Question: My bestie needed a jump so I went over to their house and we connected the cables. But I noticed they were getting really hot, so we stopped and I disconnected them. I want to know why jumper cables get hot, will it start melting and smoking? What happens if we put jumper cables on the wrong terminals?
Answer:
We’re glad you acted quickly and disconnected the jumper cables before they melted! Yes, jumper cables getting excessively hot is a major concern.
When using your jumper cables correctly, they will get warm. If they are too hot to handle or you notice signs of melting or smoking, be sure to disconnect immediately.
Why are my jumper cables getting hot?
There are a few different potential causes for jumper cables getting hot, melting or even smoking:
- Connecting the cables to the wrong terminals: The red cable should connect to the positive terminal and the black one to the negative terminal. Make sure they’re set up properly to avoid damage to the cables or the cars.
- Poor or loose connections to terminals: Ensure the cables are firmly and properly attached to the battery terminals to handle these high volumes of electricity transfer.
- Low-quality jumpers can heat up and burn out: The reason why high-quality jumper cables are made of copper and thick gauge wire is to reduce this unwanted heat byproduct. Some manufacturers use aluminum to reduce costs, but these cheaper cables are prone to overheating and don’t always transfer the current.
- Damaged jumper cables: Always visibly inspect the cables and their connectors to ensure they aren’t physically damaged or frayed.
- Jumper cables are too thin: Using cables that are too thin for your car will cause the cables to get hot because the car’s battery is too powerful. You can use a thicker gauge cable, even on a smaller car, without worry. Jumper cables are measured in American Wire Gauge (AWG), and a lower number represents a thicker cable that can handle more power.
- Excessive cranking: If you attempt to crank the engine for too long, the cables will get too hot. If this happens, give them a few minutes to cool off before trying again.
- Possible short circuit: You can short circuit your car if any part of the cables are touching each other or if you clip both ends of the cables to the same piece of metal. Not only will this cause them to overheat quickly, but you can damage your battery or start a fire.
How to prevent jumper cables from getting hot
A high-quality jumper cable with a low AWG can save you from damaging your car (or hurting yourself) when jumping a car. Additionally, take the time to check that your jumper cables are connected correctly and securely and that the metal clips are not touching.
If you need a jump but realize your cables are damaged or are too small, it is better to call for roadside assistance.
Xuyun Zeng is a content strategist with a wide-ranging content background including tech, journalism, cars and health care. After graduating with highest honors in journalism, Xuyun led a newspaper to win eight awards, helped start an award-winning film industry podcast and has written over a hundred articles about cars repair, state laws and insurance. Prior to joining Jerry, Xuyun worked as a freelance SEO consultant with a mission to create the best content that will help readers and grow organic traffic.
Ashley Eneriz is an editor and finance writer with over 15 years of experience in a wide range of financial topics, including car loans and insurance. In editing for Jerry, Ashley aims to make all car material reader-friendly for both the new driver and car enthusiast alike. Prior to joining Jerry, Ashley was the financial deputy editor for ConsumerAffairs. Her work is featured on Forbes, Yahoo, MSN, The Hartford and more.
