Major Reasons Why Your Jumper Cables Melted

Picture this: you’re about to jump in the car and head off to work when you discover the car won’t start. You’re stressed, running late, and quickly realize that your car won’t start because of its battery. 

You decide to use your jumper cables and the car moving, only to discover that they have melted. 

In this guide, I’ll walk you through five major reasons your jumper cables might have melted. I’m a seasoned auto expert with a few years of experience, and I can help you solve this problem! Let’s dive right in.

What Are the Reasons for Your Jumper Cables Melting? 

Your jumper cables could melt for several different reasons.

Confusing Positive and Negative Terminals

The mistake of confusing the positive and negative terminals is one of the most common. If your jumper cables aren’t hooked up right, your battery could catch fire or explode, which would be very dangerous for anyone in the car or nearby. Even though your car has some fuses to protect itself against an electrical short, it’s important to note that they may not be enough. A mismatched connection could lead to the early failure of a vital component like your alternator.  

The Use of Thin Jumper Cables

When you want to use jumper cables, you have to check the power of your battery and the current that your jumper cables can handle. You can find this information on the battery and the packaging of the jumper cables. If the jumper cables are not big enough, there is a high chance that they will melt due to excessive heat.

Low-Quality Jumper Cables

The quality of your jumper cables is, of course, important. If you use poor-quality cables surrounded by a case that is too thin, it may not withstand the heat and melt. Jumper cables are often a long-term acquisition, so there is no reason to invest in a poor-quality product. 

Jumper Cables With Too-small or Too-big clamps

We don’t think about it directly, but the clamps’ size is as crucial as the quality of the jumper cables. If you buy jumper cables with clamps that are too small or even too big, they may come loose. And loose jumper cables cause many other problems. With the force of the spring that holds them closed, they can be thrown out and land on the opposite terminal. This will create a short circuit, and as a result, your jumper cables will melt.

Jumper Cables are Too Old

You may have jumper cables in your garage that are a few years old. Like with any object, time affects jumper cables, especially in a garage. It can be wet, hot, cold, and so on. The plastic surrounding your jumper cables suffers and degrades, or some parts of the clamps can rust if your cables are not of good quality. For these reasons, it is important to check them before using them. If you don’t do this, you risk an accident that can cause your jumper cables to melt.

In the following sections, we’ll discuss the five most common mistakes when people use jumper cables and the best ways to avoid them.

How to Prevent Your Jumper Cables from Melting?

How to Prevent Your Jumper Cables from Melting

Here are some important things to remember to prevent your jumper cables from melting:

Connect the Jumper Cables to the Battery Correctly.  

All that’s required to connect the jumper cables is that the red ends go to the red positive terminal and the black ends go to the black negative terminal. If there’s a faulty connection, the car battery can catch fire or explode, leading to vehicle damage and possible injury. Following the steps below will guarantee a correct connection is established:

  • Place the functioning vehicle in front of the malfunctioning vehicle so their hoods are parallel and close enough.
  • To find the two batteries, you’ll need to pop the hoods of both cars.
  • Take the covers off the batteries so you can see the positive and negative terminals.
  • Get started by attaching one red clamp to the car battery’s positive metal terminal. The metal terminal of the positive terminal of the running car should be connected to the other end of the same red clamp. 
  • You should then connect the other black clamp to the metal terminal of the disabled vehicle after connecting one of the black clamps to the functioning vehicle’s negative terminal.
  • While applying the brakes, place the car in neutral. Start the engine of the functioning vehicle, then let it run for a while. Occasionally, you might accelerate a little to give more power to the battery. The dead battery will begin to recharge slowly during this time.
  • Attempt to restart the broken-down car. If it still does not start, turn off the engine and double-check the connections between the cables and terminals before restarting the vehicle. You’ll need to replace the battery if it doesn’t turn on after five minutes.
  • If the car starts, your battery has partially recharged, but you are not done. 
  • Next, detach the black clamp and the other black clamp to remove the jumper cables.
  • Make a similar move with the red clamp.
  • Reinstall the caps over the battery terminals.

Avoid Creating Sparks.

Be careful when charging a lead-acid battery because the chemical reaction creates hydrogen, a highly flammable gas. You can reduce the risk of an explosion by not allowing the clamps to make sparks when connecting the jumper cables and by keeping any ignition sources away from the cables.

Do Not Lean Over the Battery When Using Jumper Cables.

Thick Jumper Cables

Some danger is always present when attempting a jump start. Stay away from the battery because a sudden overflow of acid could happen due to heat, pressure, or a short circuit inside the battery. 

