Battery
Objective of the experiment:
1- Learn the principle of It is operation
2- Learn the parts of battery
3- Learn how to check the battery
❖battery working
The chemical reactions in a battery involve the flow of electrons
from one material (electrode) to another, through an external circuit.
The flow of electrons provides an electric current that can be used
to do work
• battery capacity
Battery capacity is measured in milliamps × hours (mAH). For
example, if a battery has 250 mAH capacity and provides 2 mA
average current to a load, in theory, the battery will last 125
hours. In reality, however, the way the battery is discharged has
an impact on the actual battery life
• battery Check:
1-Check the solution by the hydro-meter:
By placing the hydrometer device in the entrance to the battery to be
filled with the solution and then the solution is judged according to the
device's level
If the gradient in the green zone indicates that the density is good, either
if the solution is in the white zone, it indicates that the solution needs a
liar However, if the staging reaches the black area, this indicates the
powerlessness of the battery.
2 - Testing the capacity of battery (voltage difference):
Via the voltmeter
• If the result of the test between (10.8-12.6) v, the battery is good and
able to operate the vehicle.
• If the result of the test is less than 9.6 (v) the battery is not good and is
unable to operate the vehicle
❖magic eye in battery
The magic eye of a car battery is there to check on the condition of your
car battery. But how reliable is the magic eye indicator?
Sometimes you will come across a dead battery even when the magic eye
is telling you that the battery is healthy. Is this blog, we will explain to you
the function of the magic eye and why you should not depend solely on
its indicator.
• Anatomy of the Magic Eye
There are 4 main parts of a magic eye. Only the head and ball of the
magic eye are visible to you. The colored you see in the magic eye’s
indicator is actually a ball place inside the car battery.
• How Does the Magic Eye Work?
The colored ball will float when its surrounded by the well-charged
electrolyte in the car battery. On the other hand, the ball will sink when
the electrolyte is under-charged. Another phase is when the electrolyte is
at a low level where you will see a clear magic eye.
❖Charge the battery
Put on the appropriate safety gear. Safety is paramount any time you are
working on your vehicle. Start by putting on protective eyeglasses to
protect you from any falling material under the hood of the car, sparks or
battery fluid in the event the battery becomes compromised. You may also
want to wear gloves. Make sure the area you are working in is well
ventilated and lit sufficiently to allow you to see where you are going and
what you are working on.
• Gloves are not necessary but may protect your hands from small pinches
and cuts while working on your vehicle.
• Make sure there are no children in the area while you work on the
battery of a vehicle as sparks could fly if positive and negative cables
come into contact with one another.
• Determine what kind of battery you have. In order to properly charge
your battery, you must first identify the type of battery you have. You
can usually find this written somewhere on the battery, but you may
need to check the manufacturer's website if the label is too worn to
read or missing. You should also find out the voltage of the battery by
looking on the battery’s label or by checking in your vehicle owner's
manual. Types of batteries include:
• Wet cell batteries may be serviceable, which means there are things
you can do to help improve the charge and the life of your battery.
• VRLA Batteries (Valve Regulated Lead-Acid Battery) are completely
sealed and require no maintenance. These batteries come as Gel
Cell or Absorbed Glass Mat batteries and are less common in cars
unless purchased as an after-market modification.
• Get a car battery charger. Pick a charger that is appropriate for your
battery and purposes. Most chargers will work for all types of batteries
except Gel Cell batteries. There are fast chargers that can charge your
battery quickly or even provide you with a jump start, as well as "trickle"
chargers that provide a slow but longer lasting charge. Many newer
chargers come with a microprocessor to monitor how much the battery
has charged. These digital chargers will then stop the process
automatically when the battery is fully charged. Older, simpler chargers
must be stopped manually to prevent dangerous overcharging and
should not be left alone for extended periods of time while connected.
• Read the charger's instruction manual to make sure you are using your
particular unit correctly.
• Even new digital chargers should be monitored closely while charging to
ensure it functions properly and stops before over-charging the battery.
