We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What are Jumper Cables?

Michael Pollick
By
Updated May 23, 2024
Our promise to you
WikiMotors is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WikiMotors, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A car's battery is designed to perform one task very well, and that is to power an electric starter motor whenever the ignition switch is turned on. Once a car starts, an electric generator called an alternator assumes responsibility for most of the car's electrical needs, including recharging the battery for future starts. If the battery's power level becomes too low to turn the starter motor, the driver may have to use a second battery to provide additional power. The cables used to connect the auxiliary battery to the dead battery are called jumper cables, because they allow electrical power to "jump" from one battery to another.

Jumper cables are insulated lengths of heavy gauge wire which have large spring-loaded alligator clips on either end. Two clips are usually marked "positive" with the use of red insulation and plus marks (+), while the other two clips have black insulation and "negative" marks (-). This is a very important designation, since the positive clamps on each end of the jumper cables should only be attached to the positive terminals of the batteries, and the negative clamps should only be attached to the negative post or grounded area of the engine block.

In order to use jumper cables safely, the two batteries need to be in close proximity to each other, which usually means maneuvering the second vehicle end-to-end or side-by-side with the vehicle containing the dead battery. Jumper cables can be 10 feet or more in length, but the clamps need to be seated securely on the battery posts in order to get the best connection. Once the batteries are positioned properly, the driver can begin to attach the jumper cables to both vehicles.

Jumper cables essentially draw the power from one battery and feed it steadily to a uncharged battery. The driver should take one positive clamp and attach it securely to the positive post of the "good" battery. The corresponding positive clamp should then be attached to the "bad" battery. The negative clamp on the same end of the jumper cables as the first positive clamp should then be attached to the negative post of the "good" battery. At this point the remaining negative clamp should never come in contact with the positive clamps, since it would complete a circuit and create sparks. The last negative clamp should be attached to a piece of metal connected to the engine block but away from the battery to avoid creating sparks.

Now that the jumper cables have been properly attached, one driver can start the "good" car, which sends power from both the alternator and battery through the jumper cables and into the "bad" battery. This recharging process can take several minutes, since car batteries use a chemical process to generate their power. After a certain amount of time has elapsed, a driver can then attempt to start the "bad" car by turning the ignition. If the battery has regained enough power or the power from the second battery is sufficient, the engine should turn over and the alternator should begin charging the battery again. If this doesn't happen on the first attempt, the battery may need more time to build up a charge.

Once the car has started, the jumper cables should be removed in reversed order. The negative clamp on the "bad" car should be removed first, then the negative clamp on the "good" car. The positive clamp on the "bad" car is removed next, followed by the positive clamp on the "good" car. The jumped car's engine should be allowed to idle for several minutes in order to make sure the battery has been charged enough to handle a second start if necessary. Many drivers who have their cars jump started will leave the engine running until they have reached their destination or a repair shop.

Jumper cables are relatively inexpensive and should be stored in a car's trunk for emergency use. If a car breaks down on an isolated stretch of highway, having a set of jumper cables can make the difference between a quick jump start and a long wait for a wrecker or tow truck.

WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Pollick
By Michael Pollick
As a frequent contributor to WikiMotors, Michael Pollick uses his passion for research and writing to cover a wide range of topics. His curiosity drives him to study subjects in-depth, resulting in informative and engaging articles. Prior to becoming a professional writer, Michael honed his skills as an English tutor, poet, voice-over artist, and DJ.
Discussion Comments
By Ruggercat68 — On Oct 21, 2014

I try to encourage everyone I know to invest in the best heavy duty jumper cables they can afford. I can't tell you how many times I've stopped to help a stranded motorist and they'll hand me the flimsiest set of bargain basement battery jumper cables available. If those car jumper cables look too bad, I'll gladly go back to my truck and get the good ones.

I think any driver who plans on going on a long trip needs to know how to use jumper cables. A weak battery may be the least of their problems on the highway, but at least they'll know what to do if someone else volunteers to help with a jump start. I've seen people get the positive and negative clamps mixed up, and that can really mess up both cars in a hurry. I also warn people not to connect the last negative clamp to the battery post itself. It's safer to use a different metal piece as a ground in case there is a spark.

By RocketLanch8 — On Oct 21, 2014

I try to keep a set of jumper cables in the trunk of any car I'm driving, but I don't always get the heavy duty kind. I have been asked to help jump start more stranded cars than I can remember. For whatever reason, people around here tend to forget when they turn their headlights on during the day, like when it rains. Other people have loose battery connections and only think they need their car jumped off.

Michael Pollick
Michael Pollick
As a frequent contributor to WikiMotors, Michael Pollick uses his passion for research and writing to cover a wide range...
Learn more
WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.