BATTERY Teknik Kendaraan Ringan Semester 2nd Class X Kompetensi Kejuruan SK-KD 15 TH

DIAGRAM ALUR PENCAPAIAN KOMPETENSI

What is the purpose of the battery in a car? Teknologi dan Rekayasa  Provide voltage and current for the starter motor  Provide voltage and current for the ignition system during cranking  Supplies all electrical power when the charging system is not operating  Acts as a voltage stabilizer for the charging system  Provides extra current for short periods of time while the charging system is catching up to a new load

Types of Batteries Teknologi dan Rekayasa IThe primary battery converts chemical energy to electrical energy directly, using the chemical materials within the cell to start the action. IThe secondary battery must first be charged with electrical energy before it can convert chemical energy to electrical energy. IThe secondary battery is frequently called a storage battery, since it stores the energy that is supplied to it.

DRY CELL Teknologi dan Rekayasa  Uses An electrolytic paste.  The electrolytic paste reacts with the electrodes to produce a negative charge on one electrode and a positive charge on the other.  The difference of potential between the two electrodes is the output voltage.

Lead Acid Battery Teknologi dan Rekayasa  Electrolyte for the most part distilled (pure) water, with some sulfuric acid mixed with the water.  Electrodes must be of dissimilar metals.  An active electrolyte.

Automotive Battery Types Teknologi dan Rekayasa  Gell Cell  Has 2 types of lead plates wound in a spiral  Uses an electrolyte in gell form  More expensive than lead acid  More durable than lead acid

Automotive Battery Connections Teknologi dan Rekayasa PPost Terminal UUsed in older cars SSide Terminal UUsed in newer cars LL Terminal UUsed in boats and equipment

Cells Teknologi dan Rekayasa  Positive electrode  Negative electrode  Electrolyte  Separator

The basic primary wet cell Teknologi dan Rekayasa  The metals in a cell are called the electrodes, and the chemical solution is called the electrolyte.  The electrolyte reacts oppositely with the two different electrodes  It causes one electrode to lose electrons and develop a positive charge; and it causes one other electrode to build a surplus of electrons and develop a negative charge.  The difference in potential between the two electrode charges is the cell voltage.

The Electrolyte Teknologi dan Rekayasa  When charging first started, electrolysis broke down each water molecule (H 2 O) into two hydrogen ions (H + ) and one oxygen ion (O -2 ).  The positive hydrogen ions attracted negative sulfate ions (SO 4 -2 ) from each electrode.  These combinations produce H 2 SO 4, which is sulfuric acid.

Electrolysis Teknologi dan Rekayasa  The producing of chemical changes by passage of an electric current through an electrolyte.

Specific Gravity Teknologi dan Rekayasa  Ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the two substances.  Example: It is the weight of the sulfuric acid - water mixture compared to an equal volume of water. Pure water has a specific gravity of 1,000.

Hydrometer Teknologi dan Rekayasa DDevice used to determine directly the specific gravity of a liquid.

Hydrometer Teknologi dan Rekayasa The chart below gives state of charge vs. specific gravity of the electrolyte. State of ChargeSpecific Gravity  100% Charged1.265  75% Charged  50% Charged  25% Charged  Fully Discharged1.110  These readings are correct at 75°F

Voltmeter = Hydrometer Teknologi dan Rekayasa If you are simply using an accurate voltmeter, along with occasional checks with your hydrometer, this chart should be helpful in determining your batteries state of charge. Charge Level Specific Gravity Voltage 2V n Voltage 6V n Voltage 12V n Voltage 24V n % % % % % n stands for nominal voltage

Series Connected Batteries Teknologi dan Rekayasa  Positive terminal of one cell is connected to the negative terminal of the next, is called a series connected battery.  The voltage of this type of battery is the sum of a individual cell voltages.

Parallel Connected Batteries Teknologi dan Rekayasa  Connect the negative terminal from one cell to the negative of the next cell  Connect the positive terminal to the positive terminal, is parallel connected.  Voltage remains constant and the current is cumulative.

Series-Parallel Connections Teknologi dan Rekayasa

Capacity Rating System Teknologi dan Rekayasa  The Society of Automotive Engineers (SAE) has established two ratings for domestic made batteries:  Reserve Capacity (RC)  Reserve capacity is the time required (in minutes) for a fully charged battery at 80°F under a constant 25 amp draw to reach a voltage of 10.5 volts  Cold Cranking Amps (CCA)  This rating measures the discharge lead (in amps) that a battery can supply for 30 seconds at 0°F (-17°C), while maintaining a voltage of 1.2 volts per cell (7.2 volts per battery or higher).

