5 Reasons Why Jumper Cables Melted


Most drivers know that it’s possible to jump-start a dead car battery by connecting it to another vehicle’s battery with jumper cables. But what happens when those jumper cables suddenly get too hot and melt? What could cause this, and how can it be avoided?

While there are 5 reasons why your jumper cables melted, the most common culprit is misaligned cable connection. Let’s take a closer look at what this means, as well as the other 4 possibilities.

Reason #1: Misaligned Connection

The single most common reason for melted jumper cables is a misaligned connection. When connecting jumper cables from one car battery to the other, you must make sure that the cable’s clamps are connected to the corresponding terminals on the battery.

Typically, the red cable clamps attach to the positive post, while the black cable should clamp to the negative post. If these are reversed, it will lead to electrical failure and cause the cables to melt.

Today’s cars have safety precautions that keep the battery from exploding, frying the jumpers cables instead. To ensure that this doesn’t happen, it’s best that you don’t rely on color alone.

Look for the “Plus” and “Minus” symbols and match them up accordingly. If you’re using a quality set of jumper cables, you should get a relatively fast charge.

If you’re using cheap cables, however, it can take a lot longer to charge your battery, among other issues. This brings us to the next common reason.

Reason #2: Poor Jumper Cables

Jump-starting a vehicle by connecting its battery to a good, working battery is a pretty straightforward task if the proper components are used and the correct steps are followed.

However, using jumper cables that don’t meet a certain standard will likely lead to trouble. From not being able to get the electrical current needed to complete the job to melted cables, it pays to invest in quality equipment.

What Does Gauge Mean?

The gauge refers to the thickness of the wire. Gauges are often used to rate the total amperage load and metallic composition of the jumper cables. The lower the gauge rating the more “heavy-duty” your jumper cables are.

If you go to any reputable mechanic shop, you will likely find them using 0-gauge jumper cables. This is the golden standard that delivers the best performance but at a hefty price, sometimes reaching as big as 300$.

That high of a gauge rating is not recommended for regular drivers, so your better off with a 4-6 gauge rating. But if your buying cheaply made jumpers cables in the hopes of saving a few bucks, this is where the problem arises. While they certainly look nice and new in their packaging, they simply don’t perform well.

This is because those subpar cables you picked up for $15 less are actually made with a gauge that can’t handle the flow of electricity. Often somewhere in the 10-gauge range, these cables can’t adequately jump vehicles and should be used only in emergency situations.

You can usually get away with using 6-gauge, but anything beyond this will put you at risk of failure. Not only will your vehicle’s battery not be able to receive the charge it needs to jump your car, but it will likely cause the jumper cables to melt.

Whether you are gifting a roadside emergency kit to someone or you need good jumper cables for yourself, spend a few extra dollars and pick up a high-quality 4-gauge set of cables.

Reason #3: Improper Material

Another common problem that drivers run into is the material used in the jumper cables. Aluminum is now being used in many cheap jumper cables in an attempt to cut production costs and make the manufacturer more money.

Unfortunately, this is just another example of the consumer being the one who suffers the consequences. From poor current to melted cables, it is unlikely that aluminum jumper cables will deliver the outcome you want.

What Are The Best Material For Jumper Cables?

For the best results, stick with cables that use copper in their construction. Copper is an excellent conductor of electricity, especially when it is a thicker gauge.

Now, with that being said, a combination of aluminum and copper works well, too. What’s more, it’s an effective way to reduce costs for both the manufacturer and consumer.

These types of jumper cables use an aluminum cable that is copper-clad, giving you conductivity that is very close to copper but at a lower price and weight.

For the budget-minded, these types of cables make a solid investment while providing acceptable performance.

Reason #4: Damaged Cables

Proper storage is very important and contributes to the performance of jumper cables. To ensure that your cables continue to function correctly, you need to take the time to safely store them when they’re not being used.

What Damages Jumper Cables?

Storing your cables where they are susceptible to extreme temperatures can cause physical damage that affects their performance. High heat, for example, will eventually cause the cables to crack and split.

The insulation that surrounds the copper needs to be kept in an optimal condition at all times. If there are compromises in the insulation, the copper can become damaged.

When this happens, hooking up the cables to a battery can result in dangerous electrical currents that melt the line.

You also want to do everything you can to keep moisture away from the cables. If your jumper cables are subject to water, it can reduce their ability to conduct electricity, thereby limiting their effectiveness adequately.

