Automotive Electrical and Electronics Servicing Automotive Batteries PDF

Automotive Electrical and Electronics Level-I Servicing Automotive Batteries  This module covers the units: Preparing to inspect battery  Conducting battery test  Servicing Automotive batteries  Removing and replacing batteries Preparing battery for delivery to custo...

Automotive Electrical and Electronics Level-I Servicing Automotive Batteries  This module covers the units: Preparing to inspect battery  Conducting battery test  Servicing Automotive batteries  Removing and replacing batteries Preparing battery for delivery to customer and/or storage  Unit One Preparing Battery for Inspection  This unit is developed to provide you the necessary information regarding the following content coverage and topics:  Purpose and types of Automotive batteries  Operating principles of automotive batteries  Construction of Automotive batteries  Battery Rating and Identification Codes  OHS requirements Automotive Batteries The battery is the heart of the electrical system of an automobile. An automotive battery is an electrochemical secondary cell capable of producing electric energy. The automotive battery produces direct current electricity that flows in only one direction. The batteries used in automotive applications are lead-acid battery. The lead-acid is most commonly used for automotive service because it has been found to be the most practical and economical type. This battery can be charged and discharged continuously throughout its life.  Con…. Purpose of Automotive batteries A storage battery is an electrochemical device that converts chemical energy into electric energy. It does not store electricity. The energy stored is chemical energy, which is transformed into electric energy when a circuit is completed across the terminals of the battery. There are two types of batteries used to produce electric energy: Dry cells or Primary cells and Wet cells or Secondary cells.  Con…. Operating principles of automotive batteries Electrons are moved because of the chemical reaction between the electrolyte and the two kinds of plates. The electrolyte allows electrons to move away from one kind of plate and build up on another. As a result, one kind of plate will have more than the normal number of electrons. The other plate with fewer electrons. In the plate with fewer electrons, the positive protons will predominate giving that plate a positive charge. The plate with more electrons will have a negative charge. Con….  Con…. Construction of Automotive batteries All Automotive storage batteries are similar in construction and operation but their difference lies in the number of cells, the arrangement of the cells, the number of plates in each cell, the size and thickness of the plates and the type of separators used. Automotive batteries consist of: 1. Ce lls 5. Ele m e nt 6. Ve nt plug & Ve nt h ole 2. Gr id & Plat e s 6. Ele c t r olyt e 7. T e r m inal pos t s 3. Plat e g r oups 8. Cas e (or ) Cont aine r 4. S e par at or 9. Ce ll c ove r Con….  Con…. All Automotive storage batteries are similar in construction and operation but their difference lies in:  The number of cells,  The arrangement of the cells,  the number of plates in each cell,  the size and thickness of the plates and  The type of separated used. A lead-acid battery consists of grids, positive plates, negative plates, separators, elements, electrolyte, a container, cell covers, vent plugs, and cell containers  Con…. 1. Case: Container which holds and protects all battery components and electrolyte separates cells. Translucent plastic cases allow checking electrolyte level without removing vent caps. 2. Cover: Permanently sealed to the top of the case; provides outlets for terminal posts, vent holes for venting of gases and for battery maintenance (checking electrolyte, adding water) 3. Plates: Positive and negative plates have a grid framework of antimony and lead alloy. Active material is pasted to the grid brown-colour lead dioxide (Pb02) on positive plates, gray-colour sponge lead (Pb) on negative plates. 4. Separators: Thin, porous insulators (woven glass or plastic envelopes) are placed between positive and negative plates.  Con…. 5. Cells: An assembly of connected positive and negative plates with separators in between is called a cell or element. When immersed in electrolyte, a cell produces about 2.1 volts. Battery cells are connected in series, so the number of cells determines the battery voltage. A "1 2 - volt" battery has six cells. 6. Cell Connectors: Heavy, cast alloy metal straps are welded to the negative terminal of one cell and the positive terminal of the adjoining cell until all six cells are connected in series. 