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  1. [31]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
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    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    اقتباس المشاركة الأصلية كتبت بواسطة eng_mechanic مشاهدة المشاركة
    شكرا للرقابه

    مشكوررررر اخى على ردك

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    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  2. [32]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    نبدا الموضوع السادس وسوف نتكلم عن الكتاوت
    Understanding Relays
    _____________________________
    -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_--_-_-_-_-_-_-_-_--_--

    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  3. [33]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    RELAYS
    Relays are used throughout the automobile. Relays which come in assorted sizes, ratings, and applications, are used as remote control switches. A typical vehicle can have 20 relays or more.




    RELAY LOCATIONS
    Relays are located throughout the entire vehicle. Relay blocks, both large and small, are located in the engine compartment; behind the left or right kick panels, or under the dash are common locations. Relays are often grouped together or with other components like fuses or placed by themselves.



    RELAY POSITION IDENTIFICATION
    Relay / Fuse block covers usually label the location and position of each fuse, relay, or fuse element contained within.




    RELAY APPLICATIONS
    Relays are remote control electrical switches that are controlled by another switch, such as a horn switch or a computer as in a power train control module. Relays allow a small current flow circuit to control a higher current circuit.
    Several designs of relays are in use today, 3-pin, 4-pin, 5-pin, and 6-pin, single switch or dual switches.



    RELAY OPERATION
    All relays operate using the same basic principle. Our example will use a commonly used 4 - pin relay. Relays have two circuits: A control circuit (shown in GREEN) and a load circuit (shown in RED). The control circuit has a small control coil while the load circuit has a switch. The coil controls the operation of the switch.




    RELAY ENERGIZED (ON)
    Current flowing through the control circuit coil (pins 1 and 3) creates a small magnetic field which causes the switch to close, pins 2 and 4. The switch, which is part of the load circuit, is used to control an electrical circuit that may connect to it. Current now flows through pins 2 and 4 shown in RED, when the relay is energized.



    RELAY DE-ENERGIZED (OFF)
    When current stops flowing through the control circuit, pins 1 and 3, the relay becomes de-energized. Without the magnetic field, the switch opens and current is prevented from flowing through pins 2 and 4. The relay is now OFF.



    RELAY OPERATION When no voltage is applied to pin 1, there is no current flow through the coil. No current means no magnetic field is developed, and the switch is open. When voltage is supplied to pin 1, current flow though the coil creates the magnetic field needed to close the switch allowing continuity between pins 2 and 4.








    NORMALLY DESIGN ID
    Relays are either Normally Open or Normally Closed. Notice the position of the switches in the two relays shown below. Normally open relays have a switch that remains open until energized (ON) while normally closed relays are closed until energized. Relays are always shown in the de-energized position (no current flowing through the control circuit - OFF). Normally open relays are the most common in vehicles; however either can be use in automotive applications.


    Normally Open (NO)

    Normally Closed (NC)

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    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  4. [34]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    NORMALLY CLOSED RELAYS
    The operation of a Normally Closed relay is the same to that of a Normally Open relay, except backwards. In other words, when the relay control coil is NOT energized, the relay switch contacts are closed, completing the circuit through pins 2 and 4. When the control coil is energized, the relay switch contacts opens, which breaks the circuit open and no continuity exists between pins 2 and 4.



    DE - ENERGIZED (OFF)

    ENERGIZED (ON)


    ACTUAL RELAY DESIGN
    Current flows through the control coil, which is wrapped around an iron core. The iron core intensifies the magnetic field. The magnetic field attracts the upper contact arm and pulls it down, closing the contacts and allowing power from the power source to go to the load.


    RELAY VARIATIONS
    Other relay variations include three and five pin relays. A 3-PIN relay instead of two B+ input sources, this relay has one B+ input at pin 1. Current splits inside the relay, supplying power to both the control and load circuits. A 5-PIN relay has a single control circuit, but two separate current paths for the switch: One when the relay is de-energized (OFF - no current through the control coil) and the other the energized (ON - current is flowing through the control coil). When the 5-PIN relay is de-energized (OFF), pins 4 and 5 have continuity. When the relay is energized (ON), pins 3 and 5 have continuity.



    3 - PIN
    4 - PIN
    5 - PIN



    ISO STANDARDIZED RELAYS
    ISO relays were designed to try and standardize relay connections, making it easier to test and design systems. ISO relays are currently used by almost all automotive manufacturers today. Both 4 and 5 pin designs are used in both standard mini and micro sizes. FYI: ISO is short for International Standard Organization.