Capacity Rating System Teknologi dan Rekayasa RRC (Reserve Capacity) IIt determines the time in minutes a vehicle can be driven after the charging system fails TThe length of time a fully charged battery (at 80 ° F) can supply 25 Amps before the voltage falls below 10.5 Volts AAmpere Hour TThe amount of current a fully charged battery (at 80 ° F) can supply for 20 hours without having the voltage fall below 10.5 Volts

Capacity Rating System Teknologi dan Rekayasa Determining Battery Ratings  Most battery ratings are printed or stamped in the top of the battery  Most have 1 or 2 ratings

Capacity Rating System Teknologi dan Rekayasa Determining Positive and Negative  In a post type, the positive (or +) is larger than the negative post (or -)  In the side terminal, it is marked POS or + for positive and NEG or – for negative

Preventive Maintenance Teknologi dan Rekayasa  When the top of a battery is “dirty or looks damp.  Give a battery a general cleaning, use hot water (130° F to 170° F) with a neutralizer / detergent solution.

Preventive Maintenance Teknologi dan Rekayasa Corrosion  Corrosion causes many battery failures  Corrosion causes a barrier between the battery post and the cable  When there is a barrier, no electrons can flow  Even though the battery is fully charged, it won’t start the car Eliminating Corrosion WWash the top of the battery with hot water until all the corrosion is gone RRemove the negative cable, then the positive cable CClean the positive post with a battery cleaning brush, then the battery cable TThe corrosion is gone when the post and cable are shiny

Charging Teknologi dan Rekayasa CChemical reaction occur during charging. LLead sulfate on both plates is separated into Lead (Pb). SSulfate (SO4) leaves both plates. IIt combines with hydrogen (H) in the electrolyte to form sulfuric acid (H2SO4). OOxygen (O) combines with the lead (Pb) at the positive plate to form lead oxide (PbO2). TThe negative returns to original form of lead (Pb.

Charging Teknologi dan Rekayasa  Clean Battery Terminals.  Attach clamps to the battery in proper polarity.  Keep open flames and sparks away from battery.  Ventilate the battery well while charging.  The charge a battery receives is equal to the charge rate in amperes multiplied by the time in hours.  Measure the specific gravity of a cell once per hour during charging to determine full charge.

Charging Teknologi dan Rekayasa Overcharging RResults in warped or broken plates, damaged separators, severe shedding of the active materials pasted to the plates, and excessive loss of water, which cause plates to dry out. Ventilation Requirements TThe oxygen and hydrogen gases released during the gassing phase of a typical flooded lead-acid battery recharge can be dangerous if allowed to exceed 0.8 % (by volume) or 20 percent of the lower explosive range. Concentrations of hydrogen between 4 % and 74% are considered explosive (40,000 ppm and 740,000 ppm).

Jump Starting Teknologi dan Rekayasa  Be sure to turn off accessories.  Connect the red cable to the positive terminal on the good battery while the engine is running.  Connect the other end of the red cable to the positive terminal on the dead battery.  Then connect one end of the black cable to the negative terminal on the good battery.  Connect the other end of the negative cable to a known good ground in the vehicle with the dead battery.  After starting the vehicle with the discharged battery, allow the engine to return to idle speed.  Remove the negative jumper cable starting with the end that is connected to the vehicle ground  Remove the positive cable.

Checking the Battery Teknologi dan Rekayasa  If there is an indicator window, look at the color of it  Green indicates good, dark green means it needs a charge, and white or yellow means it needs to be replaced  Check the outside of the battery for cracks  Check the hold down for tightness  Check for cracked or broken cables

Checking the Battery Teknologi dan Rekayasa Voltage Tests – Open Circuit  Turn on the headlights for 2 minutes  Turn off the headlights and connect a voltmeter to the battery, red lead to positive, black to negative  If the battery is good, it will read above 12.2 volts  If below that, charge the battery  LOAD TESTING  Turn the Load Increase control until the ammeter reads 3 times the amp-hour (AH) rating or one- half the cold-cranking ampere (CCA) rating  Hold that reading for 15 seconds  Read voltmeter  A good battery will read at or above 9.6 volts  Battery should be at 70 ° F

Checking the Battery Teknologi dan Rekayasa Cable Corrosion Test  Using a voltmeter, hook the black lead to the negative post, and the red lead to the cable connector while turning on the headlights  Reading should be 0 volts

Teknologi dan Rekayasa Bibliography: Crown Battery Company

Thanks very much Presented by Aloysius Sudibyo SMK Negeri 1 Magelang