7. Cell Partitions: Part of the case, the partitions separate each cell. 8. Terminal Posts: Positive and negative posts (terminals) on the case top have thick, heavy cables connected to them.  Con…. 9. Vent Caps: Types include individual filler plugs, strip-type, or box-type. They allow controlled release of hydrogen gas during charging (vehicle operation). 10. Electrolyte: A mixture of sulphuric acid (H2SO4) and water (H2O). It reacts chemically with the active materials in the plates to create an electrical pressure (voltage). It is the term used to describe the acid solution in a battery. The electrolyte used in automotive batteries is a solution (liquid combination) of 36% sulfuric acid and 64% water. This electrolyte is used for both lead- antimony and lead-calcium (maintenance-free) batteries. The chemical symbol for this sulfuric acid solution is H2SO4. It is normal for some water (H2O) in the form of hydrogen and oxygen gases to escape during charging as a result of the chemical reactions. Only pure distilled water should be added to a battery. If distilled water is not available, clean drinking water can be used. Con…. Con….  Con…. S tate of S pe c ifi c gr avity c har ge I n c old c limate I n te mpe r ate c lim ate I n tr opic al c limate Fully c har ge d 1.2 8 0 1.2 6 0 1.2 2 5 7 5 % c har ge d 1.2 6 0 1.2 15 1.18 0 5 0 % c har ge d 1.2 2 0 1.17 0 1.13 5 2 5 % c har ge d 1.19 0 1.12 0 1.0 9 0 Dis c har ge d 1.110 1.0 7 0 1.0 4 5 Con…. Electrochemical Action Chemical Reaction Lead Sulphuric Spongy Lead Water Lead Peroxide Acid Lead Sulphate Sulphate PbO2 + 2H2SO4 + Pb  PbSO4 + 2H2O + PbSO4 Positive Negative Positive Negative Plate Electrolyte Plate Plate Electrolyte Plate  Battery Identification codes Batteries that are made in different countries have identification codes. To suit an example, batteries that are made in Japan are given a battery identification code according to the Japan Industrial Standard (JIS). The battery code indicates the battery capacity, dimensions and the positions of the positive terminal whether it is right or left. Battery Battery capacity Battery Con…. Battery capacity Battery Battery capacity ID code (5 hour rate) ID code (5hour rate) ID code (5 hour rate) 28B17R/L 25 50D20R/L 40 95D31R/L 64 34B17R/L 27 55D23R/L 48 95E41R/L 80 28B19R/L 24 65D23R/L 52 105E41R/L 83 34B19R/L 27 48D26R/L 40 115E41R/L 88 36B20R/L 28 65D26R/L 52 130E41R/L 92 36B20R/L 28 75D26R/L 52 115 F 51 96 46B24R/L 36 80D26R/L 55 150 F 51 108 50B24R/L 36 65D31R/L 56 145 F 51 112 55B24R/L 36 75D31R/L 60 170 F 51 120  Con…. The performance of the battery indicates the battery capacity indirectly. Battery width and length: In the battery width and length combination is indicated by one of the eight letters ‘’A’’ through ‘’H ‘’ as follows.  Con…. Code Width (mm) Height (mm) A 162 127 B 203 127 (or) 129 C 207 135 D 204 173 E 213 176 F 213 182 G 213 222 H 220 278 Battery length: The length of the battery is indicated roughly in centimeter (cm) for instance ‘’23’’ in a battery indicates that the battery is 23 cm long.  Con…. o Position of the positive terminal. The position of the positive terminal is indicated either by ‘R’ (right side) or ‘L’ (left side). Con….  OHS requirements Safety must be a prime consideration when anyone is working around and with batteries. The hydrogen gas that batteries make when charging is very explosive. Batteries have been known to explode and drench people in sulfuric acid. When doing electrical work on vehicles it is best to disconnect the ground cable. Just remember you are messing with corrosive acid, explosive gases and 100's amps of electrical current.  Con…. Battery Hazards There are four main hazards associated with batteries: A. Battery acid: The electrolyte in a battery is corrosive and can burn skin or eyes, eat holes in clothing, or even etch a concrete floor. B. Flammable gases: Batteries emit hydrogen gas, which is flammable. It ignites easily and can cause a fire or explosion if allowed to accumulate in a small area. C. Electrical shock: Many of us are aware of this danger because we may have seen sparks fly when jumper cables are attached to a car battery. D. Weight: Batteries, like those used in forklifts, are heavy and require proper material handling equipment to lift them safely.  Con…. Personal protective equipment (PPE) To protect themselves when working with batteries, workers need to use the proper personal protective equipment (PPE). a. Goggles: Eyes need protection from electrolyte splashes. b. Face shield: Skin needs acid protection as well. c. Rubber gloves: They provide both acid protection and electrical resistance to prevent shocks. d. Rubber apron: Workers‘ clothes and bodies need the same protection.  