How to Know If Your Car Battery Is Dead? A Complete Guide!
A car battery is the primary source for a traction motor and other electronic components to get electric power. Simply put, a battery provides the power to start an electric vehicle.
Each battery comes with a specific life cycle; after which it fails to perform properly. For example, a dead battery can power up low-power electronic components in the car, but it will not be able to start the car. Therefore, it is important to recognize a bad or dead battery early.
A dead battery can cause common issues, including but not limited to random illumination of warning lights, auto start/stop failure, spontaneous alarm activation, and inconsistent stereo operation.
So, if you are wondering how to know if your car battery is dead, this article explains it in detail, including signs of a bad car battery, how you can test, and when to replace it. Let's get the discussion started.
Potential signs of a dead car battery
This section explains how to tell if a car battery is dead. It presents the eight potential dead battery symptoms you should be familiar with. Let's read through them one by one.
1. No start
In this situation, the radio and lights work, but the car does not start. The headlights can be dim, too. The primary purpose of a car battery is to provide enough power to the engine so that it can start properly and immediately. When your battery is low or dead, it will not be able to start the vehicle properly but can power up low-amperage accessories.
If you are stuck in this situation, you can jump-start your vehicle. However, it is recommended only if you have an emergency. Otherwise, get your car battery tested on priority before you do anything else.
2. A slow start
The starting of an electric vehicle drops down in cold temperatures, usually below 20 degrees Celsius. If the temperature is below 0 degrees Celsius, the vehicle will start even slower. If you notice that there is no drop in the temperature but the car starts slowly, it is possibly due to a dead or bad car battery. Therefore, get the battery tested immediately.
If your battery takes the charge properly on slow charging, the slow start may be due to the battery discharge when the car sits. Ask the technician to check the electrical system of the car, too. If there is any other issue, it will be highlighted during the test.
3. Swollen car battery
A manufacturer designs the battery in a special style. If you notice that the structure is swollen, it is possible that your battery can be dead. The structure of the battery can be bloated due to overcharging, too.
Overcharging happens when hydrogen gasses build up faster than a car battery dissipates them. The damage to the car battery can't be reversed, as it is permanent.
4. Old battery
The average car battery lifespan falls somewhere between two and five years. If your battery is older than the mentioned lifespan, consider it as an old battery. Especially, if your battery is four years older, you must pay close attention to its performance and keep a regular check.
You can go to a car technician to get the battery tested. Doing this will help you know how much charge the battery has. Some auto service centers provide this service for free.
5. A rotten egg smell
By design, a battery produces no smell. Therefore, if a smell like rotten egg is coming out of your car battery, it shows that the battery has vented gas, and it is one of the dead battery symptoms.
When a smell comes out, the battery also releases sulfuric acid, which is dangerous to the other parts of your vehicle's engine. If you don't fix this problem on time, it could be the costliest issue. Usually, it is recommended that you replace your old car battery with a new one.
6. Car starts but dies
In some car models and makes, this issue is common. The car battery can provide enough power to start the vehicle, but it dies immediately. If you are experiencing the same issue, there can be multiple reasons behind it. However, getting your battery tested should be your number-one priority.
The reason why the car starts but dies is because of the battery, causing interruptions to constant signals that are sent to the ECU. Though the battery provides enough spark to start the vehicle, fueling, speed, and engine-controlling sensors have already lost their signals, which is why your vehicle dies immediately.
7. No radio
When the car starts, the battery powers up everything, including headlights, windshield wipers, radio, and other electronic components. If you notice that the radio is not turned on, don't consider it a minor issue. It could be the leading symptom of a dead battery. Or if all electronic devices dim or flicker, go to a car mechanic for a quick battery checkup.
8. Check Engine Light flashes
If the Check Engine Light constantly stays on or flashes, it could be a serious issue that may need expensive maintenance. But if you discover that it is just because of the dead battery, consider yourself a lucky car owner. Replace the battery immediately and enjoy the ride. Many auto shops or service centers offer free diagnosis of vehicles. You can go to similar spots for trusted checkups.
Symptoms of a bad or weak battery
Now that you are familiar with the signs of a dead battery. It is time to explore the most common weak or bad battery symptoms. Below we have listed a few signs of a bad battery. Let's read through them.
1. Clicking sound when starting a car
Do you notice a clicking sound when you press the start button to start your vehicle? If so, this is due to the weak or bad battery. Check how much charge it has. It would be too low of course. If yes, get it charged on priority with an external charger or go to a mechanic for battery checkup.
2. Illuminated warning light on the dashboard
Many cars come with a warning indicator on the dashboard. This indicator is denoted with the car battery symbol. When your car battery does not charge properly, the indicator turns on. If you see that the warning indicator is turned on, go for a quick battery inspection instead of taking it for granted.
