Battery, Starter, Generator, Cruise Control (General Information (avant)) Audi A4 B8

1. To guarantee a long service life, the battery must be checked, serviced and maintained as described in this repair information.
2. In addition to its starting function, the battery acts as back-up and supplies power for the entire electrical system.

Note. For additional information, refer to Self Study Program No. 234; Vehicle Batteries.

CHARGING THE BATTERY USING VAS 5903

Special tools and workshop equipment required

1. Battery Charger VAS 5903 VAS 5903

Note. Battery charger -VAS 5903- charges without current and voltage peaks. Batteries can therefore also be charged when installed. When doing this, heed the safety instructions. The devices provide an assistance mode in which they provide supply for the circuits. When working on the electrical system with the electrical consumers temporarily switched on and for 1/2Guided Fault Finding1/2, the battery must be charged with a battery charger in assistance mode to prevent damage to the battery. Refer to 1/21/2 1/2g1.2.4 Battery Support Mode With VAS 5903 1/2g, page 6. For more information regarding the battery charger, refer to the Operating Instructions that came with the charger.

Procedure

1. The battery temperature must be at least +10 °C.

Switch off ignition and remove ignition key.

Turn off all electrical consumers.

Perform the battery charging prep work. Refer to Description and Operation .

Note. In vehicles without a Battery monitoring control module -J367- or Energy management control module -J644-, the battery charger clamps can be connected to the battery terminals or the positive and ground terminals in the engine compartment. In vehicles with a Battery monitoring control module -J367- or Energy management control module -J644-, the black charger clamp "-" must not be connected to the battery negative terminal but to the ground terminal in the engine compartment or the ground pin of the energy management control module -J644-.

After connecting the charging clamps, connect the battery charger electrical system connector.

Switch the charger on.

If necessary, adjust the charge current according to the battery capacity.

1. Current should be 10% of the battery capacity (with a 60 Ah battery, about 6 Ah).

When the battery is fully charged, refer to Battery charger operating instructions, disconnect the battery charger clamps "+" and "--" from the battery.

Disconnect the battery charger electrical system connector.

EXHAUSTIVELY DISCHARGED BATTERY

1. Batteries that have not been used in driving operation for a long time, for example in stored vehicles, discharge themselves.
2. Batteries are considered to be exhaustively discharged if the no-load voltage drops below 11.6 V. In the case of extended downtime under 12.2 volts, the battery is prematurely damaged.
3. Measure the no-load voltage in vehicles without a Battery monitoring control module -J367- or Energy management control module -J644-. Refer to «MEASURING NO LOAD VOLTAGE»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__measuring-no-load-voltage) .
4. Perform a battery test with a Vehicle Diagnostic Tester if the vehicle has a Battery monitoring control module -J367- or Energy management control module -J644-. Refer to «BATTERY TEST WITH VEHICLE DIAGNOSTIC TESTER»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__battery-test-with-vehicle-diagnostic-tester) .
5. With exhaustively discharged batteries, the battery acid (mixture of sulfuric acid and water) is mostly water, with a greatly reduced sulfuric acid content.
6. Exhaustively discharged batteries become sulfated, i.e. all the plate surfaces of such batteries become hardened. Instead of being transparent, the electrolyte has a slightly milky appearance.
7. The sulfating process may be reversed if an exhaustively discharged battery is recharged immediately.
8. If battery is not recharged, plates will continue to harden, and ability to accept a charge will diminish. This results in reduction of battery performance.

Procedure

1. The battery temperature must be at least +10 °C.

Discharged sulfated batteries must be charged as follows using a low charging current

Adjust the charge current to approximately 5% of the battery capacity, i.e., the charging current for a 60 Ah battery is then approximately 3 ampere.

Note. The battery voltage must be at least 0.6 V! The VAS 5903 battery charger automatically detects exhaustively discharged batteries and carefully starts the charging procedure with a low charging current. The charge current is automatically adjusted to the battery charge state.

Charge the battery. Refer to CHARGING THE BATTERY USING VAS 5903 .

1. The charging voltage may be a maximum of 14.4 V.

Note. If the battery must be replaced, follow the disposal regulations, refer to POLLUTION RISK .

RAPID CHARGING THE BATTERY, VEHICLES WITHOUT BATTERY MONITORING CONTROL MODULE -J367- OR ENERGY MANAGEMENT CONTROL MODULE -J644

Procedure

1. The battery temperature must be at least +10 °C.

Note. If the battery must be replaced, follow the disposal regulations, refer to POLLUTION RISK .

BATTERY SUPPORT MODE WITH VAS 5903

Special tools and workshop equipment required

1. Battery Charger VAS 5903 VAS 5903

The battery support mode is needed, for example, when taking breaks from fault finding in the workshop or when replacing the battery.

Procedure

Note. For more information regarding the battery charger, refer to the Operating Instructions that came with the charger. In the following, the battery support mode is described as an example of VAS 5900.

Switch off ignition and remove ignition key.

Turn off all electrical consumers.

Connect the battery charger electrical system connector VAS 5900.

1. The last selected operating mode appears on the display.

Press the Start/Stop button for approximately 5 seconds.