Unit Two: Conducting battery test Battery Visual Inspection Battery service should begin with a thorough visual inspection. This inspection may reveal simple, easily corrected problems. Check for cracks in the battery case and broken terminals. Either may allow electrolyte leakage, which requires battery replacement. Check for cracked or broken cables or connections. Replace, as needed Check for corrosion on terminals and dirt or acid on the case top. Clean the terminals and case top with a mixture of water and baking soda. A battery wire brush tool is needed for heavy corrosion on the terminals.  Con…. Check for a loose battery hold-down or loose cable connections. Clean and tighten, as needed. Check the electrolyte fluid level. The level can be viewed through the translucent plastic case or by removing the vent caps and looking directly into each cell. The proper level is 1/2" above the separators (about 1/8" below the fill ring shown below). Add distilled water if necessary. Do not overfill. Check for cloudy or discolored electrolyte caused by overcharging or vibration. This could cause high self-discharge. Correct the cause and replace the battery.  Con…. Inspection of electrolyte level The electrolyte level should be checked regularly about every four weeks. It has to be 10 mm above the upper edge of the plates or between the upper and lower lines indicated on the battery case.  Con…. Inspection of battery case for cracks Check the battery case for cracks or electrolyte leakage. If the electrolyte is leaking from the battery case, the battery carrier or the parts near the battery will be corroded.  Con…. Inspection of battery vent plugs for damage Check the battery vent plugs for damage or clogged bent holes. If the vent holes in the battery vent plugs are clogged, gas generated during charging of the battery will cause the pressure inside the battery to rise and could cause damage to the battery case.  Methods of battery testing Battery tests are made to determine the state of charge and battery capacity. Testing determines if the battery:  Is in good condition.  Needs recharging.  Is defective and should be discharged. Batteries are tested in two ways: for state of charge and for performance. The state of charge of a vent- cap battery is determined with the hydrometer. The built in hydrometer or charge indicator is maintenance- free battery provides this information. An open circuit voltage test can be used. The battery- load test indicates if the battery is capable of performing its job. Battery state of charge is tested with a hydrometer or voltmeter and battery capacity is determined by a high rate discharge test. The following are some of the methods of battery testing:  Con…. A specific gravity test measures the density of a battery's sulfuric acid electrolyte to determine its state of charge and health. The test is performed using a hydrometer or a digital density meter: Hydrometer A float inside the hydrometer's bulb measures the specific gravity of the battery acid. Here are some steps for using a hydrometer to test a battery's specific gravity:  Put on eye protection and rubber gloves.  Disconnect the battery, especially if it's charging or discharging quickly.  Remove the vent cap.  Fill and drain the hydrometer 2–4 times.  Carefully insert the hydrometer into the battery cell, avoiding pushing down on the plates.  Draw some of the battery acid into the hydrometer.  Read the value indicated by the float.  Return the electrolyte to the cell.  Repeat for each cell in the battery.  Correct the reading for temperature if necessary.  Con…. Specific gravity State of charge In cold climate In temperate climate In tropical climate Fully charged 1.280 1.260 1.225 75% charged 1.260 1.215 1.180 50% charged 1.220 1.170 1.135 25% charged 1.190 1.120 1.090 Battery Voltage Test The battery voltage test is done by measuring total battery voltage with an accurate voltmeter or a special battery tester. This test determines the general state of charge and battery condition quickly. The battery voltage test is used on maintenance free batteries because test batteries do not have caps that can be removed for testing with a hydrometer. A well charged battery should have over 12 volts. If the meter reads approximately 11.5 volts, the battery is not charged adequately, or it may be defective. High Discharge test or Load test A battery load test, also termed a battery capacity test, is the best method to check battery condition. The battery load test measures the current output and performance of the battery under full current load. It is one of the most common and informative battery tests used today. A parasitic load test and a battery drain test are both ways to check for a parasitic battery drain, which is when a car's battery drains while the car is off: Parasitic load test Uses a multimeter to check for a current draw after disconnecting the negative battery cable Battery drain test Involves draining a battery at a constant current to measure its capacity and discharge curve Here are some steps you can take to perform a parasitic load test:  Prepare the vehicle: Turn off the engine, electronics, and close any doors, glove box, or trunk  Charge the battery: Use a battery charging pack or another vehicle to charge the battery  Set up the multimeter: Set the multimeter to DC voltage amps, and place the red lead in the amps port and the black lead in the COM port  Con….  