Many of us notice that the efficiency of the rechargeable battery that we use on a daily basis, whether in our phones, laptop, or other devices, decreases significantly after a period of use, so that it no longer lasts for the same period as it was when it was new, but the battery charging became fast and lasts for a time Less, and it may eventually lead to complete battery damage. This may be due to reasons related to manufacturing quality sometimes, but even if the battery is produced by a reputable brand, the reason may be due to the nature of some types of batteries such as lithium-ion batteries that are used in most smartphones and laptops today, which degrade with use along with some practices faulty batteries while using those batteries.
In
this context, let us in this article review some of the most important reasons
for the low efficiency of the rechargeable battery, and ways to avoid them to
keep the battery in good condition for as long as possible.
First, the types of rechargeable batteries
At
the outset, we would like to point out that this article is not concerned with
smartphone batteries, but rather rechargeable batteries as a whole. There are
many types of rechargeable batteries, each of which has a different use and
life span.
In
general, any battery consists of one or more cells and its main function is to
store electrical energy and then re-discharge it for use in operating various
devices and equipment when needed. The first battery that came to existence was
invented by the Italian physicist Alessandro Volta in the year 1800, which was
a simple battery consisting of two electrodes and an electrolyte, and chemical
reactions take place inside the battery cell to allow electrons to flow through
the electrolyte from its positive electrode to the negative electrode, which
leads to the negative electrode of the cell, to A voltage is generated that
passes an electric current inside the battery.
Batteries
are divided into two main types, one of which is non-rechargeable (which is not
the topic of our discussion today), and the second is the rechargeable type,
which includes many sub-types, including:
Nickel-cadmium batteries
The
nickel-cadmium battery is one of the oldest types of rechargeable batteries in
use, which is still in use today. The possibility of unloading and charging it
once a day for three years before it deteriorates.
Nickel hydride batteries
This
is a relatively new type of nickel-hydrogen battery. The battery, despite its
high price, has a long life span of up to 1,000 charge cycles, has a much
higher energy storage capacity than nickel-cadmium batteries, and is used
especially in satellites and space applications.
Lithium-ion batteries
Lithium-ion
batteries are the most widely used today in electronic devices such as
smartphones and laptops, despite their high price, which is about 40% more than
nickel batteries, they are characterized by their small size and large
capacity, and the possibility of obtaining very high voltages as they provide
what It reaches 3.6 volts, which is equivalent to three times the voltage
provided by nickel-cadmium batteries and nickel-hydride batteries, and
lithium-ion batteries do not suffer greatly from some of the problems found in
nickel batteries such as memory effect and self-discharge as will be shown in
the following lines.
Second, the causes of deterioration of rechargeable batteries
1) Memory Effect
This
phenomenon, known as the "memory effect", occurs in some rechargeable
batteries such as nickel-cadmium and nickel-hydride batteries, when the user
recharges the battery before it is fully discharged, which may cause the
battery to form a form of memory that makes it visualize The same amount of
energy is required to fill the battery's capacity every subsequent charge,
which causes it to repeat the same incomplete charging cycle the next time it
is recharged.
The
memory effect also occurs in some battery cells when the metal around the
battery electrodes reacts with the electrolyte to form some salts. From there
the process of recharging, and both the voltage and current of the charge, in
addition to the temperature.
So,
if you use nickel-cadmium batteries, the best way to avoid the memory effect is
to constantly calibrate the battery so that you discharge it from energy to
contain only 1 volt per cell, and then recharge it completely. It is also
recommended to store it away from high temperatures and humidity, but it should
be kept In a cool dry place to protect it from damage.
2) Full charge and full discharge
Some
think that it is possible to maintain a rechargeable battery in good condition
by charging it to full power, i.e. 100%, and then using it until it runs out of
power completely, i.e. up to 0% power. Well, this might be true for some kind
of older battery types, but it doesn't apply to newer types of batteries like
the lithium-ion battery found in most smartphones, whose internal components
are under the most stress if they're fully charged or completely discharged.
That the increase in pressure or heat exposes it to combustion or damage.
Lithium-ion
batteries, as we mentioned before, do not suffer from the memory effect as it
does in nickel-cadmium batteries, and therefore; The solution to maintaining
the efficiency of the lithium-ion battery for a longer life is to charge it
80-90% and use it, then start recharging the battery before the percentage of
energy stored in it drops to about 20%.
3) Overcharging
Many
users leave their phones plugged in for hours even after the battery is 100%
charged, thinking that there is no danger of that.
In
fact, there are some phones and advanced computers that are already equipped
with a feature that enables them to avoid overcharging, that is, they prevent
the flow of more electricity to the battery poles automatically once the stored
energy reaches its maximum limits and the charging is complete, or they are
equipped with an adaptive charging feature, which works on Distributing energy
charge levels to the battery at intervals over a longer period of time to slow
down the charging process during night hours or periods of non-use until the
user is able to unplug the phone.
