Audi A4, S4

since 2000 release

Repair and operation of the car

Audi A4, S4
+ Introduction
+ Governing bodies and methods of safe operation
+ Current leaving and service
+ Engine
+ Cooling systems, heating and air conditioner
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
- Systems of electric equipment of the engine
   + System of ignition and engine management
   + System of preheat of the diesel engine
   + Diagnostics of systems of electronic control and diagnostic equipment
   - Systems of charging and start
      General information
      The battery - the main data and acquisition of the new battery
      Check and charging of the battery
      Replacement of the battery
      Storage of the battery
      System of charging - general information and security measures
      Check of system of charging
      Removal and installation of the generator
      Removal and installation of the regulator tension/replacement of brushes
      System of start of the engine - the general information and precautionary measures
      Removal and installation of a starter
      Check of system of start of the engine
+ Manual box of gear shifting
+ Automatic transmission
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

Check and charging of the battery

The low-served battery

If annual run of the car is small, for check of a zaryazhennost of the accumulator each three months should be measured electrolyte density. Measure density by the areometer and compare the received result with provided in the table given below.

Air temperature

it is above 25 °C
it is below 25 °C

Completely charged battery

1.210 — 1.230

1.270 — 1.290

It is loaded for 70%

1.170 — 1.190

1.230 — 1.250

It is completely discharged

1.050 — 1.070

1.110 — 1.130

Keep in mind that data are provided for electrolyte temperature 15 °C. At increase in temperature by each 10 °C it is necessary to add on 0.007, at similar reduction — to read on 0.007.

If the condition of the battery causes fears, check electrolyte density in each can. The difference on more than 0.040 indicates loss of electrolyte or damage of plates.

If the difference in density exceeds 0.040 accumulator is subject to replacement. If the difference in density satisfactory, but the battery is discharged, it is necessary to load and check it electrolyte density. The sequence of actions at charging is given below.

Unattended battery

If on the car the tight battery is installed, to check density of electrolyte and it is impossible to restore its level. The condition of the battery can be checked by means of the built-in indicator or the external voltmeter.

Some models are equipped with unattended batteries which case the zaryazhennost degree indicator is built in. It is located from above and changes the color at change of degree of a zaryazhennost of the battery. If the indicator has green color, the battery is completely charged if the indicator red - the battery has to be charged. The sequence of actions at charging of the battery is given below in this Section. Batteries of other producers too can have the built-in indicator of degree of a zaryazhennost. In this case follow the instructions provided in the maintenance instruction of the battery.

Batteries of all types

When checking the battery by means of the external voltmeter connect it to plugs and compare the received result to the data provided in Specifications. The result of measurements will be true if the battery was not charged at least within the last 6 hours. If it was loaded - include for 30 seconds of a headlight, then wait 5 minutes and check tension on plugs. All other electric equipment (including even intra saloon lighting) thus has to be included.

If result of measurements less than 12.0 In, the battery is discharged, and tension from 12.0 to 12.4 signals about a partial razryazhennost.

If the battery needs to be charged, remove it from the car (address to the Section Replacement of the Battery) and load, following the procedure described below.

Check of fastening of plugs of the battery and holder

If the battery is badly fixed or plugs are not fixed, premature failure of the battery because of vibration, ignition of cables or malfunction in work of electric equipment can turn out to be consequence. As at a detachment of the battery the memories given electronic blocks are erased, for example, the radio receiver, study remarks on removal and installation of the battery, address to the Section Replacement of the Battery.

Move battery plugs in different directions and check reliability of their fastening, if necessary tighten.

If the battery is badly fixed, tighten a fastening bolt the moment 20nm.

Check of the battery under loading

Attach the voltmeter to battery plugs.

Start the engine and check tension.

At the time of start of the engine at completely charged battery tension should not fall lower than 10 V (at a temperature of electrolyte about +20 °C).

If tension sharply falls and density of electrolyte in various sections is various, the battery is damaged and it needs to be replaced.


The sequence of actions given below can differ from recommended by the producer of the accumulator installed on the car. In this case use recommendations of the producer.

The ordinary and low-served battery

It is necessary to charge the battery with the current equal to 10% of capacity (for example if the capacity of the battery makes 45 Ach, it is necessary to load it with current 4.5 Ampere) until within 4 hours electrolyte density in banks does not increase.

On the other hand, the automatic charger with current about 1.5 amperes can be left included on all night long.

Chargers of the "accelerated" type which, allegedly, can charge completely the accumulator in a couple of hours, are not recommended to be used as at big currents of a plate of the battery can overheat and collapse.

At charging of the battery watch that temperature of electrolyte did not exceed 37.8 °C.

Charging of the unattended battery

Full charging of the battery of this type will require bigger time, than for charging low-served or usual. Duration of charging depends on degree of a razryazhennost and can take up to three days.

Tension developed by the charger has to lie in the range of 13.9 - 14.9 Volts, current should not exceed 25 Amperes. Under existing conditions the battery can be used in 3 hours, tension on plugs has to be about 12.5 Volts. Achievement of full charging will take longer time.

Remarks on security measures

Before charging of the battery study remarks on the security measures given in the Section Check of a Condition of the Battery, care of it and charging.

  • Do not switch-off the battery at the working engine.
  • Never close the battery nakorotko, i.e. do not connect positive (+) and negative plugs (-). Thus the battery is warmed and can burst.
  • Do not use an open flame near the battery. Electrolyte is poisonous. Do not allow its hit in eyes, on skin and on clothes. Otherwise plentifully wash out electrolyte water.
  • At the battery with the central gas outlet, at charging (crosswise vents) do not turn out a stopper.
  • Before charging of the frozen battery let's it be defrozen. The charged battery freezes at a temperature about 65 °C, the semi-charged battery at a temperature about 30 °C and discharged at a temperature about 12 °C. After defrosting check the battery for existence of cracks. If necessary replace.
  • At a battery charge the normal charger or the device with the accelerated charging remove the battery. At least, disconnect the negative (-) and a positive cable (+).
  • At use of the portable charger (small current) charging can be carried out without removal of the battery. The cable to an onboard network is not required to be disconnected thus. It is necessary, naturally, to consider data of the manufacturer of the battery.

Charging of strongly discharged and sulfatirovanny battery

The battery, long time which was not used (for example, at the long parking of the car), is discharged and sulfatirutsya over time.

If tension of idling of the battery lies lower than 11.6 In, the battery is considered strongly discharged. Check rest tension, thus address to the Section Check of a Condition of the Battery, care of it and charging.

At strongly discharged battery electrolyte consists almost of one water.

At a negative temperature such battery can freeze, and the case of the battery to burst.

Strongly discharged battery sulfatirutsya, i.e. on a surface of electrodes large slightly soluble crystals of sulphurous lead are formed. Electrolyte thus loses transparency and gets weak white coloring.

Strongly discharged and sulfatirovanny battery has to be charged with small current (about 5% of capacity size). For example, at the capacity of the battery 60 of Ach, force of charging current has to make 3 A.

Tension at charging has to make no more than 14.4 Century.

By no means it is impossible to charge strongly discharged battery with the device for fast charging.

Fast charging / help at start

Charge with the device for fast charging the battery only for ensuring start of the car. Thus force of charging current makes 20% and more from battery capacity. Thus the battery is damaged since is affected by big currents. Time not used and strongly discharged battery is long it is not necessary to load with the device for fast charging since it leads to sulphation.