BMW 7_aya the E38 series from 1994 to 2002
1. Introduction
2. Governing bodies and methods of operation
3. Settings and routine maintenance of the car
4. Engine
5. Cooling systems of the engine, heating, ventilation and air conditioning
6. A power supply system and production of the fulfilled gases
7. Systems of electric equipment of the engine
7.1. Systems of ignition, preheat and engine management
7.2. Systems of a charge and start
7.2.1. General information
7.2.2. The rechargeable battery - the general information, recommendations about service
7.2.3. System of a charge - general information and security measures
7.2.4. Removal and installation of the generator
7.2.5. Replacement of the regulator of tension
7.2.6. System of start of the engine - the general information and precautionary measures
7.2.7. Removal and installation of a starter
7.2.8. Replacement of the traction relay
8. Manual box of gear shifting and coupling
9. Automatic transmission
10. Cardan and power shafts, reducer, differential and stupichny assemblies
11. Brake system
12. Suspension bracket and steering
13. Body
14. Onboard electric equipment
15. Schemes of electric equipment


7.2.2. The rechargeable battery - the general information, recommendations about service

The rechargeable battery installed on the car consists of six cans in which positive and negative plates (lamels) shipped in solution of sulfuric acid are placed. The main task of the battery is production of the current necessary for implementation of start of the engine, ignition of working mix, lighting, and also for providing other onboard or auxiliary consumers of the electric power with food.

In winter conditions, at temperatures below-18 a hail., efficiency of recharge of the battery decreases in view of increase of its internal resistance. At short trips in the winter the energy spent by the battery for start of the engine does not manage to be restored, and the battery begins to work very hard, being gradually discharged and, eventually, fails is irreversible.

In the summer at long trips the engine strongly heats up, and often happens that it is difficult to start it anew. Not less energy of the battery, than in frosty weather is sometimes spent for such "hot" starts. Told in a special measure treats high-compression engines with the large working volume of cylinders, and also the models equipped with the К/В system.

Additional information on the rechargeable battery is provided in the Section Check of a Condition of the Battery and Leaving behind it of the Head Nastroyki and routine maintenance of the car.

Acquisition of the new rechargeable battery

Told above states on importance of correctness of the choice of the rechargeable battery taking into account parameters of the engine and a complete set of the vehicle. Upon purchase of the new rechargeable battery it is necessary to pay attention to its performance data:

  1. Rated output voltage. Has identical value (12 V) for all batteries used on cars that practically excludes probability of a mistake.
  2. The capacity measured in Ampere-hours (And • h) and, roughly speaking, defining a stock of the electric power which is contained in the battery. Depends on the choice of size of this parameter as long the battery is capable to provide a possibility of a provorachivaniye of the engine with a starter, more precisely - how many it is possible to make attempts of start of the engine. The price of the rechargeable battery is almost directly proportional to its capacity.
  3. Starting current (A), i.e. the current given on a starter at start of the engine. The size of starting current on batteries can be specified according to four different standards: GOST (for domestic accumulators), EN (the standard of Uniform Europe), SAE (the American standard) and DIN (Germany). The last, German standard, is closest to the Russian state standard specification and on the majority of batteries of the European production is put down "by default" i.e. when the system of the standard is not specified. The starting current is higher, the big turns are developed by a starter and the he is capable to transfer bigger torque to an engine flywheel.

Ideally, the acquired replaceable battery on the performance data has to conform completely to requirements of Specifications at which observance service life of the battery will be maximum. Acquisition of the battery of smaller capacity can hardly be considered good economy of money as it will serve much less and, besides, can lead to the unpleasant efforts connected with start of the engine in winter season. It is not necessary to buy the battery with excessively big starting current, - such hobby is accompanied by risk of failure of a starter. If the standard battery does not provide a due provorachivaniye of the engine, it will be more correct to make for a start replacement of motive oil, - that, most likely, will lead to automatic elimination of a problem.

There are several signs on which it is possible with sufficient degree of probability to distinguish the original from a fake. The first and, perhaps, main thing: on the case of the battery the country manufacturer and the manufacturing plant have to be surely specified, it is better if with the address. The second: date of production has to be specified that special value has for batteries of tight (unattended) type. Technical data sheet while existence of the instruction is not strictly obligatory surely has to be included in the delivery package. The third: high-quality batteries differ in good appearance. The case has to have smooth edges, to be equipped with reliable traffic jams and the smooth, covered with protective caps polar plugs which quite often become covered by a layer of special anticorrosive lubricant.

Battery charging

Charging of the failed battery should be made according to instructions of manufacturers of the charger.

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7.2.1. General information
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7.2.3. System of a charge - general information and security measures