A dead battery means your car won’t start, resulting in dim headlights and an unresponsive engine. This can be a real problem if the battery fails in the middle of nowhere or in the morning when you’re already late for work. What drains a car battery? Are you curious about what the reasons might be?
What Can Drain a Car Battery?
Many of us wonder what causes your car battery to drain. Contrary to popular belief, many things can happen and lead to a dead battery, even if you are already equipped with top-rated car batteries. Read on and discover the 6 most common reasons that can drain your car’s battery.
1. Leaving Lights On
Leaving the headlights on is one of the reasons why a car battery dies. It’s a mistake every driver has made at least once in their life, as they wonder more than once, “what could be draining my car battery?“. You’ve come home from work very tired and rushed into the house leaving the headlights on or the trunk open, causing the battery to drain overnight.
Even small dome lights can significantly drain the car battery. Or, after parking your car at home, you forget to turn off the light and the car battery drains overnight. So, make sure you haven’t left any lights on before closing the door behind you.
2. Electrical Problems
If someone asks you, “What drains a car battery when the vehicle is off?“, electrical problems are the answer you should keep in mind. Even when you turn off the ignition, some functions continue to operate. It’s normal for the security alarm, clock, and radio presets to be operational at all times. However, other components can be powered on in case of an electrical issue. For example, parasitic drain can extend to the trunk and glove compartment lights, which normally stay off.
3. Weak Battery
Poor maintenance can weaken a battery, which may not hold its charge for long, and this is what makes a car battery die quickly. It will be vulnerable to all conditions. Even small drains like the clock or the radio’s memory function can kill it. Furthermore, such a battery does not withstand extremely hot or cold temperatures well. So, take care of it if you don’t want to end up with a dead car in the morning.
Note: A battery maintainer is an effective solution for battery maintenance. A maintainer charges a battery slowly and avoids overcharging. Therefore, if you need to buy one, here is the list of recommended top battery maintainer products to buy for you.
4. Corroded or Loose Battery Connections
This is another consequence of irregular maintenance. Loose or corroded connections prevent the charging system from working properly. This can drain the car battery even while you are driving. Many car models use the alternator to charge radios, clocks, lights, and other small components. In this case, a charging problem can worsen the drain. If the battery is not charging correctly, you should have it diagnosed by a professional mechanic.
5. Faulty Alternator Diode
Another answer to the question of what drains a car battery is a faulty alternator diode. The alternator’s function is to power several electrical systems and recharge the battery. If its diode is corroded, the circuit will consume power even when the engine is not running.
6. Old Battery
If the car consistently has trouble starting, the problem could be a worn-out battery. An old battery is the final reason that drains a car battery. Typically, car batteries have a lifespan of 4 to 5 years. So, if you often face the problem of a dead car battery, it’s probably time to buy a quality battery. Changing to a new battery is the right choice for you by going to a trusted garage.
What Drains a New Car Battery?
The normal lifespan of a car battery is about 3 to 4 years. After that, the battery may start to wear out and need to be replaced with a new one. You have a new battery for your car but find that your battery keeps dying? Here are 3 reasons for this:
1. Driving Too Many Short Trips
If you often drive your car on short trips, this can be a reason why your car battery drains. It’s not surprising that your battery tends to die too early. The main function of the car battery is to power the vehicle’s ignition. Driving too many short distances means your alternator doesn’t have enough time to recharge between your vehicle starting and stopping. Little by little, this drains your battery and it doesn’t last as long as it should.
2. Extremely Hot and Cold Weather
If the temperature rises too high (above 100 degrees) or drops too low (below 10 degrees Fahrenheit), it will negatively impact your car battery. Leaving your car in these bad temperatures for a long period will lead to a buildup of lead sulfate crystals. Sulfate buildup is one of the main reasons that reduces your battery’s lifespan and increases the recharge time it needs.
3. Faulty Charging System
What drains a car battery can be a faulty charging system. To recharge your car battery, your vehicle’s alternator needs to supply it with power. If some parts of the system fail, it’s not surprising that your car battery dies too early.
What Happens If Your Battery Drains?