Disconnect the negative battery cable: Remove the negative battery cable from the car  Connect the multimeter: Place one lead of the multimeter on the negative battery cable and the other lead on the negative battery terminal  Check the current draw: If the current draw is above the manufacturer's recommended specification, there may be a parasitic draw  Locate the source of the draw: Open the fuse box and read the schematic to determine which component is causing the draw Leakage test or Surface charge test A battery leakage test will determine if current is discharging across the top of the battery. A dirty battery can discharge when not in use. This condition shortens battery life and causes starting problems. This condition shortens battery life and causes starting problems. Battery terminal test The battery terminal test quickly checks for poor electrical connection between the terminals and the battery cables. A voltmeter is used to measure voltage drop across terminals and cables. If the voltmeter reading is 0.5 volts or above, there is high resistance at the battery cable connection. This indicates that the battery connections need to be cleaned. A good, clean battery will have less than a 0.5 volt drop. Cell voltage test The cell voltage test will let you know if the battery is discharged or defective like a hydrometer cell test, if the voltage reading on one or more cell is 2 volts or more lower than the other cells, the battery must be replaced. To perform a cell voltage test use a low voltage reading voltmeter with special cadmium (acid resistant metal) tips. Insert the tips into each cell, starting at one end of the battery and work your way to the other. Test each cell carefully. If the cells are low, but equal, recharging usually will restore the battery. If cell voltage readings vary more than 2 volts, the battery is BAD figure Cell voltage test. Peak load test During peak load test, the battery should be in a good state of charge to three fourth (3/4) or better charged, preferably fully charged. This is because a rundown battery does not accurately reflect its condition. The test should be done within 5 to 10 seconds. This load placed on the battery during this test is approximately the same as that of the starter motor.  Unit Three Servicing Batteries  Cautions about battery cleaning If water is used in the cleaning process then it should be removed from the battery tray as it will corrode it, eventually leading to the tray needing to be replaced and an expensive rebuild. It is common practice in some parts of the world to put holes in the tray to enable the water to drain out; however this practice is banned in many regions as the run off will often pose a danger to operators or damage equipment.  Procedure of preparing electrolyte Electrolyte is prepared by adding concentrated sulphuric acid to water. Electrolyte is both conductive and reactive. The purpose of the distilled water is to give freedom for the ions to move free. The electrolyte reacts chemically to combine with the active materials on the plates to form new compound and release electrons at the same time.  Types of Battery Charging Under normal conditions a hydrometer reading below 1.265 specific gravity at 80 °F, is a warning signal that the battery needs charging or is defective. When testing shows that a battery requires charging, a battery charger is required to re-energize it. The battery charger will restore the charge on the plates by forcing current back into the battery. Preparing batteries for charging  Clean and wash dirt from the battery terminals.  Inspect the case, cell covers, sealing compounds and vent plugs and make repairs if damaged.  Check the electrolyte level and fill it if necessary Safety Precautions  Do not overfill as it may bubble out of the vent openings during charging.  Because the battery emits explosive hydrogen gas, be sure not to allow fire or sparks near the battery.  Never disconnect the battery charger's cables from the battery terminals when the battery is being charged. Turn the main switch of the charger off before disconnecting them.  The battery electrolyte temperature must not exceed 45ºC (113ºF). If it goes above this, reduce the charging amperage or stop charging.  