1. The menu selection "Charging severely discharged batteries/Support mode" is activated.

Press the ↑ button or the ↓ button in order to adjust the vehicle electrical system.

Note. If no button is pressed within 5 seconds, the VAS 5900 switches back to the main menu.

Confirm selected battery voltage with Start/Stop button.

Perform the battery support mode prep work. Refer to Description and Operation .

1. The charging clips are checked for connection to correct poles.

Confirm charging clips are connected to correct poles via Start/Stop .

1. The VAS 5900 starts the assistance mode.

To end support mode, press the Start/Stop button.

Disconnect the battery charger electrical system connector.

MAINTENANCE CHARGING WITH SOLAR PANEL VAS 6102 A

Special tools and workshop equipment required

1. Solar Panel VAS 6102 A

1. The solar panel VAS 6102 A supports the vehicle electrical system and prevents the battery from self-discharging.
2. All chargeable batteries can be charged by the solar panel.
3. The solar panel is connected at the diagnostic connection inside the vehicle. A battery charger may not be connected to the diagnostic connection.

Procedure

Scheme 119

Note. For more information regarding the solar panel VAS 6102 A refer to the Owner's Manual that came with VAS 6102 A.

Secure the solar panel VAS 6102 A on the interior rearview mirror -1-.

Lay the bottom of the solar panel on the instrument panel -2-.

Note. The whole solar panel VAS 6102 A may not lie on the instrument panel. Only the bottom edge may be used for support. If it touches completely, the color of the instrument panel could change.

Pull the securing string together so that the solar panel is close to the windshield.

Connect the solar panel to the diagnostic connection -arrow-.

Scheme 120

1. The green LED in the solar panel frame displays the function: The brighter the LED, the higher the charging current. It is not possible to overcharge the battery due to the integrated electronics.

CRUISE CONTROL, VEHICLES WITH ELECTRONIC POWER CONTROL

1. The function of the Cruise Control System (CCS) is controlled by the Engine Control Module on vehicles with Electronic Power Control (EPC).
2. Malfunctions in relation to CCS are sent via the Engine Control Module (ECM).

For trouble shooting, use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

SAFETY PROCEDURES AND PRECAUTIONS

Before beginning work, the mechanics must be acquainted with the possible risks when handling batteries.

LEAD-ACID BATTERY WARNINGS AND SAFETY PRECAUTIONS

Recognizing and Preventing Risks

It is dangerous to handle batteries. These risks can be avoided by following the warnings on the battery, in the operating instructions, and in the repair information.

Explanation Of Battery Symbols

Scheme 121

1. When working in the area of the battery, fire, sparks, open light and smoking are prohibited. Avoid sparks from cables, electrical devices and electrostatic discharge. Do not place any tools on the battery to avoid short circuits.
2. Eye protection must be worn when working on the battery.
3. Keep electrolyte and batteries out of the reach of children.
4. Disposal: Old batteries require special disposal. They must only be disposed of in accordance with the legal requirements at an authorized site.
5. Do not dispose of old batteries in household waste.
6. When handling batteries, there is a risk of explosion. Battery charging produces a highly explosive gas mixture.
7. Follow the notes on the battery in the repair information "Electrical Equipment General Information" and in the Owner's manual.
8. Battery acid can cause severe burns! Battery acid is severely corrosive so protective gloves and eye wear must be worn when working on the battery. The battery must not be tipped, because acid may spill from the ventilation openings.

THERE IS A RISK OF INJURY FROM THE BATTERY ACID.

PROTECT AGAINST INJURY BY USING PROTECTIVE EYEWEAR AND CLOTHING.

RISK OF EXPLOSION DUE TO THE EXPLOSIVE GAS THAT FORMS DURING BATTERY CHARGING.

POLLUTION RISK

Only maintenance-free batteries conforming to standards "TL82506" (as of December 1997) and "VW75073" (as of August 2001) may be installed.

VISUAL CHECK

Before performing extensive measurements, inspect visually.

1. External battery condition
2. Battery connections
3. Secure battery seating.

ABSORBENT GLASS MAT (AGM) BATTERY, WITHOUT VISUAL INDICATOR

1. AGM batteries are deep cycle-resistant and leak-proof.
2. Lead-acid batteries, or AGM batteries, are filled with electrolyte contained in an absorbent glass mat ("A" bsorbent "G" lass "M" at = AGM). The battery is closed and equipped with breather valves.
3. These batteries cannot have a "visual indicator" due to the fixed electrolyte. AGM batteries are marked with "AGM" on the battery.

Note. AGM batteries cannot and must not be opened and distilled water must not be added. Only perform a visual inspection.

ABSORBENT GLASS MAT (AGM) BATTERY, CHECKING

Perform Battery Checks In The Following Sequence

Visual check. Refer to VISUAL CHECK .

Test the battery. Refer to BATTERY, CHECKING - VEHICLES WITHOUT Battery Monitoring Control Module -J367- OR Energy Management Control Module -J644 or CURRENT DRAW TEST .

Additional procedure depends on the result of the battery test with the battery tester.

