BMW 3 Series E46

since 1998 release

Repair and operation of the car

BMW 3 Series E46
+ BMW 3 cars (E46)
+ Current leaving and service
+ Engine
+ Cooling systems, heating
+ Power supply systems, injection and release
- Engine electric equipment
   General information and security measures
   + System of electronic control by ignition and injection of the petrol engine
   + System of ignition
   + System of preheat of the diesel engine
   - Systems of a charge and start
      General information on system
      The battery - the main data and leaving
      Removal and installation of the rechargeable battery
      Check of the rechargeable battery
      Generator. General information and security measures
      Removal and installation of the generator
      Check and replacement of brushes of the generator / regulator of tension
      Removal and installation, check of a starter
      Removal, installation and check of the traction relay of a starter
+ RKPP and transmission line
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment

Check of the rechargeable battery

Built-in index of degree of state of charge of the battery

The indicator has green color

The battery has sufficient degree of state of charge

The indicator has black color

Battery charging is required

The rechargeable battery of the BMW car of the 3rd series has the built-in index of degree of state of charge of the battery (the shooter on an illustration) located on the top party of the battery. This "a magic eye" can show only the main condition of state of charge, of course.

The battery does not demand service. Addition of the distilled water is not required. Level of electrolyte can be determined outside. It is in the region of the mark MAX-1-, is about 5 mm higher than lead plates.

Check of level of electrolyte (at the batteries demanding service)

If the rechargeable battery not of BMW is bought, then it is, as a rule, about the so-called low-served battery. In this case, if the level of electrolyte falls below the mark MIN, it is required to add one-two times in a year the distilled water. All sections of the battery have to have the identical level of electrolyte which is between the marks MAX and MIN.

Level of electrolyte is checked surely outside. If it cannot be made, remove carving covers and glance in section from above. Level of electrolyte has to be 5 mm above lead plates.

Check of density of electrolyte

Electrolyte density in combination with tension of the battery gives an idea of degree of state of charge of the battery.

Electrolyte temperature at measurement should not be below +10 °C.

1 Switch off ignition.

2 Turn out traffic jams from all sections of the battery. If there is a cover level, previously remove it by means of the screw-driver.

3 Ship in electrolyte денсиметр and suck away such amount of electrolyte at which the float will emerge. The specific weight (density) of the taken electrolyte sample is higher, the float emerges more. On a scale of the device it is possible to consider value of the specific weight (g/ml) or Baume's degrees (+ a °va).
4 Density of electrolyte has to be not less than 1.20 g/ml. If value of density is lower, the battery needs to be charged. Address Specifications.
5 Consistently check each section of the battery. All sections have to have the identical density (the maximum difference of 0.04 g/ml). The big difference indicates damage of the battery.
Check of tension of rest of the battery

The condition of the rechargeable battery is checked by measurement by tension voltmeter between battery poles.

6 Disconnect battery poles, address the Section Removal and installation of the rechargeable battery.
7 The battery has to be disconnected in 2 hours prior to check.

8 Attach the voltmeter to poles of the battery and measure tension.

9 Assessment of results of measurement:

12.5 In or above - the battery in satisfactory condition
12.4 In or below - the battery in an unsatisfactory state, is required charging or replacement of the battery
10 Attach a negative cable (-) to the battery, address the Section Removal and installation of the rechargeable battery.

Check of tension of the battery under loading

11 Attach the voltmeter to battery poles.
12 Ask the assistant to start the engine and consider at the same time tension.
13 In the course of start at a full charge of the battery tension should not fall lower than 10 V (at a temperature of electrolyte about +20 °C).
14 If tension at once falls and density of electrolyte in sections is various, then the battery is damaged.