Battery — General information, maintenance recommendations (Audi A4 B7)

Table of contents: Purchasing a new battery ↓ Charging the battery ↓

1. The main task of the battery is to generate the current necessary to start the engine, ignite the working mixture, provide lighting, and also to provide power to other on-board or auxiliary consumers of electrical energy.

2. In winter conditions, at temperatures below -18 degrees, the efficiency of battery recharging decreases due to the increase in its internal resistance. During short trips in winter, the energy expended by the battery to start the engine does not have time to recover, and the battery begins to wear out, gradually discharging and, eventually, failing irreversibly.

3. In summer, during long trips, the engine heats up a lot, and it often happens that it is difficult to restart. Such "hot" starts sometimes consume no less battery energy than in frosty weather. This applies especially to high-compression engines with a large working volume of cylinders, as well as to models equipped with a climate control system.

4. For more information about the battery, please refer to Section 17 Chapter 1; a description of starting the engine from an auxiliary battery is given in the Chapter "Controls and operating techniques".

Purchasing a new battery

5. The above indicates the importance of choosing the right battery, taking into account the engine parameters and vehicle configuration. When buying a new battery, you should pay attention to its performance characteristics.

a) The nominal output voltage has the same value (12 V) for all batteries used in passenger cars, which virtually eliminates the possibility of error.

b) Capacity, measured in ampere-hours (A h) and, roughly speaking, defining the reserve of electric energy contained in the battery. The choice of the value of this parameter determines how long the battery is able to provide the ability to turn the engine with the starter. The price of a battery is almost directly proportional to its capacity.

c) Starting current (A), i.e. the current supplied to the starter when starting the engine. The value of the starting current on batteries can be specified according to four different standards: GOST (for domestic batteries), EN (standard of the United Europe), SAE (american standard) and DIN (Germany). The latter, German standard, is closest to the Russian GOST and is indicated "by default" on most European-made batteries, i.e. when the standard system is not specified. The higher the starting current, the higher the speed of the starter and the greater the torque it can transmit to the engine flywheel.

6. Ideally, the battery you purchase should match the factory-installed battery in terms of its performance characteristics, which will maximize the battery's service life. Buying a battery with a smaller capacity is hardly a good way to save money, as it will last significantly less and, in addition, may lead to unpleasant troubles associated with engine starting problems in the winter. If the standard battery does not provide proper engine cranking, it would be better to start by changing the engine oil, which will most likely automatically eliminate the problem.

7. There are several signs by which you can distinguish an original from a fake with a fair degree of probability. First and perhaps most important: the country of manufacture and the manufacturing plant must be indicated on the battery case, preferably with the address. Second: the date of manufacture must be indicated, which is especially important for sealed batteries (unattended) type. The delivery set must include a technical passport, while the presence of instructions is not strictly required. Third: high-quality batteries are distinguished by a good appearance. The case must have smooth edges, be equipped with reliable plugs and smooth, covered with protective caps pole terminals, which are often coated with a layer of special anti-corrosion grease.