    STANDARD MINI SHOWN



    STANDARD MINI ISO RELAYS TYPES
    Below are two popular standard MINI ISO relay configurations. The size of a ISO Standard MINI relay is a 1" square cube. Both 4 and 5 pins designs are used.


    5 PIN
    MINI RELAY








    4 PIN
    MINI RELAY









    ISO MICRO RELAY TYPES
    Below are two popular MICRO ISO relay configurations. The size of a ISO MICRO relay is a 1" x 1" x 1/2" square (1/2 as thick as a Mini relay). Both 4 and 5 pins designs are used.




    5 PIN
    MICRO RELAY











    4 PIN
    MICRO RELAY









    VOLTAGE SPIKES
    When the switch is closed (shown left), current flows through the coil from positive to negative as shown in red. This current flow creates a magnetic field around the coil. The top of the coil is positive, and the bottom is negative.

    When the switch is opened (shown on right), current stops flowing through the control circuit coil, and the magnetic field surrounding the coil cannot be maintained. As the magnetic field collapses across the coil, it induces a voltage into itself, creating a reverse polarity voltage spike of several hundred volts. Although the top of the coil is still 12 volts positive, the bottom of the coil produces several hundred positive volts (200+ volts or more); 200 is "more positive" and stronger than 12 volts, so current flows from the bottom of the coil up towards the top.
    VOLTAGE SUPPRESSION RELAYS
    Relays are often controlled by a computer. When relays are controlled by semiconductors such as transistors, they require some type of voltage suppression device. Solid state circuits are vulnerable to voltage spikes. Voltage spikes slam against transistors, destroying them. While some computer circuits have voltage suppression built inside the computer, others rely on voltage suppression from within the relay. High ohm resistors, diodes, or capacitors can be used for voltage suppression. Diodes and resistors are the most common. NOTE: Relays are usually clearly marked if a suppression diode or resistor are present.

    RELAYS WITH DE-SPIKING DIODES
    A de-spiking (clamping) diode is connected in parallel with the relay coil. It is in the reverse biased position when the relay is turned on; therefore no current will flow through the diode. When the relay control circuit is opened (turned OFF), current stops flowing through the coil, causing the magnetic field to collapse. The magnetic lines of force cut through the coil and induce a counter voltage (a voltage in reverse polarity) into the winding. The counter voltage begins to raise. When the bottom side of the diode sees .7 volts more positive voltage than the top, the diode becomes forward biased, allowing the excess voltage to pass, completing the circuit to the other end of the coil. The current flows around in the diode and coil circuit until the voltage is dissipated.

    RELAYS WITH DE-SPIKING RESISTORS
    High ohm resistors are sometimes used instead of diodes. A resistor is more durable than a diode and can suppress voltage spikes similar to a diode, but the resistor will allow current to flow through it whenever the relay is on. Therefore resistance of the resistor must be fairly high (about 600 ohms) in order to prevent too much current flow in the circuit. High ohm resistors are not quite as efficient at suppressing a voltage spike as diodes.

    CIRCUIT IDENTIFICATION
    Relays are easy to test but often misunderstood. Using a 4 pin relay for our example, we must first identify the pins. Some manufacturers place a diagram and pin ID on the outside of the relay case to show which pins are part of the control circuit and which pins are part of the load circuit.








    CONTINUITY CHECK FOR PIN ID
    If the relay is not labeled, use an ohmmeter and check to see which pins are connected to each other. You should typically find an ohm value of approximately 50 to 120 ohms between two of the pins. This is the control circuit. If the coil is less that 50 ohms it could be suspect. Refer to manual to verify reading. The remaining two pins should read OL (infinite) if it's a normally open relay, or 0 ohms (continuity) if it's a normally closed relay. If the readings are correct, proceed to the next test. Note: If none of the relay pins showed a coil value and all pins show OL or 0 ohms, the control coil is damaged and should be replaced.

    PRACTICAL TESTING
    Once the pins have been identified, energize the control circuit by supplying B+ to pin 1 and a ground to pin 3. A faint "click" will be heard; although this "click" means the switch has moved (closed), it does not mean the relay is good. The load circuit switch contacts could still be faulty (high resistance), and further testing is required. A common mistake technicians make is they hear a "click" and assume the relay is good. Take the extra step and verify operation.