BATTERY WITH VISUAL INDICATOR

Lead acid batteries with visual indicators are filled with fluid electrolyte (wet battery). They do not have sealing plugs for filling with distilled water.

Note. If batteries with a visual indicator are equipped with sealing plugs for production reasons, the plugs are covered with plastic sheeting. The covering must not be removed and distilled water must not be added. Only perform a visual inspection.

The visual indicator -arrow- gives information about the electrolyte level and charge condition of the battery by means of a color display. Possible color displays, refer to BATTERY WITH VISUAL INDICATOR .

Scheme 122

Reinforced battery for certain vehicles with Start/Stop

1. This battery is used for the special requirements in certain vehicles with Start/Stop. These batteries have "EFB" on the battery cover. "EFB" stands for "enhanced flooded battery" (enhanced wet battery).
2. An EFB battery may only be replaced with another EFB battery.
3. The information regarding batteries with a visual indicator also applies to EFB batteries.

Note. EFB batteries are being used in certain Audi A1 and Audi A3 models from August 2011.

BATTERY WITH VISUAL INDICATOR, CHECKING

Perform Battery Checks In The Following Sequence

Visual check. Refer to VISUAL CHECK .

Check the color of the visual indicator. Refer to ELECTROLYTE LEVEL COLOR, CHECKING .

Check the battery electrolyte level. Refer to ELECTROLYTE LEVEL, CHECKING .

Test the battery. Refer to BATTERY, CHECKING - VEHICLES WITHOUT Battery Monitoring Control Module -J367- OR Energy Management Control Module -J644 or CURRENT DRAW TEST .

Additional procedure depends on the result of the battery test with the battery tester.

BATTERY POST/TERMINAL

To prevent damage to the battery terminals and battery housing, observe the following

Scheme 123

1. Do not put any grease on the battery terminals.
2. Battery terminal clamps -arrows- must only be installed by hand without applying force.
3. Install battery terminal clamps so the terminal is flush with the clamp or protrudes out of it.
4. Battery terminal clamps and auxiliary clamps, tightening specification. Refer to «Specifications»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-avant) .
5. After tightening the battery terminal clamps to the specified torque, the threaded connections must not be tightened again.

CENTRAL VENTING SYSTEM

To prevent the gas that forms in the engine compartment or vehicle interior during battery charging from causing damage or posing a threat to health, the gas is discharged centrally through an opening on the top cover side of the battery.

Make sure the central venting hose or tube is always secured on the battery.

Make sure the central venting hose or tube is not pinched. Only then can battery be properly vented.

Note. Newer generation batteries have a fine mesh flame trap at the central venting exit point. The flame trap is a round fiberglass mat approximately 15 mm wide and 2 mm thick that works like a valve. On the one hand, it allows the gas formed during battery charging to flow out and on the other hand, prevents the explosive gas in the battery from igniting.

ELECTROLYTE LEVEL COLOR, CHECKING

Procedure

Note. Because the visual indicator is located in only one battery cell, the battery acid level is only checked for that cell.

To obtain an accurate reading, gently tap the visual indicator -arrow- with a screwdriver handle.

Note. When charging the battery and while driving, air bubbles can form below the visual indicator and result in an incorrect color display. Tapping releases the air bubbles under the visual indicator.

Check the battery acid level using the color indicator. Two different displays are possible

Note. If the battery must be replaced, follow the disposal regulations. Refer to POLLUTION RISK \\.

ELECTROLYTE LEVEL, CHECKING

Procedure

Maintaining the correct electrolyte level in the battery is an important factor affecting the length of the battery's service life.

If the "Min" and "Max" marking on the outside of the battery can be seen, simply inspect by sight.

1. The electrolyte level must be above the "Min" marking but must only go as high as the "Max" marking.

Lead acid batteries that are not maintenance-free are filled with fluid electrolyte (wet battery). They have sealing plugs.

Before performing extensive measurements, inspect visually.

1. External battery condition
2. Battery connections
3. Secure battery seating.

TESTING

Perform Battery Checks In The Following Sequence

Visual check. Refer to VISUAL CHECK .

Check the battery electrolyte level. Refer to ELECTROLYTE LEVEL, CHECKING .

Battery testing with the Battery tester VAS 6161, refer to BATTERY TEST USING BATTERY TESTER VAS 6161 or measure the battery acid density, refer to ACID DENSITY, MEASURING .

Additional procedure depends on the result of the battery test with the battery tester.

ACID DENSITY, MEASURING

Special tools and workshop equipment required

1. Refractometer T10007 or
2. Commercially Available Hydrometer

Procedure

In conjunction with the battery test using the Battery tester VAS 6161, refer to BATTERY TEST USING BATTERY TESTER VAS 6161 , the acid density test provides information about the condition of the battery.

1. The temperature of the battery acid must be at least +10° C (50° F).

Note. Specific density of the electrolyte can be checked immediately after charging battery.

Remove all sealing plugs of battery cells.

Dip hydrometer into battery cell and siphon off enough electrolyte until the float floats freely in electrolyte.

Scheme 124

1. The higher the specific weight of the siphoned battery acid, the higher the float will float.
2. The acid density of the electrolyte can be read off in kg/dm 3 on the hydrometer scale (specific density of the battery acid).