It the electrolyte accidentally gets in to the eyes, wash it out with cold water and seek medical aid. Slow Charger In this method, battery is removed from the vehicle and connected to a slow charger to recharge it. Slow chargers are usually constant current machines which use a rectifier to convert AC to DC and a rheostat to adjust current flow to the battery. Slow battery chargers operate at low rate and take considerably longer time to charge a battery. Slow charging permits the battery to be completely charged. This method does not require battery to be removed from the vehicle, as most fast chargers are portable. Its purpose is to recharge the battery sufficiently to allow the starting motor to start the engine. This is done in a short period of time, usually about 30 to 45 minutes.  Jump start using another vehicle’s battery You’ll need jumper cables and another vehicle. Make sure the second vehicle is parked close enough to allow you to connect the jumper cables to the batteries in each car with plenty of slack. Most cables are about six feet long. Check your owner’s manual for your vehicle battery location and terminal placement. 1.Open both vehicle hoods and locate the batteries. 2.Remove any terminal covers and corrosion. 3.Attach the positive (red) jumper cable to the positive (red) terminal of the dead battery. Make sure both metal clamps are firmly in contact with the terminal. 4.Attach the other end of the positive (red) jumper cable to the positive (red) terminal of the assisting battery. 5.Attach the negative (black) jumper cable to the negative (black) terminal of the assisting battery.  Con…. 6. Attach the other end of the negative (black) jumper cable to an exposed metal part of the disabled vehicle's engine, away from the battery and the carburetor/fuel-injection system. 7. Start the assisting vehicle's engine. 8. Start the disabled vehicle's engine. 9. Allow both vehicles to run connected for about three minutes. 10. Leave the jump-started vehicle running and disconnect the cables in the reverse order that they were attached and close the hoods. 11. Keep the jump-started vehicle's engine running for about a half hour to allow the battery to fully charge.  Battery Connection Series battery connections Batteries are connected with the positive (+) terminal of one battery connected to the negative (- ) terminal of the other battery with the system leads connected to the available positive (+) and negative (-) terminals. S e r ie s C o nne c t io n  Con…. Parallel battery connections Batteries are connected from terminals to the same terminals of the other batteries. The positive (+) terminal of one battery is connected with positive (+) terminal of the other battery, the negative (-) terminal of one battery is connected with negative (-) terminal of the other battery with the system cables connected to their respective negative (-) terminal or positive (+) terminal. Pa r a lle l Co nne c t io n SERIES AND PARALLEL CONNECTION You can also increase both the voltage and the capacity by connecting at least four batteries both serially and in parallel. This gives you a higher voltage battery bank that also has a longer run time for your application. This is a common practice for applications such as electric vehicles and large UPS systems. There are different ways to connect the batteries to achieve the increased voltage and capacity. With four batteries, you can create two series that are connected via a parallel connection, or two parallel banks connected by one serial connection. Either way results in the same voltage and capacity gains. You cannot wire the same batteries in series and parallel because it would short the system, but you can wire sets of batteries in series and parallel to create a larger battery bank at a higher voltage. Con…. Boost Charging The fast charger can also be used to give a battery an emergency boost when a customer is in a hurry or in some other emergency requiring quick service. The battery is charged at the normal fast charging rate for one-third to one-half the normal charging time. This puts back sufficient current for starting the engine. The vehicle should be operated for a long enough time so the car's generator or alternator can complete recharging the battery. Over Charging Batteries that are completely charged need not be charged furthermore. Because the current that is applied to charge the battery makes electrolysis of water and the water will be broken into oxygen (O) and hydrogen (H2) gasses. Oxygen find no Pb and hydrogen find no SO4 to combine with and they bubble out of the electrolyte through vent holes (battery gassing). Since oxygen and hydrogen are constituent parts of water, water is rapidly lost from the battery cells.  