A flat, or discharged, battery can be a real pain when you go to start your car in the morning before work. As aggravating as this can be, there are additional issues to consider when dealing with a car that has a battery that is not properly holding a charge.
When your battery is not performing optimally, it can affect various components of your car and may lead to further complications if left unchecked. While a flat battery may seem like a minor inconvenience, there are significant impacts on fuel efficiency and the overall functioning of your vehicle’s electrical systems.
Impact on the Alternator
The alternator charges the battery and continues to try to charge the battery while the car is running. If the voltage level does not reach an acceptable amount, normally around 12 volts, the alternator may run non-stop during your entire drive. Since the alternator is linked directly to the drive or accessory belt that is turned by your engine, the added resistance of the alternator working can cause a slight decrease in fuel economy.
While this decrease in fuel efficiency might be too small for most people to realise, it’s not just the fuel economy that suffers. The continuous operation of the alternator places strain on it, which could result in a shortened lifespan. Replacing an alternator is a costly repair, so it’s better to ensure that your battery is in good condition to prevent the alternator from overworking.
Fuel Injector Efficiency
Without a properly charged battery, the fuel injectors may not add fuel to the cylinders as efficiently as they normally would. This inefficiency can result in a noticeable reduction in fuel mileage, more so than the alternator simply running all the time. You may notice the engine lurching or the car running a bit rough. This is sometimes an indication that a quick check of the battery is in order.
The battery plays a critical role in providing the power needed for fuel injectors to function properly. If the voltage from the battery is too low, the injectors may fail to deliver the optimal amount of fuel to the engine, leading to poor performance and higher fuel consumption.
Effect on the Car’s Computer and Sensors
The car’s computer will normally continue acceptable operation, but other accessories will place additional load on the vehicle’s electrical and mechanical system. The oxygen sensor and other exhaust gas sensors may not work effectively on a lower voltage than recommended by the manufacturer. In this event, the computer will be unable to accurately gauge whether fuel consumption matches the rate of exhaust produced.
- This mismatch between fuel consumption and exhaust production can cause inefficiencies in fuel use, leading to increased fuel wastage.
- Lower voltage can also prevent the car’s computer from optimising the vehicle’s performance, resulting in decreased engine efficiency.
For cars equipped with cylinder deactivation technology, which allows some of the engine’s cylinders to shut down during low-intensity driving (such as city driving), the battery’s performance is even more crucial. If the computer does not receive the necessary electrical information from the vehicle’s sensors due to a flat battery, it won’t be able to activate cylinder deactivation, causing a noticeable drop in fuel efficiency.
Conclusion
A flat or poorly charged battery can lead to far more than just the inconvenience of a car that won’t start. From overworked alternators and inefficient fuel injectors to sensors and computers unable to optimise performance, the impact on your vehicle can be significant. Maintaining your battery in good working order is key to ensuring optimal fuel efficiency and extending the life of various components in your vehicle.
If you suspect your battery is not holding a charge or notice signs such as rough engine performance or decreased fuel mileage, it’s time to have it checked by a professional. Regular maintenance can prevent unexpected breakdowns and help keep your vehicle running efficiently.
