6.2.1. Rechargeable battery
The battery installed 12 V consists of six cans containing positive and negative plates which are lowered in solution of sulfuric acid. The problem of the battery includes production of current for start of the car, ignition and for lighting, and also for other consumers of the electric power.The battery possesses 100% efficiency at 27 °C. At –18 °C efficiency falls to 40%. Now to start the engine, it is necessary to have more than twice more energy, than it was necessary at 27 °C.
Starting power (starting current) shows ability of the accumulator to start the car in the conditions of very cold weather. It shows current in amperes which gives the accumulator within 30 seconds at –18 °C without power failure lower than 7.2 volts (the minimum level demanded for reliable start). The this indicator, the more starting power of the accumulator is higher.
Reserve power shows time in minutes during which the accumulator gives current of 25 Amperes at 27 °C, i.e. time during which the accumulator ensures functioning of all auxiliary devices in the car at night and in the conditions of bad weather at the faulty generator.
In winter conditions at –18 °C and below the battery will be badly charged in connection with increase of internal resistance. At short trips in the winter the energy spent by the battery for start is not restored. As a result the battery works very hard, is constantly discharged and eventually fails.
In summer months after long trips the engine strongly heats up, and often happens that it is difficult to start it anew. Such "hot starts" sometimes demand as much the power how many and at cold weather, or it is more. It especially extends to high-compression engines with large working volume and cars with the conditioner. It once again emphasizes importance of a right choice of the accumulator according to the car engine.