Compare hydrometer reading to values given in table.

Charge battery and repeat acid density test.

If the specified values are not reached, replace the battery.

Note. The measured values for the specific density of the individual battery cells must not deviate by more than 0.03 kg/dm 3 , otherwise the battery should be replaced.

If the specified values are reached, reinstall the sealing plugs on the battery cells.

Note. If the battery must be replaced, follow the disposal regulations. Refer to POLLUTION RISK .

To prevent damage to the battery terminals and battery housing, observe the following

1. Do not put any grease on the battery terminals.
2. Battery terminal clamps -arrows- must only be installed by hand without applying force.
3. Install battery terminal clamps so the terminal is flush with the clamp or protrudes out of it.
4. Battery terminal clamps and auxiliary clamps, tightening specification, refer to «Specifications»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-avant) .
5. After tightening the battery terminal clamps to the specified torque, the threaded connections must not be tightened again.

To prevent the gas resulting from battery charging from causing damage or putting health at risk, the gas is discharged centrally through an opening on the top cover side of the battery.

Make sure the central venting hose or tube is always secured on the battery.

Make sure the central venting hose or tube is not pinched. Only then can battery be properly vented.

Note. Newer generation batteries have a fine mesh flame trap at the central venting exit point. The flame trap is a round fiberglass mat approximately 15 mm wide and 2 mm thick that works like a valve. On the one hand, it allows the gas formed during battery charging to flow out and on the other hand, prevents the explosive gas in the battery from igniting.

Procedure

Maintaining the correct electrolyte level in the battery is an important factor affecting the length of the battery's service life.

If the "Min" and "Max" marking on the outside of the battery can be seen, simply inspect by sight.

1. The electrolyte level must be above the "Min" marking but must only go as high as the "Max" marking.

If it is difficult to see the "Min" and "Max" markings on the outside of the battery or they cannot be seen because the battery housing is opaque, remove the sealing plugs.

Check electrolyte level by visually checking the inside of the battery.

1. The electrolyte level must coincide with the internal level mark (plastic web). This corresponds to the outer "max" marking.

Screw in the sealing plugs of battery cells.

Scheme 125

1. Bolts 1 Nm
2. Cover With 3 retaining tabs
3. Bolts 2 Nm
4. Voltage Regulator Removing: -- Remove bolts -item 1- and remove protective cap -item 2-. -- Remove the bolts -item 3- and remove the voltage regulator. Carbon brush wear limit: 5 mm
5. Generator

BOSCH GENERATOR OVERVIEW, FROM 2001

Note. The generators were implemented as a running change.

Scheme 126

1. Generator
2. Voltage Regulator Removing and installing, refer to «VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__voltage-regulator-bosch-generator-from-2001) . Carbon brushes, checking, refer to «CARBON BRUSH, CHECKING, BOSCH GENERATORS FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__carbon-brush-checking-bosch-generators-from) .
3. Screw 2.5 Nm
4. Cover
5. Nut 12 Nm
6. Nut 30 Nm
7. Screw 3 Nm
8. Screw 1.5 Nm

BOSCH GENERATOR OVERVIEW, FROM 2007

Note. The new generators are installed as a running change.

Scheme 127

1. Nut 65 Nm
2. Ribbed Belt Pulley
3. Generator
4. Voltage Regulator Removing and installing, refer to «VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2007»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__voltage-regulator-bosch-generator-from-2007) . Carbon brushes, checking, refer to «CARBON BRUSH, CHECKING, BOSCH GENERATORS FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__carbon-brush-checking-bosch-generators-from) .
5. Screw 1.5 Nm
6. Cover
7. Screw 3 Nm
8. Screw 2.5 Nm

Scheme 128

1. Generator
2. Voltage Regulator Removing: -- Remove the nuts -item 5- and cover -item 4-. -- Remove the bolt -item 6- and nuts -item 7- and remove the voltage regulator. Carbon brush wear limit: 5 mm
3. Protective Cap
4. Cover
5. Nut 2 Nm
6. Screw 2 Nm
7. Nut 3.5 Nm Quantity 2

VALEO GENERATOR OVERVIEW, FROM 2001

Note. The generators were implemented as a running change.

Scheme 129

1. Generator
2. Voltage Regulator Removing and installing, refer to one of the following: Through MY 07, refer to «VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__voltage-regulator-valeo-generator-from-2001) . From MY 07, refer to «VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2007»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__voltage-regulator-valeo-generator-from-2007) . Carbon brush, checking, refer to one of the following: Through MY 07, refer to «CARBON BRUSH CHECKING, VALEO GENERATOR, FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__carbon-brush-checking-valeo-generator-from) . From MY 07, refer to «CARBON BRUSH CHECKING, VALEO GENERATOR, FROM 2007»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__carbon-brush-checking-valeo-generator-from) .
3. Screw 2 Nm
4. Cover
5. Protective Cap
6. Screw 2 Nm

FASTENER TIGHTENING SPECIFICATIONS

BATTERY TEST USING BATTERY TESTER VAS 6161

Special tools and workshop equipment required

1. Battery Tester VAS 6161

Maintenance-free batteries must not be opened. Otherwise, the warranty is voided.