    CAUTION
    Testing relays with built in clamping diodes require a special procedure. These relays are polarity sensitive; placing B+ to the wrong pin (backwards) while performing a practical test will forward bias the diode and damage the diode, thus destroying the protective quality of the diode.


    OPERATIONAL CHECK WITH TESTLIGHT
    Now start the second part of the test. Energize the relay (control side) by supplying B+ to pin 1 and a ground to pin 3. A click should be heard. With the relay still energized, supply B+ pin 2 of the load circuit. The test light will be on. De-energize (remove B+) the control circuit at pin 1; the test light at pin 4 should go off. A test light is preferred because a test light will draw current through the switch.


    CAUTION
    Testing relays with built in clamping diodes require a special procedure. These relays are polarity sensitive; placing B+ to the wrong pin (backwards) while performing a practical test will forward bias the diode and damage the diode, thus destroying the protective quality of the diode.


    OPERATIONAL CHECK WITH VOLTMETER
    A voltmeter can be substituted in place of a test light; however be aware if the contacts are partially burned, the voltmeter will show voltage indicating good contact even when bad. Remember high impedance digital voltmeters draw almost no current. Energize the relay (control side) by supplying B+ to pin 1 and a ground to pin 3. A click should be heard. With the relay still energized supply B+ to pin 2 of the load circuit. Connect the RED lead to pin 4 and the BLACK lead to ground. The voltmeter will indicate source voltage (12V). De-energize (remove B+) the control circuit at pin 1; the voltmeter should now read "zero". Re-energize the relay and the voltmeter should return to 12 volts.

    CAUTION
    Testing relays with built in clamping diodes require a special procedure. These relays are polarity sensitive; placing B+ to the wrong pin (backwards) while performing a practical test will forward bias the diode and damage the diode, thus destroying the protective quality of the diode.

    OPERATIONAL CHECK WITH AN OHMMETER
    An ohmmeter can also be used to test the load circuit, but the same problem as the voltmeter comes into play. Energize the relay (control side). Supply B+ to pin 1 and a ground (neg.) to pin 3. A click should be heard. Place the leads on an ohmmeter to across pin 2 and pin 4. Assuming it is a normally open relay the ohmmeter will indicate a complete circuit (close to zero -0 ohms). De-energize the control circuit at pin 1(remove B+). The ohmmeter should indicate OL (an open circuit - infinite). Re-energize the relay and the ohmmeter should return to "zero" ohms. Note: some manufactures provide a maximum ohm value when the switch contacts are closed, example 5 ohms max.

    CAUTION
    Testing relays with built in clamping diodes require a special procedure. These relays are polarity sensitive; placing B+ to the wrong pin (backwards) while performing a practical test will forward bias the diode and damage the diode, thus destroying the protective quality of the diode.


    OPERATIONAL CHECK FOR RELAY VOLTAGE SUPPRESSION DIODES
    An ANALOG OHMMETER must be used. This test cannot be performed with a digital meter. The analog meter sends out a higher voltage which is required to forward bias the diode. Place the ohmmeter across the control circuit and record reading. Reverse the leads and check the control circuit again. A functioning diode will be indicated by have two different readings. A faulty diode will have the same reading in both directions.

    Current from the ohmmeter flows through the control coil, in one direction. By reversing the leads, you send current in the opposite direction through the control coil. One of the two directions the diode will be forward biased(on), creating two paths for current thus lowering resistance. With the leads in the other direction, the diode in will be reversed biased (off) creating only one path, with higher resistance.



    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  5. [35]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    وبعد كدة ندخل فى الجد شوية

    ان شاء الله نبدا فى
    اساسيات البطارية
    Battery Basics

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    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  6. [36]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    THE AUTOMOTIVE BATTERY
    A lead-acid storage battery is an electrochemical device that produces voltage and delivers electrical current. The battery is the primary "source" of electrical energy used in vehicles today. It's important to remember that a battery does not store electricity, but rather it stores a series of chemicals, and through a chemical process electricity is produced. Basically, two different types of lead in an acid mixture react to produce an electrical pressure called voltage. This electrochemical reaction changes chemical energy to electrical energy and is the basis for all automotive batteries.








