1. Driver’s carelessness
With the engine off, power consumers remained on for a long period of time: low beam, tail lights, defroster lines on windows and mirrors, seat heater, interior lighting, trunk or glovebox lighting, etc.
2. Generator actuator malfunction
Generator belt tension required mandatory assessment, since its slipping results in reduced generator power and fast discharge of the battery. Tightening is required if the belt gives by more than 15 mm when pressed with a finger.
3. Generator malfunction
while idling, with low beam and interior heating fan on, a fault-free generator produces voltage of 13.9–14.3 V. Voltage deviation is a sign of generator malfunction: broken regulator, rotor winding break, burnt diode bridge, broken fuses in the mounting block, worn generator brushes, decayed starter winding.
4. Leakage in the automobile electric power circuit
With serviceable electrical equipment, leakage currents should not exceed 10 mА. Such leakage does not have a negative effect even when the car is parked up to 3 months. Large leakage currents occur as a result of unqualified connection of electrical equipment: alarm, car stereo, radio, etc. Make sure that the car wiring is in good working condition, check the integrity of the insulation, all contacts and connections should be securely attached.
5. Excessive load on vehicle network
Use of additional power consumers that were not intended by the automobile manufacturer: additional lights, high power low and high beams, powerful audio equipment, etc.
6. Late maintenance of the battery
Always check that the battery contacts pieces are tightened, wires are not loose, and terminals are clean. If terminals are covered with oxide, it would be good to clean them with emery paper. Disconnect contacts from the negative and positive poles of the battery, clean the terminals with fine abrasive. The battery surface should also be free of oxide. If necessary, wipe it with cloth.
7. Short trips. Engine operation at low gears
If you normally make many short trips, most of which occur in the city in traffic jams, the battery will not have the time to charge sufficiently. Remember that many car generators are designed to start charging the battery only when the engine rpm value reaches one and a half thousand. The more powerful electricity consumers you switch on (rear window defroster, phone charging, music, amplifier, etc.), the less voltage remains for your battery.
Reasons for battery fast discharge
1. Driver’s carelessness