1. When performing the battery test with the VAS 6161, the battery ground wire must not be disconnected.
2. When using the VAS 6161 the battery is no longer being charged. The principle of dynamic conductivity measurement is applied. As a result, numerous measurements are possible without recharging the battery.
3. The no-load voltage measurement can be performed without a waiting period.
4. All battery types are stored in the device. They can be refreshed by performing an update.
5. The battery barcode can be directly recorded via the optional 2D scanner.
6. The integrated temperature sensor increases the quality of the measurements.
7. The data can be stored on a SD memory card.

Note. Information about the VAS 6161 refer to the operating instructions.

Note. Using the VAS 6161, refer to the operating instructions.

Procedure

1. The battery temperature must be at least +10° C (50 °F).

Turn off the ignition and all electrical consumers.

On a battery with a visual indicator, check its color display. Refer to ELECTROLYTE LEVEL COLOR, CHECKING .

Switch on the VAS 6161.

Clamp the red battery tester test clamp "+" to the battery positive terminal or the jump start terminal in the engine compartment.

Clamp the black battery tester test clamp "-" to the battery ground terminal or the jump start terminal in the engine compartment.

Note. Make sure the test clamps make good contact!

Select one of the following

1. Maintenance test
2. Service test
3. Warranty test

Maintenance test

Select "Maintenance Test".

Connect the scanner and scan in the vehicle identification number.

Select the connection type: "at the battery terminal" or "at the jump start terminal".

Section vehicle model.

Scan in the battery barcode.

To determine the temperature, hold the temperature sensor approximately 5 cm above the battery or the jump start terminal until a constant temperature is shown.

Start the test.

When necessary, print out the test protocol.

Service test

Select "Service Test".

Section vehicle model.

To determine the temperature, hold the temperature sensor approximately 5 cm above the battery until a constant temperature is shown.

Select the type of battery: "Standard", "AGM", "2*6V" or "Gel".

Select the standard: "CCA", "JIS", "DIN", "SAE", "IEC" or "EN".

Start the test.

When necessary, print out the test protocol.

Warranty test

Select "Warranty Test".

Select the installation location: "inside the vehicle" or "outside the vehicle".

Section vehicle model.

To determine the temperature, hold the temperature sensor approximately 5 cm above the battery until a constant temperature is shown.

Select the type of battery: "Standard", "AGM", "2*6V" or "Gel".

Select the appropriate capacity with the arrow buttons.

Start the test.

When necessary, print out the test protocol.

Note. The printed test results are required for warranty claims.

Switch off the battery tester.

Remove the test clamps.

Test Result On The Printout

Scheme 130

1. Type of test
2. Test result
3. Measured voltage
4. Measured nominal value of the battery
5. Battery nominal value set at the tester
6. Temperature measured above the battery
7. Battery installed location
8. Location of the battery terminal set at the tester
9. Set battery type

Note. If the battery must be replaced, follow the disposal regulations. Refer to POLLUTION RISK .

MEASURING NO LOAD VOLTAGE

Special tools and workshop equipment required

1. Hand-Held Multimeter V.A.G 1526E

Maintenance-free batteries must not be opened. Otherwise, the warranty is voided.

Note. Measuring the no-load voltage, for example, during the prescribed maintenance and service work on vehicles in storage, determines whether the battery must be recharged. Refer to Maintenance, Diagnosis .

Procedure

To ensure a correct measurement, the following points must be followed.

1. Battery must not be loaded by electrical consumers within the next 2 hours before measurement.
2. After battery charging or engine operation, the measurement can be performed only after a 12 hour waiting period.
3. The battery temperature must be at least 10° C (50 °F).

After a waiting period of at least 12 hours

Measure the voltage between the battery terminal clamps.

1. Specified value: 12.5 volts or higher, the battery is OK.

If the no-load voltage is under 12.5 volts, the battery must be recharged. Refer to CHARGING THE BATTERY USING VAS 5903 .

After charging for 5 minutes, the current draw must be measured again. Refer to CURRENT DRAW TEST .

If the battery no-load voltage is 11.6 volts or lower, the battery is exhaustively discharged. Refer to EXHAUSTIVELY DISCHARGED BATTERY .

CURRENT DRAW TEST

Special tools and workshop equipment required

1. Battery Charger VAS 5903 VAS 5903

Maintenance-free batteries must not be opened. Otherwise, the warranty is voided.

By checking a battery's current draw capacity during charging, a decision can be quickly made as to whether a partially or exhaustively discharged battery, refer to EXHAUSTIVELY DISCHARGED BATTERY can be made usable again by recharging or if it must be replaced.

Note. When charging with the battery charger, VAS 5903, displays the current draw on the device. For more information regarding the battery charger, refer to the Operating Instructions that came with the charger.

Procedure

1. The battery temperature must be at least +10° C (50 °F).
2. The battery charger must be able to deliver at least 30 amps (A), as with the battery charger VAS 5903.
3. Battery charger connected and switched on.

Measure the battery charge current after 5 minutes of charging.