    THE PURPOSE OF THE BATTERY
    The battery supplies electricity when the:

    ENGINE IS OFF: Electricity from the battery is used to operate lighting, accessories, or other electrical systems when the engine is not running.
    ENGINE IS STARTING: Electricity from the battery is used to operate the starter motor and to provide current for the ignition system during engine cranking. Starting the car is the battery's most important function.
    ENGINE IS RUNNING: Electricity from the battery may be needed to supplement the charging system when the vehicle's electrical load requirements exceed the charging system's ability to produce electricity. Both the battery and the alternator supply electricity when demand is high.




    BATTERIES - Primary or Secondary
    Batteries can either be a primary cell, such as a flashlight battery once used, throw it away, or a secondary cell, such as a car battery (when the charge is gone, it can be recharged).
    PRIMARY CELL: Because the chemical reaction totally destroys one of the metals after a period of time, primary cells cannot be recharged. Small batteries such as flashlight and radio batteries are primary cells.
    SECONDARY CELL: The metal plates and acid mixture change as the battery supplies voltage. As the battery drains the metal plates become similar and the acid strength weakens. This process is called discharging. By applying current to the battery in the reverse direction, the battery materials can be restored, thus recharging the battery. This process is called charging. Automotive lead-acid batteries are secondary cells and can be recharged.



    BATTERIES - Wet or Dry Charged
    Batteries can be produced as Wet-Charged, such as current automotive batteries are today, or they can be Dry-Charged, such as a motorcycle battery where an electrolyte solution is added when put into service.
    WET-CHARGED: The lead-acid battery is filled with electrolyte and charged when it is built. During storage, a slow chemical reaction will cause self-discharge. Periodic charging is required. Most batteries sold today are wet charged.
    DRY-CHARGED: The battery is built, charged, washed and dried, sealed, and shipped without electrolyte. It can be stored for up to 18 months. When put into use, electrolyte and charging are required. Batteries of this type have a long shelf life. Motorcycle batteries are typically dry charged batteries.



    BATTERY CONSTRUCTION
    An automobile battery contains a diluted sulfuric acid electrolyte and positive and negative electrodes, in the form of several plates. Since the plates are made of lead or lead-derived materials, this type of battery is often called a lead acid battery. A battery is separated into several cells (usually six in the case of automobile batteries), and in each cell there are several battery elements, all bathed in the electrolyte solution.




    CELL OPERATION
    Two dissimilar metals placed in an acid bath produce electrical potential across the poles. The cell produces voltage by a chemical reaction between the plates and the electrolyte. The positive plate is made of reddish-brown material such as Lead Dioxide (PBO2) while the negative plate is made of grayish material called Sponge Lead (PB). The acid bath is a mixture of sulfuric acid and water cell electrolyte. Together a cell element is formed.



    CYCLING
    The battery stores electricity in the form of chemical energy. Through a chemical reaction process the battery creates and releases electricity as needed by the electrical system or devices. Since the battery loses its chemical energy in this process, the battery must be recharged by the alternator. By reversing electrical current flow through the battery the chemical process is reversed, thus charging the battery. The cycle of discharging and charging is repeated continuously and is called "battery cycling".




    DEEP CYCLING
    Although batteries do cycle continuously, they do not cycle deeply. Deep cycling is when the battery is completely discharged before recharge.

    Automotive batteries are not designed as deep cycle batteries. Automotive batteries are designed to be fully charged when starting the car; after starting the vehicle, the lost charge is replaced by the alternator. So the battery remains fully charged. Deep cycling an automotive battery will cause damage to the plates and shorten battery life.
    Marine or golf cart batteries (Deep Cycle Batteries) on the other hand are designed to be completely discharged before recharging. Because charging causes excessive heat which can warp the plates, thicker and stronger plate grids are used. Normal automotive batteries are not designed for repeated deep cycling and use thinner plates.




    CELL VOLTAGE
    Each cell element of the battery produces approximately 2.1 volts, regardless of the quantity or size of the plates. Automobile batteries have six cells that are connected in series, which produces a total voltage of 12.6 volts.


    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  7. [37]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    BATTERY CELL ELEMENT
    The key to battery operation is the cell element. Positive plates and negative plates are each connected together by separate plate straps. These groups of positive and negative plates are then placed alternately, separated by micro-porous separators. Assembled together, the plates and separators form a battery cell element. Grouping the plates in this way serves to enlarge the surface area between the active materials and the electrolyte, thus allowing a greater amount of electricity to be supplied. In other words, the battery capacity is increased because of the increase in surface area. More plate surface area means the battery can deliver more current.



