Can Timing Belt Drain Battery? [Yes! But Here’s What You Need to Know]

No, timing belts can’t drain the battery, but they can affect the alternator’s performance. The serpentine belt controls the alternator, as well as other components such as power steering and AC. The engine cannot run without a timing belt, and the serpentine belt cannot run without the engine.

Are you looking for the cause of your vehicle’s battery drain? It can happen for many reasons, but the primary reason for battery draining can be related to the engine belts.

So, this will be discussing can timing belt drain battery.

Let’s discuss in more detail whether the timing belt can drain the battery.

Can Timing Belt Drain Battery?

The timing belt cannot drain the battery but it can prevent the alternator from properly charging the battery. Timing belts are responsible for rotating the engine internals in sync. It’s the alternator device that charges your battery, and a serpentine belt controls the rotations of the alternator. Hence, if the serpentine belt fails, the charging fails.

Serpentine belt problems will not only affect battery charging, but also other systems attached to it, such as power steering and AC compressors. So, inspect both the timing and serpentine belt when you’re experiencing a battery drain in your vehicle.


The timing belt rotates the engine internals, whereas the serpentine belt primarily controls the rotation of the alternator. So, If the serpentine belt wears out or is damaged, the alternator will eventually lose the capability of charging the battery.

How to Diagnose Faulty Engine Serpentine and Timing Belts?

If you have a faulty timing belt, you should immediately replace it for engine safety. Here’s how to thoroughly diagnose your timing belt:

  1. First, visually inspect the serpentine and timing belt. Look for any cracks, rips, or fraying.
  2. Check the tension of the belt. If it’s too loose, it can slip and cause damage.
  3. Ensure there’s no oil leaking on the belt. Oil leaks can cause belt slippage.
  4. Check that the water pump is working and that there are no leaks.
  5. Listen for any unusual noises coming from the engine. If you hear a squealing or ticking noise, it can indicate a loose or worn belt.
  6. If you have access to a timing light, you can use it to check the engine’s timing. If the timing is off, it could indicate that the belt is worn or damaged.

By following these steps, you should be able to diagnose a faulty timing belt and take the necessary steps to repair or replace it.


You can diagnose a faulty timing belt by visually inspecting it, checking for cracks, rips, and fraying, listening for strange noises, and checking for oil leaks.

Battery Draining: Why Does It Happen?

As you already know, your vehicle’s alternator is responsible for charging the battery. Additionally, you know that a faulty serpentine belt can negatively affect the alternator and battery. However, you should also be aware of other causes of battery drain.

Reason 1: Defective Alternator

The alternator may be defective if all other components, such as the power steering and the AC compressor, work fine. In that case, you need to diagnose the alternator. The alternator may have damaged diodes, overload, fluid leaks, or faulty jumper cables.

Here’s a video to watch on how to diagnose a faulty alternator on your vehicle.

Reason 2: Faulty Charging

Another reason for battery drain in your vehicle is when your alternator fails to charge the battery properly. It can happen due to bad or worn-out pulleys, misalignment, faulty wirings, bad or damaged alternator belts, and a blown fuse.

Reason 3: Parasitic Drain

The parasitic drain occurs when a vehicle isn’t running or is shut down for a long time. It is caused by electrical components that remain on and draw power even when the vehicle is not in use. Alarm systems, radio memory, interior and exterior lights, power windows, and heated seats are among the components that cause parasitic drains.

Parasitic drain can reduce the life of a battery, as the battery is slowly drained even when the vehicle is not in use. To prevent parasitic drain, it is recommended to disconnect the battery when the vehicle is not in use for an extended period of time.

Watch this video to learn how to diagnose parasitic battery drain on your vehicle.

Reason 4: Too Many Short Drives

The engine consumes a lot of power when it starts. As a result, the alternator needs a lot of time to charge the battery. For an engine to start, a car usually draws between 100 and 300 amps and a normal 12V car battery can deliver 600 to 1000 amps.

In general, an alternator takes around 30 minutes to 1 hour to fully charge a battery and compensate for the charge it draws during startup. For instance, if you have your 65 amp alternator and a 70Ah battery, the alternator will take 70/65= 1.0 hours to fully charge the battery. 

If your take short drives less than this time the battery health may deteriorate over time. To maximize the lifespan of your car battery, it is best to take your vehicle on a long drive few times a month. This will extend the battery life and its functionality.

Reason 5: Corroded Battery Terminal

Most car batteries are designed to last three to five years, but corrosion on a battery terminal can significantly reduce the lifespan of your battery. Corroded battery terminals can lead to battery drain or failure, leaving you stranded if the battery dies.

To avoid battery failure due to corrosion, regularly check the battery terminals for signs of corrosion. You can remove corrosion by brushing them using vinegar or baking soda at home (1). Additionally, if the battery no longer holds a charge, it should be replaced.


Five main reasons for your vehicle’s battery drain are faulty alternators, faulty charging processes, parasitic drain, short drive, and corroded battery terminals.
Battery Draining: Why Does It Happen? Infographic

How to Prevent the Timing Belt from Draining Battery?

Here are a few steps to ensure that your timing belt does not drain your battery:

  1. Check the belt’s tension regularly. A loose belt can cause the engine to run inefficiently, resulting in a drain on the battery. Worth noting, you can reuse the timing belt tensioner if you want to.
  2. Make sure the timing belt is properly lubricated. This will help reduce friction and make the belt run more smoothly and efficiently.
  3. Inspect the belt for any signs of wear and tear. If the belt shows signs of wear, it should be replaced as soon as possible.
  4. Keep the engine clean and free of dirt and grime. A dirty engine can cause the belt to wear out more quickly.
  5. Ensure the timing belt tensioners are properly adjusted. A tensioner that is too tight or too loose can cause the belt to slip, affecting the battery charging.

By following these steps, you can ensure that your timing belt does not cause your battery to drain.

Alternatively, you can replace your vehicle’s faulty or damaged timing belt/serpentine belt with the help of an expert. Make sure to follow the instructions in the owner’s manual if you intend to do it yourself.

The replacement procedure is different from manufacturer to manufacturer. Here’s a video you can watch to have a general idea of the replacement process. 


Check the belt’s tension regularly, inspect signs for wear and tear, clean the engine from debris, and ensure the timing belt tensioners are properly adjusted. Alternatively, you can replace the timing belt with the help of a mechanic.


What Is Draining My Car Battery When It’s Off?

Corroded terminals can cause a weak connection and drain the battery over time. So, make sure the battery terminals are clean and corrosion-free. Electrical glitches like faulty fuses and incorrect wiring can drain your battery when your car is off.

How Much Does Starting A Car Drain The Battery?

Starting a car may draw between 100 to 300 amps, while idling for 15 minutes will draw 3 to 4 amps. The charge will gradually decrease each time it is started and left idle. Midsize cars require 200 amps or less, while large cars may require up to 1000 amps.(2)

Can a Starter Motor Drain Your Battery?

Yes, they can. Failing or malfunctioning starter motors can drain the battery, resulting in a dead battery. How much power your vehicle’s starter motor will need depends on the engine type and horsepower. The motor will fail to start in case of insufficient power. 


You’ve reached the end of the article. Thank you for your patience. That was all about your query can timing belt drain battery. You should now be able to diagnose the timing belt problems and take the necessary steps.

Bye for now. Good luck.

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Aaron Byrne

Hi, Aaron Byrne here. I'm an expert automotive mechanic with 10 years of experience. I work on engine parts especially timing belts for their repair, maintenance, and replacement.

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.