1. Specified value: The charge current must be higher than 10% of the nominal capacity.
2. Example: Charge current on a 60 Ah battery after 5 minutes of charging: greater than 6 A.

If the target value is reached, proceed with the charging operation until the battery is fully charged.

Then test the battery with the battery tester

1. With the Battery tester VAS 6161 without waiting period, refer to «BATTERY TEST USING BATTERY TESTER VAS 6161»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__battery-test-using-battery-tester-vas) .

If the specified value is not met, replace the battery. Refer to Removal and Installation .

Note. If the battery must be replaced, follow the disposal regulations. Refer to POLLUTION RISK .

1. In certain model series the following is responsible for monitoring the electrical system: energy management control module -J644- or battery monitoring control module -J367- in connection with the data bus on board diagnostic interface -J533- , refer to the appropriate System Wiring Diagram information. The battery test for these vehicles is performed during "Guided Fault Finding".
2. If the battery test is not possible with "Guided Fault Finding" due to a partially or exhaustively discharged battery, the battery can be quickly evaluated with the help of the "current draw test".
3. Maintenance-free batteries must not be opened. Otherwise, the warranty is voided.

BATTERY TEST WITH VEHICLE DIAGNOSTIC TESTER

Special tools and workshop equipment required

1. Vehicle Diagnostic Tester

Procedure

1. No charging unit must be connected when checking the battery, and the engine must not be running.
2. The battery temperature must be at least 10 °C (50 °F).
3. Diagnostic system temperature must be between +5 and 45 °C (41 and 113 °F).

Connect the Vehicle Diagnostic Tester. Refer to CONNECTING THE VEHICLE DIAGNOSTIC TESTER .

Note. If a malfunction message appears in the display, refer to the Vehicle Diagnostic Tester Operating Instructions.

Press the Guided Functions button in the selection.

Display for example

Scheme 131

Enter vehicle identification number by selecting -A- and the appropriate text line -1-.

Select the function or path

Follow the instructions on the Vehicle Diagnostic Tester display. The following results can be displayed

1. Battery is OK.
2. Charge battery.
3. Replace battery.

After battery check

Press the GO TO button.

Select function "Exit".

Switch ignition off and disconnect diagnostic connector.

If necessary, charge the battery. Refer to CHARGING THE BATTERY USING VAS 5903 or replace it. Refer to Removal and Installation .

Note. If the battery must be replaced, follow the disposal regulations. Refer to POLLUTION RISK .

Special tools and workshop equipment required

1. Battery Charger VAS 5903 VAS 5903

By checking a battery's current draw capacity during charging, a decision can be quickly made as to whether a partially or exhaustively discharged battery, refer to EXHAUSTIVELY DISCHARGED BATTERY can be made usable again by recharging or if it must be replaced.

Note. When charging with the battery charger, VAS 5903, displays the current draw on the device. For more information regarding the battery charger, refer to the Operating Instructions that came with the charger.

Procedure

1. The battery temperature must be at least +10° C (50° F).
2. The battery charger must be able to deliver at least 30 amps (A), as with the battery charger VAS 5903.
3. Battery charger connected and switched on.

Measure the battery charge current after 5 minutes of charging.

1. Specified value: The charge current must be higher than 10% of the nominal capacity.
2. Example: Charge current on a 60 Ah battery after 5 minutes of charging: greater than 6 A.

If the target value is reached, proceed with the charging operation until the battery is fully charged.

Then test the battery with the vehicle diagnostic tester. Refer to BATTERY TEST WITH VEHICLE DIAGNOSTIC TESTER .

If the specified value is not met, replace the battery. Refer to Removal and Installation .

Note. If the battery must be replaced, follow the disposal regulations. Refer to POLLUTION RISK .

MEASURING NO-LOAD VOLTAGE, TRANSPORT MODE NOT ACTIVE

Special tools and workshop equipment required

1. Hand-Held Multimeter V.A.G 1526E

Note. The no-load voltage measurement should only be used to evaluate the battery condition if it is not possible to perform the battery test with the Vehicle Diagnostic Tester and if the transport mode is not activated in the battery monitoring control module -J367- or energy management control module -J644-.

Procedure

Always observe the following to ensure correct measurement

1. Battery remains installed in vehicle, battery ground (GND) strap must not be disconnected.
2. Open the front lid or rear lid and lock the lid lock in the closed position so that the luggage compartment lamp is not switched on.
3. Lock vehicle with central locking system.
4. Battery must not be loaded by electrical consumers within the next 2 hours before measurement.
5. Battery must not be charged within the next 12 hours before measurement.
6. The battery temperature must be at least -10 °C (14 °F).

Perform the prep work for the no-load voltage measurement. Refer to Description and Operation .

After a waiting period of at least 2 hours

Connect the V.A.G 1526E between the battery terminal clamps or to the positive terminal "+" and ground terminal "-".

Measure the voltage between the battery terminal clamps.

1. Specified value: 12.5 volts or higher, the battery is OK.

If the no-load voltage is under 12.5 volts, the battery must be recharged. Refer to CHARGING THE BATTERY USING VAS 5903 .

