If the red battery light on your car’s dashboard starts blinking, then take it as a sign that your battery or charging system is not functioning properly.
The battery warning light is in the shape of a battery symbol, usually with a plus and minus sign. There are a few reasons why the battery warning light might come on, from a loose or corroded battery cable to a faulty alternator, we’ll explore the possible causes and fixes below.
Why Is My Car Battery Warning Light On?
The car battery warning light indicates there is a problem with the vehicle’s battery and/or charging system. Your car battery could be low on charge, or there could be another issue with a different component. If the light comes on when you turn on the ignition or appears while you are driving, you need to investigate further. If you’re worried about flashing warning lights on your dash, it’s usually a good idea to book a diagnostic check. One of our trusted mechanics will help you get to the root of the problem.
What is the Car Battery Warning Light?
A battery warning light is one of the several car safety management indicators on your dashboard. That red battery light on the dash is specially designed for issuing immediate warning signs to the driver, if and when something goes wrong with the car battery or a part that’s directly linked to it.
What Does it Mean When the Car Battery Warning Light is Flashing?
If you see the orange or red battery light on, it means that you should stop your car as soon as it is safe to do so and check your car’s battery. However, if the car battery warning light comes on while you are on the road, do not stop the car right away.
Battery issues may make it difficult to get a car started again, so keep driving at a moderate speed until you reach the nearest service centre or repair garage. If the engine has stalled and you can’t restart it, call an auto recovery service.
How Does the Car Battery Warning Light Work?
The car battery light on the dashboard should look quite similar to the battery icon on your smartphone or laptop. The shape and size may vary a bit depending on model and make, but all car battery warning light indicators should have a + and a – sign enclosed within a (somewhat) rectangular battery shape.
When you notice the orange battery light on intermittently, it means that the problem is not yet severe, but your car still needs professional attention at the earliest to prevent the concern from escalating. However, if you see the red battery light staying on or flashing continuously, that means your car requires immediate attention.
Act soon after noticing your car battery warning light coming on and off intermittently for the first time. Not all car safety monitoring systems can detect a battery issue unless the problem is already quite serious, so it is safer to treat it as an urgent situation whenever the car battery warning indicator comes on.
What are the Common Reasons the Car Battery Warning Light Will Come On?
A blinking battery light on the dashboard is often accompanied by dimming headlights. Both of which can be a result of one or more of the following problems.
Alternator Malfunction
The alternator charges your car battery in synchronisation with a built-in voltage regulator. When this charging system starts to malfunction, the red battery light on your dash will start blinking to warn you in advance. This is a key component in any car, so you may need to replace your alternator if it’s faulty. If your battery warning light is on, this may indicate:
- The alternator is failing to charge your car battery within the optimal volt range.
- The built-in voltage regulator is malfunctioning, which can mislead the alternator into overcharging and consequently, damaging your car battery.
Cracked Alternator Belt
Alternator belts will start to crack after about 80,000 – 140,000 miles, depending on one’s driving habits, regular terrain quality, and maintenance standards. Each time a charge escapes through those cracks, your battery warning light will try to notify you. These attempts will continue to turn your battery light on intermittently until you get the alternator belt changed. Be warned that the cracks will eventually lead to the belt breaking completely.
Broken Alternator Belt
Replacing a cracked alternator belt is an easy fix, but do not wait until the belt breaks in the middle of a journey. If the irregular flashing is followed up by the battery warning light staying on or steadily blinking at regular intervals, it probably means that your alternator belt just broke. At this point, you will not be able to charge your battery or even start the car without changing the broken belt first. Book an alternator belt repair as soon as you see that red battery light starts flashing sporadically.
Damaged Car Battery Terminal
If the battery terminal itself is corroded, it will lose some of its electrical conductivity. This will turn your red battery light on in the same way as it would in case of a failing alternator. Even if the alternator is brand new, it will not be able to charge a damaged battery terminal properly. Battery posts generally take a long time to corrode, but it can happen faster when overexposed to leaking electrolyte solutions, overheated engines, hydrogen exhausts, and moisture damage (snow, rain, humidity).
Dead Battery
If the reason behind your car battery warning light flashing or just staying on all the time is a dead battery, then it can mean any of the following:
- You have ignored the battery warning light long enough for the charge to go down completely to 0.
- The car is running on an expired battery that cannot hold a charge anymore.
Car batteries do not usually last for more than 4 – 6 years. If the battery warning light is coming on far too often even after getting regular maintenance checks, your car battery needs replacing.
Is It Dangerous to Drive with My Car Battery Warning Light On?
If the battery warning light is coming on and off intermittently or blinking occasionally for the first time, it should not yet be a cause for panic. In fact, it is safer to continue driving to a nearby service centre or a local mechanic for a check-up if you are already in the middle of your trip.
At the same time, it can be dangerous for drivers who ignore their flashing battery warning light for too long. If the engine stalls, you might not be able to restart it. Also, driving with dimmed headlights at night leads to hundreds of accidents every year.
Will My Car Fail MOT If Its Car Battery Warning Light is on?
The short answer is yes. If MOT inspectors see your car’s red battery light on, it will most likely fail the test. As clearly stated on the government website, all visible electrical wiring and the car’s battery will be checked thoroughly. Given that a battery warning light is an assurance of the fact that something is amiss with the battery, get it checked and fixed before your MOT.
About Fixter
Fixter is revolutionising the car maintenance industry, one repair at a time. Fixter was founded to make car maintenance as easy as booking a taxi. Digital, transparent and stress-free, with world-class customer service. Since launching in Manchester in 2017, Fixter has expanded to more than 100 towns and cities across the UK and provided thousands of car owners with honest, convenient and affordable car repair services.