    PLATES
    Battery plates are constructed of a lead alloy containing a percentage of either Antimony or Calcium. The plates are designed as a thin flat grid, grids crossing at right angles (shown below) or grids crossing diagonally at different angles which reduces internal resistance. The grid provides the necessary framework for active material to be pasted onto the plate, making either a positive or a negative plate. The active material on a charged positive plate is a reddish-brown Lead Dioxide (PBO2), while the active material on a charged negative plate is a grayish Sponge Lead (PB).



    GEL CELL BATTERIES
    A gel battery design is typically a modification of the standard lead acid automotive. A gelling agent is added to the electrolyte to reduce movement inside the battery case. Many gel batteries also use one way valves in place of open vents, this helps the normal internal gasses to recombine back into water in the battery, reducing gassing. The spiral design provides more plate surface area and closer plate spacing resulting in a lower internal resistance. This low resistance provides more power in a smaller battery case and the ability to recharge much faster.



    BATTERIES - Antimony, Calcium, or Gel
    Several variations of the Lead -Acid battery are used today. Variations to the battery plate material and electrolyte solution provide different battery characteristics. Construction is basically the same; however, the materials used are slightly different.
    1. Lead Antimony ( Most commonly used ).
    Is commonly used in conventional lead acid battery which uses lead antimony cell plates.

    Advantages:
    1. Longer service life than Calcium batteries.
    2. Easier to recharge when completely discharged.
    3. Lower cost.
    2. Lead Calcium ( AC Delco maintenance free batteries ).
    Is a maintenance free lead acid battery which uses lead calcium cell plates.

    Advantages:
    1. Larger electrolyte reserve area above the plates.
    2. Higher Cold Cranking Amp ratings.
    3. Little or No maintenance.
    3. Recombination (Gel Cell) ( Optima batteries and some others ).
    Is a completely sealed lead acid battery which uses an electrolyte that is a gel (solid) rather than a liquid.

    Advantages:
    1. No liquid electrolyte to spill or leak.
    2. Can be Deep Cycled several time without damage.
    3. Totally corrosion and maintenance free.
    4. Three to four times longer battery life than regular batteries.
    5. More plate surface and closer plate spacing provides a compact case size.


    LEAD ANTIMONY VS. LEAD CALCIUM
    Lead-Antimony Cast Grid
    Conventional Low-Maintenance batteries use grids of Lead-antimony which is readily available, inexpensive, easy to cast, and provide a rechargeable battery that offers optimum efficiency and low cost. Lead antimony is used in Low-Maintenance batteries.
    Such batteries are built to reduce internal heat and water loss. Battery construction provides a deeper well area to allow a slight water loss over the life of the battery. Under normal conditions, the addition of water should not be required.
    Lead-Calcium Grid
    The maintenance-free batteries, such as Delco Freedom batteries, uses calcium. The lead-calcium grid is strong, more resistant to corrosion as well as overcharging, gassing, water usage, and self-discharge, all of which shorten battery life in conventional lead-acid batteries. Lead calcium is used in Maintenance Free batteries. Battery construction provides a
    deeper well area to allow a slight water loss over the life of the battery. No provision for adding water to the cells is provided because the battery is sealed.


    ELECTROLYTE
    Battery electrolyte is a mixture of 64% distilled water (H20) and 36% sulfuric acid (SO4). Batteries today have an electrolyte with a specific gravity of 1.270 (at 20'C, 68'F) when fully charged. Specific Gravity is the weight of a given volume of liquid in comparison to the weight of the same volume of water. The higher the specific gravity of a liquid the denser (thicker) it is. Testing specific gravity will be discussed in the Battery Service Module.




    SPECIFIC GRAVITY OF ELECTROLYTE
    Specific gravity means exact weight. A "Hydrometer" or a "Refractometer" compares the exact weight of electrolyte with that of water. Electrolyte in a charged battery is stronger and heavier than electrolyte in a discharged battery. By weight, the electrolyte in a fully charged battery is about 36% acid and 64% water. The specific gravity of water is 1.000, and the specific gravity of sulfuric acid is 1.835, which means the acid is 1.835 times heavier than the water. The battery electrolyte mixture of water and acid has a specific gravity of 1.270 and is usually stated as "twelve and seventy."