Choose a Jumper Cable of Sufficient Thickness.

The jumper cable must supply enough power to the dead battery. If the cables aren’t thick enough, they won’t carry enough current, and they’ll heat up, and you risk your jumper cables melting. Therefore, you must refrain from counting on the person assisting you to have the proper cable. To avoid risking your safety, you should invest in your jumper cables and not buy cheap ones. 

Store Cables in a Way that Does Not Damage Them.

Jumper cables are used to transfer electricity from one vehicle to another. If there is corrosion inside the cables, it can increase their temperature and lead to a fire. Therefore, maintaining functional jumper cables is essential. You can achieve this by keeping them in a bag and putting them somewhere dry, out of the reach of moisture. The better sets of cables will come with a plastic cover. 

What to Look For to Get Good Quality Jumper Cables?

Whether a vehicle has a diesel or gasoline engine will determine the type of jumper cables to use. You should consider the following details on the battery to choose the appropriate jumper cables for your vehicle:

  • the voltage expressed in volts (V)
  • the intensity expressed in amperes (A)
  • the charge capacity in amperes per hour (A/h).

You can choose the best jumper cables by carefully considering the following criteria:

Choose Heavy-duty Clamps.

No matter what cables you choose, ensure that you buy cables with strong clamps that can securely connect to a battery with top or side terminals. If you buy good-quality clamps, they should be able to make a solid connection to a reliable ground source under the hood, such as a bolt on the engine block. 

Car Engine

Low-quality clamps make contact with the lug only at the cutting edge of the jaws, while bronze or shell clamps will embrace the lug at a broader base. It’s easier for electricity to flow when there’s more surface area for it to make contact with. 

Cable Length

The cable length is a crucial factor to consider. Make sure you purchase jumper cables at least 20-25 feet long, especially if your car is large or needs to charge from the back. 

Insulation of Jumper Cables

Heavy-duty cables should have thick insulation. It would be best to buy cables with thicker insulation to limit the heat the cables produce. When placed side by side, the cables may give the impression of being of the same heavy gauge. 

However, a thinner gauge wire encased in a thicker insulation jacket may be the tradeoff for a lower price. Make sure the gauge is stated on the package at all times. 


Strong Jumper Cables
Tools Safety Tools Extension Cords Jumper Cables

It would be best to consider the amperage of your future cable as one of the criteria. If you drive a large vehicle, this is very important. To charge a vehicle with a 4.5-liter engine, you’ll need a cable with at least 700 amps of current. A high-powered V8 or more requires a high-amperage cable capable of handling at least 1500 amps.

You should exercise caution because diesel vehicle batteries are more potent than gasoline batteries. Pick out the stronger cable from both in this situation. I recommend always using larger-than-needed jumper cables. For gas-powered vehicles, I recommend A 4-gauge or 6-gauge set of jumper cables that will be enough for most vehicles.

Wire Size and Thickness

As the name implies, wire size refers to the diameter of the wires. The best way to get your car started is with thick, sturdy wires that can withstand the high currents required during starting. Weak, low-cost cables make it difficult to draw sufficient current safely. 


What Causes Jumper Cables to Overheat? 

Several factors can cause your jumper cables to overheat. These include a bad connection, too thin cables, or poor quality jumper cables. Therefore, it’s essential to pay close attention to all the criteria we mentioned in this article.

Is it Dangerous to Jump-start a Car? 

It is safe to use jumper cables if your battery is dead. There are some steps to follow when using them to avoid dangerous mistakes. Also, avoid leaning over the battery when using jumper cables; you never know what might happen or why the battery is suddenly dead.

Can You Still Use Melted Jumper Cables?

No, melted jumper cables are not to be used anymore. You risk a severe accident and damage to your vehicle or its electronic parts. High-quality jumper cables adapted to your car are the best way to avoid problems.


As you may have guessed, jumper cables are essential accessories that you should purchase with a lot of thought in mind. There are several steps to follow when using them, whether during their use or purchase. Depending on your vehicle, you should also pay attention to the specific battery specs when buying them. 

Pro Tip: Be sure to get jumper cables before you have a dead battery, and don’t use someone else’s because you may not have all the needed information about them. At this point, we often want to rush because it always occurs at the wrong time. 

Take the time to choose and store them well in your vehicle. This will give you peace of mind; if this happens to you, you will be prepared and lose less time. You may incur high costs if problems occur while using cheap and not well-made jumper cables. This is especially the case if a vehicle component is damaged and you must have your vehicle towed. It’s typically the situation anyone with common sense would want to avoid.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top