3. The swollen battery case
When a car battery is exposed to extreme cold or hot temperatures, its case can swell. Therefore, if you have taken your car to an extremely hot or cold environment, it is always better to look at your battery case.
The swollen case could lead to a completely dead battery. If this is the case, find a new battery for your vehicle and replace it right away.
4. Electrical components not performing well
Modern cars are equipped with a wide range of electrical and electronic components. Each needs a specific amount of power to function properly. This power is taken from the car battery.
If you see that the components are not performing in the way they are supposed to, consider it as one of the leading signs of a bad battery.
5. Dimming headlights
Headlights are one of the most important components of your car, as they ensure safe travel at night. They allow others to see your vehicle and enable you to see them, too. This is how you can avoid any sort of collision or accident in the presence of bright headlights.
Headlights dim when they do not get enough power they need to illuminate properly. So, if the headlights are not shining brightly, ask the mechanic to perform a quick checkup to see if it is due to a weak battery. If so, fix it immediately.
6. Slow engine crank
A good battery provides the starter with enough electrical power, which is then converted into mechanical energy to start the car's engine. If you notice a slow engine crank, it is possibly due to a weak or bad battery. Get the battery inspected and fix this issue.
How to test if your car battery is dead?
Auto service shops can check the battery voltage to tell if it is dead. You don't necessarily visit these shops to get this job done. You can also check the voltage level on your own. All you need is a voltmeter or multimeter and a basic understanding of this tool.
Set the measuring range of the voltmeter to 15-20 volts. Then, connect it to the positive and negative terminals of the battery. If you don't know how much the voltage level should be, you can look at the manufacturer's manual to get a clear idea. Normally, a fully charged battery shows a voltage of 12.6 volts. If your battery's voltage is lower than 12.6, it means it is dying.
Start the car and see if the voltage is above 10 volts. If it is below 5 volts when the vehicle is running, you need to replace the car battery immediately, as it is dead.
The second method to check the health of the battery is to consider its age. Once the battery crosses the period of its lifespan, it loses the capacity to hold the charge. If you have an old battery, it may create some identifiable problems.
If the battery is not dying but you are still worried about its life, see if the headlights flicker or the engine takes longer to start. They both are the leading reasons associated with a weak car battery. To understand what exactly the issue is, get your battery tested.
Common causes of a dead or bad car battery
There are several causes of a bad or dead battery. A few of them are as follows.
- Older batteries tend to lose their ability to hold the charge, which leads to their death with time.
- The malfunctioning car charging system can affect your battery's health. If you see a battery warning, you should also look at the alternator belt, terminals, battery cable, serpentine belt, and alternator to see if they are working properly.
- Corrosion on your car battery terminal is another leading reason behind a dead or bad battery.
- Sometimes, manufacturing defects may also be a potential cause of a dead car battery.
- A simple user error may also result in a dead battery. For example, when you unintentionally use too much accessory power during a short drive, leave some accessories on charging or leave overhead lights on.
Tips to prevent a dead car battery
Here is how you can keep your car battery away from dying when it is not in use.
- Disconnect the battery from the circuit. Or disconnect the negative terminal only. It will prevent the battery from draining parasitically.
- Buy a battery maintainer or a trickle charger to add a slow charge when you don't drive the vehicle.
- Avoid too many short drives.
- Unplug unnecessary accessories.
When to replace your car battery?
It actually depends on the lifespan and warranty of your car battery. After every charge, the performance of a battery slightly deteriorates just like the batteries installed in laptops or mobile phones.
Usually, it is recommended to replace a battery after every three years. However, some batteries come with a longer lifespan and run perfectly for several years. You can keep an eye on their performance to determine if they are losing the capacity to hold charge.
Conclusion
“How to know if your car battery is dead?” is one of the frequently asked questions. If you notice a slow start, the engine starts but dies immediately, a bloated battery case, a smell coming out of the battery, dimming or flickering headlights, or no radio, it is a clear indication that the battery is drying or dead already.
If you want to know more about the signs of a bad battery, read the discussion above. This article has also presented some valuable tips to prevent a bad or dead battery. If you are wondering when to replace the battery in your car, look at the battery's lifespan to make a worthy decision. If you need a reliable car battery, contact Renogy.
FAQs
Will my car still start with a dead battery?
If you have a dead battery, it will not help you start the vehicle. You will either need to replace the battery or jump-start your car.
What happens when the car battery is out?
When a car battery is dead, you will not be able to start the car's engine. Similarly, the headlights die, or they do not shine as brightly as they should. In addition, you can't turn on the radio.
How does a car act with a dead battery?
In case of a dead battery, an electric car does not start. Moreover, it does not allow all electrical and electronic components to function properly in the presence of a low power source.