After charging for 5 minutes, the current draw must be measured again. Refer to CURRENT DRAW TEST .

If the battery no-load voltage is 11.6 volts or lower, the battery is exhaustively discharged. Refer to EXHAUSTIVELY DISCHARGED BATTERY .

MEASURING NO-LOAD VOLTAGE, TRANSPORT MODE ACTIVE

Note. During the prescribed maintenance and service work on vehicles in storage, the charge state can be read in % (SOC = state of charge) in the trip odometer display when the transport mode is active. This determines whether the battery needs to be fully charged. Refer to Maintenance, Diagnosis .

Procedure

The following test is only possible if the transport mode is active in the battery monitoring control module -J367- or energy management control module -J644-. If the transport mode is activated later, for example, when storing used vehicles, the SOC can first be determined when "the bus is at rest".

Open the driver door.

Switch ignition on.

Read the SOC in % on the trip odometer display.

Note. Depending on the version, "TRA" can precede the value.

1. Specified value: 50% or higher, the battery charge level is OK.

If the battery charge level is less than 50%, the battery must be fully charged. Refer to BATTERY, CHARGING .

After charging for 5 minutes, the current draw must be measured again. Refer to CURRENT DRAW TEST .

If the battery charge level is 0%, the battery is exhaustively discharged. Refer to EXHAUSTIVELY DISCHARGED BATTERY .

CHECKING THE RIBBED BELT PULLEY WITH FREEWHEEL

Procedure

1. The ribbed belt pulley with freewheel is removed. Refer to «RIBBED BELT PULLEY WITH FREEWHEEL»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__ribbed-belt-pulley-with-freewheel) .

Hold the inner ring -1- on the ribbed belt pulley with one hand using the thumb and index finger and the outer ring -2- with the other hand using the thumb and index finger.

Scheme 132

Hold the inner ring tight and turn the outer ring in the rotation direction of the generator.

1. If the free-running hub is intact, the outer does not turn.

Hold the inner ring tight and turn the outer ring opposite the rotation direction of the generator.

1. If the free-running hub in intact, the outer ring turns with slight resistance.

Replace the ribbed belt pulley if the free-running hub does not function as described.

GENERATOR, CHECKING

Test the generator in "Guided Fault Finding" under "Body/Electrical System/26 - Starter, voltage supply/electrical components/C generator, testing", refer to the Vehicle Diagnostic Tester.

CARBON BRUSH, CHECKING, BOSCH GENERATORS FROM 2001

Procedure

Scheme 133

Remove the voltage regulator, refer to one of the following

Through MY 07, refer to VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2001 .

From MY 07, refer to VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2007 .

Check carbon brushes for length -a-.

1. Wear limit: -a- = 5 mm.

Install the voltage regulator, refer to one of the following

Through MY 07, refer to VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2001 .

From MY 07, refer to VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2007 .

CARBON BRUSH CHECKING, VALEO GENERATOR, FROM 2001

Procedure

Scheme 134

Remove voltage regulator. Refer to VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2001 .

Check carbon brushes for length -a-.

1. Wear limit: -a- = 5 mm.

Install the voltage regulator. Refer to VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2001 .

CARBON BRUSH CHECKING, VALEO GENERATOR, FROM 2007

Special tools and workshop equipment required

1. Feeler Gauge 0.3 mm

Procedure

Scheme 135

Remove voltage regulator. Refer to VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2007 .

Insert a feeler gauge 0.3 mm -3- between protective cap -2- and the carbon brushes.

Remove the protective cap from voltage regulator -1- -arrow-.

Check carbon brushes for length -a-.

1. Wear limit: -a- = 5 mm.

With protective cap -2- installed, use feeler gauge -4- to press carbon brushes -3- down.

Scheme 136

Push the protective cap off -arrow- until the bar of the protective cap presses the carbon brushes down.

Install the voltage regulator. Refer to VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2007 .

VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2001

Removal

Scheme 137

Remove the generator. Refer to Removal and Installation .

Remove bolt -1- and nuts -3- and -4-.

Remove cover -2- at rear side of generator.

Remove screws -arrows-.

Scheme 138

Remove voltage regulator.

Installation

When installing the voltage regulator, make sure the carbon brushes rest properly on the slip rings.

Install in reverse order of removal, observing the following

Install the generator. Refer to Removal and Installation .

1. Tightening specification, refer to «BOSCH GENERATOR OVERVIEW, FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__bosch-generator-overview-from-2001) .

VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2007

Removal

Scheme 139

Remove the generator. Refer to Removal and Installation .

Remove screws -arrows-.

Remove cover -1- at rear side of generator.

Remove screws -arrows-.

Scheme 140

Remove voltage regulator -1-.

Installation

When installing the voltage regulator, make sure the carbon brushes rest properly on the slip rings.

Install in reverse order of removal, observing the following

Install the generator. Refer to Removal and Installation .

1. Tightening specification, refer to «BOSCH GENERATOR OVERVIEW, FROM 2007»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__bosch-generator-overview-from-2007) .

VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2001

Removal

Scheme 141

Remove the generator. Refer to Removal and Installation .

Press out cover from threaded pins at rear side of generator -arrows-.

