When cars show signs such as difficulty starting, dim headlights or abnormal electrical system operation, many car owners often wonder if the cause is from the battery or generator.
Accurately identifying the faulty part helps save repair costs and avoid unnecessary replacement.
The role of batteries and generators
Batteries are the main power source used to start the engine and supply electricity to devices when the car has not started. The average lifespan of car batteries usually ranges from 3 to 5 years.
Meanwhile, the generator is responsible for recharging the battery and supplying electricity to the entire power system when the engine is operating.
The lifespan of generators is usually longer, about 7 to 10 years depending on usage conditions.
Because they are both involved in the electrical system, the symptoms of damage of these two parts are sometimes quite similar.
Signs of battery degradation
The most common symptom of a weak battery is slow engine start. When turning the key or pressing the start button, the car takes longer than usual to start the engine.
Frequently having to drain the battery or electric shock to start the car is also a sign that the battery no longer holds electricity well.
The headlights are weaker than normal, the entertainment system operates intermittently, or a "click" sound appears when starting the engine may also be related to the power from the battery.
Another easily recognizable sign is that the battery shell is inflated. This phenomenon often appears when chemical reactions inside the battery occur abnormally or when the battery is over its age.
If the battery has been in use for more than 5 years, car owners should check it periodically to avoid the risk of unexpected damage.
Warning signs of a power generator malfunction
Unlike batteries, generator breakdowns are often clearly shown when the engine is running.
One of the most common signs is that the battery is constantly out of battery even though it has just been charged or replaced. This shows that the generator is no longer capable of effectively charging.
In addition, the battery warning light or the charging system on the dashboard running continuously is also a signal that needs to be checked immediately.
Drivers can also notice phenomena such as bright and dark headlights, flickering entertainment screens or unstable electrical equipment.
In some cases, a generator with worn bearings or mechanical damage will emit awkward sounds, abnormal grinding sounds from the engine compartment. If a burning smell or smell of burning rubber appears, the cause may be that the generator overheats.
Simple home test
Car owners should check the voltage with a universal meter. A healthy battery when the car turns off usually has a voltage of about 12.6V. When the engine is running, the charger system voltage is usually in the range of 13.5V to 14.5V.
The car owner can perform an electric shock test. If the car starts after firing the cylinder but quickly stalls when removing the power supply, it is likely that the generator is having problems.
Conversely, if the car continues to operate normally, the cause usually comes from a weak battery.