    BATTERY SPECIAL HANDLING
    The electrolyte inside the battery is a mixture of sulfuric acid and water. Sulfuric acid is very corrosive and can cause severe injury to your skin and eyes. Always wear protective goggles, gloves, and apron while servicing the battery. If it gets on your skin, flush with a large quantity of water immediately; if it gets in your eyes, flush with large quantities of water immediately (a mild solution of baking soda and water will neutralize the acid) and seek medical attention as soon as possible.

    Because sulfuric acid will eat through clothing, it is advisable to wear proper work clothing when handling batteries. When charging the battery, hydrogen gas is released so it is extremely important to keep flames or sparks away from the battery to prevent explosion.



    BATTERY CASE
    The battery case holds the electrolyte and the individual battery cell elements. It is divided into six compartments or cells. The plates are raised up off the bottom of the case with ribs to prevent them from shorting out if any of the active materials (lead, etc.) should happen to fall from the plates. The case is made of polypropylene, hard rubber, and plastic base materials. Some battery manufacturers use translucent plastic cases which allow checking electrolyte level without removing vent caps
    . These cases often have "upper" and "lower" electrolyte level markers on the outside of the case.




    VENT CAPS
    Vent
    caps cover the holes that are used for adding electrolyte. They are also designed to separate the sulfuric acid mist and the hydrogen gas that forms when the battery charges. The caps are designed to the sulfuric acid mist to condense and drop back into the battery and allow hydrogen gas to escape through the vent holes to the atmosphere. Vent caps can cover each individual cell as shown below. Note:Many Gel Cell Batteries use a one way check valve enplane of vents.



    VENT CAP STRIPS
    Most batteries
    today use vent cap strips that cover multiple cells (shown below). The caps are are designed to allow hydrogen gas to escape and sulfuric acid mist to condense and drop back into the battery.



    BATTERY TERMINAL DESIGN
    Three design types of battery terminals are used; the Top (Post) Terminal, Side Terminal, and the "L" Terminal types. The top terminal design is the most popular among automotive batteries. Top post terminal batteries have tapered posts on the top of the battery. The side terminal design is used exclusively by General Motors, and the "L" terminal design is used in marine applications; both have internally threaded terminals.





    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  8. [38]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
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    BATTERY TERMINAL IDENTIFICATION
    Battery terminals are identified as either "positive" or "negative". Battery cases are marked with a "+" for the positive terminal, and a "-" on the negative terminal as shown below. The words "POS" or "NEG" are often used instead of the + or -. On top post terminal batteries, the positive post is slightly wider than the negative terminal post. This allow for easy identification.





    BATTERY TERMINAL CLAMPS
    Battery cable clamps are can be made of steel or lead depending on the manufacturer. In addition, they can be attached to the cable by either crimp or bolt and nut. A crimped one piece battery cable with clamp is the most common used today.


    STEEL


    LEAD




    BUILT IN SPECIFIC GRAVITY INDICATOR
    Most maintenance free batteries use a built in single ball hydrometer that measures specific gravity in one cell, which is located on the top of the battery.




    BATTERY HOLD DOWN / CARRIER
    Battery hold downs are used to stop the battery from vibrating, moving, or spilling over while the car is in motion. Vibration will cause the battery to fail prematurely. Excessive vibration or sharp movement will cause active material to fall off the plates ruining the battery. The battery must always be secured. Additionally, a battery carrier or tray underneath the battery aids in securing the battery to the vehicle.




    MANUFACTURER CODE / DATE CODE
    A manufacturer's code is stamped onto the battery case at time of its manufacture. This manufacturers code contains information as to the date of manufacture, type, manufacturing plant, etc.

    A two letter code ( B0, A9, etc.) is also placed on the battery to make it easier for resellers and consumers to identify the production date. The code is on a sticker affixed to the battery or hot-stampded into the case cover along the top edge. The first letter represents the month, and the second number represents the year. The picture below shows B9, which is February 1999. Fresh batteries are always the best. Refer to the battery vendor or supplier for this information.

    STICKER
    DATE CODES

    A = January
    B = February
    C = March
    D = April
    E = May
    F = June
    G = July
    H = August
    J = September
    K = October
    L = November
    M = December




    DATE CODE EXCEPTIONS


    DELCO - Freedom, Voyager, and some Sears brands:
    The code dates are stamped on the cover, usually near the posts. The first character represents the year (0-9) and the second shows the month (A-M, skipping I). For example, 4CN1 would stand for 1994, March.
    EXIDE - Napa Legend, Edge, Power-Tron and Titan: The fourth or fifth character may be a letter code for the month and the following character a number code for the year (i.e. RO8F3B stands for June 1993).




