signals, etc.
4.4 Ohm Test
The ohm test measures the resistance of the battery which
is an estimate of the battery capability to handle load.
Table 5: Resistances of the batteries
The•Fourth•International•Renewable•Energy•Congress•
December•20-22,•2012•–•Sousse,•Tunisia•
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Battery
A1
(BL-5CB)
A2
(BL-5C)
A3
(BL-5C)
B1 (AK)
B2 (AK)
C1
(BL-6GT)
C2
(BL-6GT)
Resistance (mOhm)
144.40
155.70
222.40
218.00
218.30
141.30
220.00
Figure 5: Graphical analysis of ohm test for battery A1
Unlike analog portable devices that draw a steady
current, the digital equipment loads the battery with short,
heavy current spikes. As a result, one of the requirements
of a battery for digital applications is low internal
resistance. The internal resistance is the gatekeeper that,
to a large extent, determines the runtime. The lower the
resistance, the less restriction the battery encounters in
delivering the needed power spikes. A high mW reading
can trigger an early 'low battery' indication on a
seemingly good battery because the available energy
cannot be delivered in the required manner and remains
in the battery [7].
From Table 5, among batteries A1, A2 and A3,
battery A1 had the lowest internal resistance while
battery A3 had the highest. Consequently, battery A1 had
the best load handling capability. Battery B1 had a high
internal resistance but it was a little better compared to its
replacement battery B2. Battery C1 showed good results
while battery C2’s result was poor.
5. Conclusion
Batteries A1, B1 & C1 which came along with newly
purchased mobile phones had better performance results
than replacement batteries A2, A3, B2 & C2, and they
conformed to their stated manufacturer’s specifications to
a large extent. This verifies some users’ complaints about
their dissatisfaction with the performances of replacement
batteries when compared to the batteries that come along
with newly purchased mobile phones. Moreover, cost is a
major factor, as Battery A3 which was a replacement
battery bought at half the price of Battery A2 performed
poorly when compared to Battery A2.
Hence, there is need to set up standards for mobile
phone battery and create policy framework to regulate
imported mobile phone battery. This ensures better
performance of mobile phone batteries, value for the
money spent to purchase the batteries and reduction of
the adverse environmental effects associated with the
disposal of those batteries.
6. References
[1] O. Krejcar, “Testing the Battery Life of Mobile
Phones and PDAs” 2011 International Conference
on Software and Computer Applications, IPCSIT
vol.9 (2011) © (2011) IACSIT Press, Singapore.
[2] Battery University, “Global Battery Markets” See
http://batteryuniversity.com/learn/article/global_batt
ery_markets (Accessed August, 2012).
[3] Battery University, “Is Lithium-ion the Ideal
Battery?” See
http://batteryuniversity.com/learn/article/is_lithium_
ion_the_ideal_battery (Accessed July, 2012)
[4] P. Tao, “Potential economic and environmental
advantages of lithium-ion battery manufacturing
using geothermal energy in Iceland” Thesis
submitted to the School of Science and Engineering
at Reykjavík University, MSc of Sustainable
Energy, 2011.
[5] Panasonic, “Lithium Ion Batteries”, 2007. See
http://industrial.panasonic.com/www-
data/pdf/ACA4000/ACA4000PE3.pdf (Accessed
July, 2012).
[6] C8000 Battery Testing System User Manual (V2.x)
Cadex® Electronics Inc. Part Number: 89-207-
3033, Document Number: PSMAN0056 Rev 2,
2010.
[7] Battery University, “How does Internal Resistance
affect Performance?” See
http://batteryuniversity.com/learn/article/how_does_
internal_resistance_affect_performance (Accessed
July, 2012).