As such, you should consider investing in jumper cables that come with a storage bag or simply purchase a quality container to store them in when not in use.

Reason #5: Loose Connection

Even though you have correctly connected the jumper cables to the batteries, a loose connection can quickly lead to overheating.

There is a large amount of electrical current trying to travel from one battery to the other. So whenever a connection isn’t snug and made complete, that electricity causes the cables to become exceedingly hot, thus melting the line.

What Causes a Loose Jumper Cable Connection

Mostly, loose jumper cables are caused by human error. But it can also be caused by corrosion, dirt, etc, on the jumper cables or the battery terminals.

Always make sure that the cables have excellent contact with the battery terminals. Inspect the clamps to ensure that they are capable of attaching firmly in place.

If the clamps are of low quality, consider investing in a new set of jumper cables. It’s better to play it safe and use new cables instead of risking further damage or injury.

What to Look for in Jumper Cables

When you go to pick out a good set of jumper cables, there are some factors you want to consider. We’ve pointed out most of these throughout this guide, but let’s go over them in detail so that you invest in quality cables.


The rating of jumper cables refers to the gauge of the wiring used in the construction of the cable. The wiring is what is underneath the outer insulation, which serves to keep your cables protected from the elements.

In the context of jumper cables, higher gauges don’t mean better. In fact, it’s quite the opposite. As such, you want to stick with cables that have a lower gauge number.

You will get the best results by using 1- or 2-gauge cables, as opposed to 8- or 10-gauge. The lower the gauge, the thicker and more robust your jumper cables will be.

Many cables that are rated for emergency use are often in the 4- to 6-gauge range. And as we mentioned earlier, professional mechanics usually rely on 00-gauge jumper cables because they offer the best performance.


Cheaper jumper cables are typically very flimsy due to the minimal insulation used to protect the internal copper or aluminum wiring.

The same applies to the clamps and the sheathing around them. You want to buy jumper cables that are thick and sturdy. Not only will this go a long way in ensuring their longevity, but it will also enhance the performance of the cables.

The harder it is to bend the cables, the better quality of the insulation. Spend the extra money and invest in a durable, long-lasting set of cables to ensure the best form and function.


The shorter your jumper cables are, the more challenging it will be to jump your vehicle successfully. For the most part, 10-foot jumper cables should serve you well.

But you never know what kind of scenario you will be in when you need a jump. If you are parked a certain way when your battery dies, a 10-foot cable may not be long enough to get a jump from another vehicle.

As such, you may want to spring for the extra cost and invest in 25-foot jumper cables. They are going to be a bit pricier, but you’ll have peace of mind knowing that you can get a jump in just about any situation.


The style of your jumper cables’ clamps can make the difference between getting a secure, snug connection and a loose one. Clamps that feature pronounced alligator teeth will provide the best “bite,” ensuring that you can safely and effectively attach to the battery’s posts.

Better teeth also allow you to clamp down in various positions, which can come in mighty handy depending on the battery posts’ location and accessibility.

More often than not, you will find suitable clamps on high-quality jumper cables, whereas the lesser brands use cheap, ineffective clamps.

If you currently own a set of jumper cables but aren’t getting good results from them, take the time to closely examine their clamps.

You may find that they are the problem. If so, consider investing in a new set that has the style of clamps outlined above.


Of all the metals, solid copper is often seen as one of the most effective conductors of electricity. When it comes to jumping automobile batteries, excellent conduction is everything.

Without a solid connection for the electricity to pass through, you aren’t going to get the jump needed to successfully charge your battery.

The same applies to the metal used in your jumper cables. Inadequate metal will make it very difficult to jump your battery in a timely manner.

Not only is it likely that it will take longer than necessary to successfully jump your vehicle, but you risk damaging the cables, as well.

To ensure that you get the best results, try to avoid aluminum jumper cables and stick with copper. This metal is tried and true and will provide you with the best performance and reliability.

If you’re on a tight budget and trying to save as much money as you can, copper-clad aluminum jumper cables should do nicely. Although they may not be as sturdy as copper cables, they should deliver the conduction needed for a successful jump.


Now that you know the main reasons that cause jumper cables to melt, you can proactively avoid them when you need to jump your battery. What’s more, you will have a much easier time finding quality cables to invest in.

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