Such
methods guarantee the safety of the user, but what if these protections fail to
prevent the continued flow of electricity after charging is complete? What
about the effect of this on the efficiency and life of the battery?
When
a lithium-ion battery is connected, for example, to an electrical socket in
order to charge it, the battery will draw a constant current until the value of
the voltage inside the cells reaches 4.2 volts, then the voltage will be
stabilized after that and the battery will continue to be charged with power
for a certain period until the charging is complete. In the event that the
electricity is not disconnected after the charging process is completed, more
electrical energy will continue to flow into the battery, which will cause an
increase in the value of the voltage inside the cells, which will reduce the
efficiency and life of the battery.
The
excess energy will also result in the generation of more and more heat, which
affects the chemical reactions that take place inside the cells, creating
unstable chemical conditions inside the battery that may result in the leakage
of some gases in some types of batteries such as the lithium polymer battery,
and high pressure inside the battery. All of this reduces the life and
efficiency of the battery and may cause it to burn out or damage it completely.
An
increase in voltage and an increase in temperature as a result of overcharging
may also cause the battery to explode or burn in some rare cases, which poses a
danger to the user, and therefore care should always be taken to disconnect
power from rechargeable batteries when fully charged.
4) Self-discharge
The
phenomenon of self-discharge occurs in rechargeable batteries when chemical
reactions that occur inside the battery between the disconnected electrodes
reduce the amount of electrical charge stored inside the battery when it is not
in use, which affects the ability of the battery to reach a state of full
charge when in use, and reduces the life Its default overall.
The
rate at which a battery self-discharges depends on several factors such as
battery type, state of charge, charging current, and ambient temperature.
Lithium-ion batteries suffer from the problem of self-discharge to a lesser
extent compared to their counterparts of other types, as they self-discharge at
a rate of about 2-3% per month, while nickel-cadmium batteries experience a
self-discharge rate of 15-20% per month, and nickel-hydride 30 batteries
self-discharge at a rate of 30 % per month except for low self-discharge nickel
hydride batteries, which are constantly charged so that their self-discharge
rate ranges between 2-3% per month.
Storing
rechargeable batteries at lower temperatures reduces self-discharge rates,
conserving the initial energy stored within the battery.
5) Overheating
Operating
the rechargeable battery at high temperatures reduces the battery's electrical
resistance, which is the impedance experienced by electric current as it flows
between the poles, allowing the battery to supply your device with more power,
but what about the effect on the battery's efficiency and life?
Of
course, the chemical reactions that occur inside the battery are affected by
the ambient temperature as we mentioned before, especially the increase in
temperature, which reduces the battery life and the number of possible charging
cycles before the battery is damaged. Celsius loses about 40% of its life if it
is operated at a temperature of 11.46 degrees Celsius.
Most
rechargeable battery manufacturers recommend that their products be used at or
around room temperature, around 20-70°C. As operating or charging the battery
at different temperatures outside this range will lead to a significant
difference in performance when operating the battery, and we can observe this
difference in operation ourselves between a battery operating at low
temperatures and another battery operating at high temperatures.
6) Extremely low temperature
We
also knew that the ambient temperature has a significant impact on the life of
the battery and that its rise will reduce the electrical resistance inside the
battery; Thus, the opposite is true, meaning that operating the rechargeable
battery in extremely low temperatures and extreme cold will lead to an increase
in the electrical resistance inside it, and this will reduce the amount of
stored energy that the battery will supply to your device, which means that the
battery efficiency will decrease and the operating life will be reduced every
time before the charge runs out.
But
this will also increase the number of charge cycles or the times you can charge
and discharge your battery before it completely wears out, meaning the reduced
operating time and efficiency caused by a significant drop in temperature will
extend the life of the battery.
7) Using an inappropriate charger
Using
the right charger to charge your battery is very important to maintain its efficiency
and protect it from damage, as the charger output voltage used in the charging
process must match the battery voltage, and each of them must be equal in the
ampere-hour flow rate to avoid the problem of overcharging.
Third, tips to preserve the battery life in your devices
● To avoid decreasing the efficiency of your device's battery due to the effect
of memory if it is of the nickel-cadmium type, you must discharge it from power
almost completely, then recharge it completely. It is also recommended to store
it away from high temperatures and humidity and keep it in a dry and cool place
to protect it from damage.
● If your device uses a lithium-ion battery, you should use it until its capacity
drops to 20% of its capacity, and then recharge it until the energy stored in
it reaches about 80-90% of the battery capacity.
Overcharging
the battery should be avoided by charging it using a compatible charger to
avoid charging it with a voltage higher than the rated voltage, and not leaving
it connected to the power socket for long periods after the charging process is
complete, and lithium-ion batteries can be partially charged at intervals.
● You should avoid using and charging the device’s battery in extremely high or
very low temperatures, and try to use it at temperatures close to room
temperature as much as possible. The phone is in one of the pockets close to
your body to keep the battery at a cool temperature. If you are in very hot
weather, make sure to place or use your phone near the air conditioner to bring
it down as much as possible to room temperature.