Remove bolts -1- and double bolt -2-.

Scheme 142

Remove voltage regulator.

Installation

Scheme 143

Press off protective cap -2- from voltage regulator -1- in -direction of arrow-.

When installing the voltage regulator, make sure the carbon brushes rest properly on the slip rings.

Attach protective cap with voltage regulator installed.

Install in reverse order of removal, observing the following

Install the generator. Refer to Removal and Installation .

1. Tightening specification, refer to «VALEO GENERATOR OVERVIEW, FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__valeo-generator-overview-from-2001) .

VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2007

Special tools and workshop equipment required

1. Feeler Gauge 0.3 mm

Removal

Remove the generator. Refer to Removal and Installation .

Press out cover from threaded pins at rear side of generator -arrows-.

Remove bolts -1- and double bolt -2-.

Remove voltage regulator.

Installation

Scheme 144

Insert a feeler gauge 0.3 mm -4- between protective cap -2- and carbon brushes -3-.

Pull the protective cap off until the bar of the protective cap presses the carbon brushes down.

After installation of the voltage regulator, press the protective cap all the way on.

Install in reverse order of removal, observing the following

Install the generator. Refer to Removal and Installation .

1. Tightening specification, refer to «VALEO GENERATOR OVERVIEW, FROM 2001»(/audi/a4/b8-2007-2012/remont/charging-system/#battery-starter-generator-cruise-control-general-information-avant__valeo-generator-overview-from-2001) .

RIBBED BELT PULLEY WITHOUT FREEWHEEL

Special tools and workshop equipment required

1. Socket 3310
2. 8 mm Hex Socket or TORX T50

Removal

Scheme 145

Remove the generator. Refer to Removal and Installation .

If present, press the protective cap off the generator pulley.

Counter-hold nut using 3310 and rotate generator shaft clockwise to loosen it.

Remove ribbed belt pulley.

Installation

Install in reverse order of removal. Note the following

Turn the generator shaft counterclockwise to tighten.

Clip protective cap onto generator pulley.

Tightening Specifications

RIBBED BELT PULLEY WITH FREEWHEEL

Special tools and workshop equipment required

1. Multi-point Adapter 3400
2. 8 mm hex socket or TORX T50

Removal

Scheme 146

Remove the generator. Refer to Removal and Installation .

If present, press the protective cap off the generator pulley.

Counter-hold pulley using 3400 and rotate generator shaft clockwise to loosen it.

Installation

Install in reverse order of removal. Note the following

Turn the generator shaft counterclockwise to tighten.

Clip protective cap onto generator pulley.

Tightening Specifications

Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

Scheme 152

Scheme 153

Scheme 154

1. Socket 3310
2. Multi-point Adapter 3400
3. 8 mm Hex Socket or TORX T50
4. Feeler Gauge 0.3 mm
5. Refractometer T10007 or
6. Commercially Available Hydrometer
7. Hand-Held Multimeter V.A.G 1526E
8. Battery Charger VAS 5903 VAS 5903
9. Solar Panel VAS 6102 A
10. Battery Tester VAS 6161

See also:
• Description and Operation
• Maintenance, Diagnosis
• CONNECTING THE VEHICLE DIAGNOSTIC TESTER
• LEAD-ACID BATTERY WARNINGS AND SAFETY PRECAUTIONS
• VISUAL CHECK
• VISUAL CHECK
• RAPID CHARGING THE BATTERY, VEHICLES WITHOUT BATTERY MONITORING CONTROL MODULE -J367- OR ENERGY MANAGEMENT CONTROL MODULE -J644
• MEASURING NO LOAD VOLTAGE
• BATTERY TEST WITH VEHICLE DIAGNOSTIC TESTER
• CHARGING THE BATTERY USING VAS 5903
• POLLUTION RISK
• THERE IS A RISK OF INJURY FROM THE BATTERY ACID.
• RISK OF EXPLOSION DUE TO THE EXPLOSIVE GAS THAT FORMS DURING BATTERY CHARGING.
• BATTERY WITH VISUAL INDICATOR
• ELECTROLYTE LEVEL COLOR, CHECKING
• ELECTROLYTE LEVEL, CHECKING
• PROTECT AGAINST INJURY BY USING PROTECTIVE EYEWEAR AND CLOTHING.
• BATTERY TEST USING BATTERY TESTER VAS 6161
• ACID DENSITY, MEASURING
• VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2001
• CARBON BRUSH, CHECKING, BOSCH GENERATORS FROM 2001
• VOLTAGE REGULATOR, BOSCH GENERATOR, FROM 2007
• VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2001
• VOLTAGE REGULATOR, VALEO GENERATOR, FROM 2007
• CARBON BRUSH CHECKING, VALEO GENERATOR, FROM 2001
• BOSCH GENERATOR OVERVIEW, FROM 2001
• BOSCH GENERATOR OVERVIEW, FROM 2007
• CURRENT DRAW TEST
• EXHAUSTIVELY DISCHARGED BATTERY
• RIBBED BELT PULLEY WITH FREEWHEEL
• VALEO GENERATOR OVERVIEW, FROM 2001