Unit Four Removing and replacing battery  Removing automotive batteries from the vehicle To remove a car battery, you can follow these steps: Turn off the car: Make sure the engine is off and the keys are removed from the ignition. Find the battery: Most batteries are under the hood, but some may be in the trunk or under the rear seat. Disconnect the negative terminal: This is usually marked with a minus sign and a black cable. Use a wrench to loosen the nut and then carefully remove the cable. Disconnect the positive terminal: This is usually marked with a plus sign and a red cable. Use a wrench to loosen the nut and then carefully remove the cable. Remove the battery hold-down: This may be a series of screws or a clamp across the top of the battery. Lift out the battery: Car batteries can be heavy, so use both hands and lift with your legs  Con…. Here are some safety tips to keep in mind:  Wear eye protection and insulated work gloves.  Don't let the wrench touch both terminals at the same time.  Keep the negative cable out of the way.  Even if the car is off, the battery may still have enough residual electricity to cause a spark.  Replacing automotive batteries To replace a car battery, you can follow these steps: Locate the battery: The battery is usually in the engine compartment. Ensure the engine is cool: Make sure the engine is cool enough to work safely in the area. Identify the terminals: Locate the battery terminals, which connect to the positive and negative posts. Disconnect the negative terminal: This eliminates the ground connection from the battery to the car body. Disconnect the positive terminal Remove the battery hold-down bracket: Most cars have a bar or restraint to hold the battery in place. Lift out the battery: Pull the battery out from under the hood. Clean the battery tray Insert the new battery Recycle the old battery: Dispose of the old battery safely to get rid of the toxic lead and acid.  Unit Five Preparing Battery for delivery to customer and/or storage  Conducting final inspection The purpose of inspection is to identify whether work tool/equipment and working area can be operated, adjusted and maintained safely. Not all work area, tools/equipment needs formal inspection to ensure safety and in many cases a quick visual check before use will be sufficient. However inspection is necessary for any work area, tools/ equipment where significant risks to health and safety may arise from incorrect installation, reinstallation, maintenance deterioration or any other circumstances. The need for inspection and inspection frequencies should be determined through risk assessment. Monitoring quality during servicing helps to make sure that the completed job is of the desired quality.  Con…. Importance of inspection Inspections are important as they allow you to: → listen to the concerns of workers and supervisors → gain further understanding of jobs and tasks → identify existing and potential hazards → determine underlying causes of hazards → monitor hazard controls (personal protective equipment, engineering controls, policies, procedures) → Recommend corrective action.  Completing Job card and delivery methods Completing Job card A job card is a detailed description of the work completed for a job. Job cards are used in many industries, including electrical contracting, plumbing and facilities management, to provide field workers with job details and get feedback once the job is done. The job card contains all the important details about your car like your car registration number, VIN, Engine number, your address, mobile phone number, date of registration, job card number etc. The job card is meant to ensure that the technician working on the vehicle, has a detailed 'patient' file which will help ensure that every job is completed professionally and every vehicle receives the technician's full attention and application.  Job card description Con…. To be completed by the Mechanic Description of Start Time Finish Time Hours Per Job Mechanic Signature work carried out Total Hours: Hourly Rate: Total Labour Cost:  Safe Delivery Plan The general principles that suppliers, transport operators and recipients should follow are:  Send out safety information on deliveries and collections to other parties in the delivery chain  Request safety information on deliveries and collections from other parties in the delivery chain  Include information on how the vehicle was loaded if this is needed for safe unloading  Plan the best times for deliveries to arrive  Know the route; anticipate problems  Plan to have the right number of people and equipment ready to handle the delivery when it arrives  Plan how to keep the driver and all others who may be affected by the activity safe  Implement a procedure for situations where load has shifted or collapsed in transit, so that it can be safely unloaded.