If you have a dead battery and you don’t address it, it will discharge to 0% and be dead. Most of the time, you therefore won’t be able to start the engine. Imagine you’re driving on the highway and you have a dead battery. You’ll be in trouble since everything will be delayed and it will also affect other drivers. Or you’re about to go to work or an appointment but your engine won’t start? What a bad day. So, consider checking your car or going to the garage to ensure your car is always running.
How to Detect a Battery Drain
It’s frustrating to have a battery that doesn’t hold a charge, and it can be difficult to determine the cause of the problem. Since the cause of the battery drain is not human error, you will need the help of a qualified mechanic who can diagnose your car’s electrical problems and determine if it’s a dead battery or another issue in the electrical system. Otherwise, you can also learn these tricks to do at home.
1. New Battery
If your battery is still new (car batteries have a lifespan of about six years), a jump start should be enough to get you going. This solution is provided with jumper cables or a standalone jump starter stored in the truck. Since the battery is in good condition, it will receive electricity from the other battery and then recharge properly.
- Park and turn off the car with a jumper cable next to the dead one. You need to open the hoods of both cars and take out the jumper cables. You should also protect your hands and eyes in case of a problem.
- Connect one end of the red (positive) jumper cable to the red terminal of the dead battery.
- Connect the other end of the red cable to the red terminal of the charged battery.
- Connect one end of the black (negative) jumper cable to the black terminal of the charged battery. And the other end to an unpainted metal part in the dead car, away from the battery. This safety measure grounds the circuit to prevent sparks.
- Start the car with the charged battery. Let the engine run for 5 to 10 minutes.
- Try to start the car with the previously dead battery. If it starts, let it idle for at least 20 minutes if you don’t plan to drive immediately. If you need to start right away, drive for at least 5 to 10 miles to fully recharge the battery.
Before taking off, remove the battery cables in the reverse order of how they were attached. This means the black cable attached first to the metal ground, and so on.
2. Old Battery
A new battery is all you need here. However, it’s best to determine if it is indeed your battery and not something else before spending over $80 on a new one.
There are a few common signs of a faulty battery. An obvious sign would be a complete absence of lights or cranking when you try to start the car. Another sign would be the engine cranking furiously without actually starting. This one is less obvious but happens more often than not, it’s the battery.
It’s easy to jump straight to towing the car to a garage if it won’t start, but you’ll spend less time and money by doing a little self-diagnosis.
Note that you will probably be able to jump-start a dead battery to go somewhere, but chances are it won’t start on its own if you try again with the same faulty battery (i.e., don’t strand yourself somewhere).
Sometimes the battery can be so damaged that it can no longer recharge enough for a jump start. The best way to know for sure is to take your battery to a store that performs free battery tests. Auto parts stores like O’Reilly, Autozone, and Advance Auto Parts all offer this service. You can then buy a new one on the spot if needed.
What Should You Do to Avoid Draining Your Battery?
- First, make sure to turn off all interior lights and not leave anything on before leaving the car. Similarly for the radio, you should turn it off if you’re not driving. Interior lights and radios left on can drain the battery.
- Second, keep the battery clean. This is very important and you should do it frequently. Use a dry cloth to wipe away any dirt or residue near the terminals and connection areas. A dirty battery can sometimes be the cause of its damage.
- Third, remember to check the cable connections to the battery. The connection should be tight and clean. A loose or dirty connection between the cable and the battery can cause the battery to drain.
- Fourth, use a portable car battery charger or a jump starter and charge the battery if it’s below the performance level. The charger can be found in an auto shop where you can find other things besides just the charger. Remember to use the charger’s jumper cable to test the battery’s power.
- Finally, taking your car to the garage for annual maintenance will help you avoid what drains your car battery. The specialist will check and, if necessary, replace the battery for you.
Summary
As you can see, both new and old car batteries can drain if you don’t take proper care of them. We hope that after reading this article, you have an in-depth understanding of most of the reasons why your car battery keeps dying and know how to handle them. If you have any questions about “what drains a car battery” or about cars, feel free to leave us a comment in the box below.