    BATTERY CAPACITY RATINGS
    Several battery capacity ratings have been established by the Battery Council International (BCl) that determine the current capacity of a battery. The current capacity is an indication of the battery's ability to develop and deliver high amperage current to the starter and provide reserve power to the electrical system.

    1) COLD CRANKING AMPS
    The first battery rating is the cold cranking amps (CCA) rating. This rating indicates the ability of a battery to deliver a specified current at low temperature. The rating is determined by the amount of current a fully charged battery can supply for 30 seconds at 0'F (- 17.8'C) without having the battery terminal voltage fall below 7.2 V.

    2) CRANKING AMPS
    The second battery rating is the cranking amps (CA) rating (not to be confused with COLD Cranking Amps), which is the battery's ability to deliver a cranking current at 32' F. This CA Rating is the same test as in the CCA rating, except it is calculated at a high temperature. A battery with a CA rating of 800 may confuse a technician who may assume it is a CCA rating number. To convert CA at 32 'F to CCA at 0 'F, divide CA by 1.25. Example: a 650 CCA rated battery has the same current capacity as a 812 CA rated battery. This apparent marketing ploy may confuse the public into thinking they are purchasing a battery which is higher in capacity than it really is.

    3) RESERVE CAPACITY
    The third battery rating, the reserve capacity rating, is the time in minutes a vehicle can be driven after the charging system fails. This is roughly equivalent to the conditions after the alternator fails while the vehicle is being driven at night with the headlights on. The battery alone must supply current to the headlights and the computer/ignition system. The assumed battery load is a constant discharge current of 25 A. The reserve capacity rating is the length of time a fully charged battery that is at a temperature of 80'F (26.7'C) can supply 25 A before the terminal voltage falls below 10.5 V.

    4) AMPERE HOUR
    The fourth battery rating, the ampere-hour rating (expressed in ampere-hours, or Ah) is the amount of current a fully charged battery can supply for 20 hours without having the terminal voltage fall below 10.5 V. This test is made at a temperature of 80'F (26.7'C). If a battery can deliver 4 A under these conditions, it is an 80-Ah battery (4 A X 20 hours = 80 Ah).




    BATTERY GROUP SIZE
    The Battery Council International (BCI) also determines the size group number. The BCI size group number identifies a battery in terms of its width, length, height, terminal design, and other physical features. Automotive manufacturers provide a designated amount of space in the engine compartment to accommodate the battery. Battery companies build batteries of various current-capacity ratings in a variety of sizes and shapes. A replacement guide is used when replacing a battery because the battery must fit into the space provided.




    BATTERY INFORMATION LABEL
    The capacity rating and group size information is usually located on the manufactures label. Additional information may also be provided.





    36 VOLT BATTERIES
    Soon you will find 36 volt batteries on new model vehicles. With the growing number of electrical devices on vehicles, the number of wires keeps growing. The advantage of 36 volt batteries will be the high voltage allows devices to operate with lower current flow, resulting in smaller wires, lightening the vehicle weight. What kind of charging system will the 36 volt battery need? A 42 volt charging system to begin with. The higher voltage output of the alternator will result in lower current from the alternator, resulting in smaller or equivalent size alternators used today. Look for these being first on the market from Mercedes or other high end cars.





    انتهى الموضوع بامر الله .

    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  9. [39]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
    المشاركات: 718
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    الموضوع السابع :
    خدمة البطارية او صيانة البطارية .

    Battery Service
    _-_-_-_-_-_-_-_-_-_-_-_-_-

    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  10. [40]
    mohamed abouzahra
    mohamed abouzahra غير متواجد حالياً
    عضو متميز
    الصورة الرمزية mohamed abouzahra


    تاريخ التسجيل: Nov 2006
    المشاركات: 718
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    Given: 0
    BATTERY SERVICE
    Battery services are routinely performed. These services include:


    1. Testing 2. Charging3. Cleaning4. Jumping a dead battery5. Adding water

    0 Not allowed!


    ان الله فى عون العبد ما دام العبد فى عون اخيه
    كل ما هو جديد فقط

  
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