❖Disconnect and remove the battery from your vehicle if
necessary. It’s important to disconnect the battery before conducting
any repairs or maintenance on your vehicle. Most of the time you will
be able to charge the battery without taking it out of the car, but if
reaching the battery or fitting the charging cables in the engine bay or
trunk where the battery is located proves difficult, remove the battery
from the car completely while you charge it.
• If you are unsure where your battery is located, check the owner’s
manual for your vehicle. Some vehicles have the battery in the
trunk, while most have it under the hood.
• Disconnect the negative terminal first, then the positive when
removing a battery.
❖Clean the battery terminals. Any dirt or grime on the battery terminals
can prevent the charging cables from establishing a strong connection
to the battery, so it’s important to clean the terminals thoroughly. Use
baking soda and a wet cloth or a sandpaper pad to wipe away any
grime or rust. Make sure the terminals are bare metal before moving
on to the next step in order to ensure a strong charge. Sometimes you
may find the battery has a solid charge, but dirty terminals were
preventing the electricity from flowing.
• Do not touch the terminals with your bare skin, especially if there is
any white powder on them. This powder is usually dried sulfuric
acid, and it can burn your skin if you come in contact with it.
❖Place the charger on a stable surface. Never place the battery charger
directly onto the battery as it may connect the negative and positive
terminals, causing damage to the battery and charger and possibly
even starting a fire. Instead, place the charger on a stable surface as far
from the battery as the cables will allow. Before plugging the charger
into the wall, ensure the area is well ventilated by opening your garage
door or windows if you are indoors.
• Ensure the surface you place the charger on is sturdy and stationary
to prevent it from falling or disconnecting from the battery.
• Use the full length of the cables to separate the battery from the
charger as much as you can.
❖Connect the charger to the battery. Attach the black cable from the
charger with the negative (-) sign on it to the negative terminal on the
battery marked with the same symbol. Then attach the red cable with
the positive (+) sign to the positive terminal on the battery with the
corresponding symbol. Make sure to check the connections before
plugging in or turning on the charger, as mixing the positive and
negative terminals could result in damage to the battery or even a fire.
• Some cars may label the positive terminal with the letters POS
instead of a positive (+) symbol and NEG instead of a negative (-)
one.
• Ensure the cables are firmly attached to allow electricity to flow
from the charger to the batter
❖Set the charger. Digital chargers may indicate the existing voltage in
the battery and allow you to set the final voltage level, while older
models may simply allow for on and off settings. Speed chargers will
also allow you to choose the speed in which you want to charge the
battery (often depicted by a picture of a turtle for slow charges and a
rabbit for fast ones). A fast charge is good for a car battery that
recently died as a result of leaving your lights on or something to that
effect, while a battery that has been dead for some time may require
the slower charging method before the battery is usable again.
• If you can set the voltage the charger will stop on, set it to the
specified voltage on the battery or that you found in the vehicle’s
owner’s manual.
• Never set the charger to fast charge if you will be leaving the vehicle
unattended.
• You may want to leave the battery slow charging overnight to fully
charge it if it has been dead for some time.
❖Check the battery. After allowing the battery to charge, check it to
make sure it works. Some digital chargers will provide you with a
readout that will tell you if the battery is properly holding the charge
or if the battery will need to be replaced. This is often indicated by a
percentage like “100%” as in the battery is 100% charged. You may
also want to use a voltmeter to measure the voltage of the battery
once disconnected from the charger by touching the positive and
negative cables from the voltmeter to their respective terminals on the
battery. If the battery is still in the car, the easiest way to check it
might be to simply hook it up again and attempt to start the car. If the
voltmeter reads the number of volts that are appropriate for the
battery, the charger indicates it’s good, or the vehicle starts the battery
is sufficiently charged.
• If the voltmeter or charger indicate that the battery is bad or the
vehicle won’t start, there may be other issues to resolve or the
battery may need to be replaced.
