Jumper Cables: FAQs on Gauge, Length, and Clamps

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on April 15th, 2024

Reading Time: 5 minutes
Summary
  • A jumper cable’s gauge defines the thickness of the wires. This will be indicated by a gauge value ranging from 1 to 12.
  • A longer jumper cable will allow you to park the charging car in a more convenient location. A set of 10-foot jumper wires will only allow charging if the two vehicles are facing each other.
  • Good jumper cables have clamps that can securely fasten themselves onto the batteries. Otherwise, they can come loose and electrocute you.

Not all jumper cables are the same. They’re made with varying specifications and characteristics for different intended uses. Some of these characteristics include insulation, cable length, clamp type, and wire gauge.

What’s a Jumper Cable’s Gauge and Its Meaning?

Caution: Always use safety glasses when working around car batteries.

Using the appropriate jumper cable gauge ensures that your battery receives the power it requires to start. The gauge defines the thickness of the wires. This will be indicated by a gauge value ranging from 1 to 12.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Thicker cables have a lower gauge number unless you’re using the metric system for cables. Metric wire and cable numbers indicate the diameter of the wire or cable in millimeters rather than using gauge measurements.

Transferring larger voltages will require thicker wires. If you use thin wires to transfer large voltages, your vehicle might not receive enough voltage to startup properly. Additionally, wires can heat up when they transfer too much voltage. 

Copper cables are far better than aluminum cables. If you’re building your own set of jumper cables, welding lead works better than just about anything else because it’s made with a lot of small wires for flexibility.

Copper cables are far better than aluminum cables. If you’re building your own set of jumper cables, welding lead works better than just about anything else because it’s made with a lot of small wires for flexibility.

Richard McCuistian, ASE Certified Master Automobile Technician

Further, current travels on the outside of each wire and not through the center, so a lot of small wires will have more area than a few larger wires, which are also quite stiff. 

The longer the cable, the more expensive it is. Old welding lead works just as well if you can obtain some from a local welding shop. | Image Source: Richard McCuistian

As with gauge, thicker is the way to go in terms of insulation. Do note that thicker wires don’t necessarily have thicker insulation. 

Also, contrary to what you may see in movies, you won’t get electrocuted by a 12-volt battery with jumper cables, anyway. However, if the wire gets hot, you might get burned if you touch a bare cable that has been heated by current flow.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: For most people, the best gauge for jumper cables would be a 6-gauge or 4-gauge, but bigger is better. Moving up to a 0 gauge (like the cable in the photo) will perform better if good quality clamps are used along with it. But 6 or 4 gauge might be thick enough to handle the required voltages for most SUVs, cars, and vans without being too cumbersome and expensive.

If you have a vehicle with a large engine, such as a truck or RV, you should look for 2-gauge cables. Heavy-duty vehicles, such as semi trucks, might require cables with a gauge rating of 1.

How Long Should Jumper Cables Be?

Anyone who has ever had to jump-start a car understands how difficult it can be to align the two vehicles in order to connect the cables. A longer pair of cables will allow you to park the charging car in a more convenient location. When the cars are facing each other, a set of 10-foot jumper wires should suffice, although this isn’t always possible. If you want the charging car to park behind the stopped one, you’ll need at least 20 feet of wire. However, longer jumper cables will be more expensive, heavier, and hard to handle.

When the cars are facing each other, a set of 10-foot jumper wires should suffice, but if you want the charging car to park behind the stopped one, you’ll need at least 20 feet of wire.

Why Are Good Jumper Cable Clamps Important?

If you’re looking for jumper cables, make sure that the clamps are able to securely fasten themselves onto the batteries. Otherwise, they can come loose and electrocute you. This means they should have a strong spring that allows them to latch onto the battery’s terminals.

Alligator clamps are probably the best because they have teeth on their clamping surface that help keep them in place. The clamp handles should also have a thick layer of rubber to protect you from getting electrocuted and so you can securely grip them.

While these advantages might seem like marginal gains, they can all add up to improve your overall experience when it comes to jump-starting your vehicle.

Where to Get New Jumper Cables for Your Vehicle

A pair of high-quality jumper cables is a lifesaver when you’ve got a dead battery under the hood. The good news is that here at CarParts.com, it’s extremely easy to find the best jumper cables for your ride.

Start shopping by entering your vehicle’s year, make, and model into our vehicle selector. This will narrow down the catalog to compatible jumper cables for your car, truck, or SUV. You can also use the search filters to narrow down the results according to your preferred brand, price range, and more.

All our products passed stringent quality checks to ensure maximum durability and dependability. Never second-guess product quality when you shop from us.

Our jumper cables come with a low-price guarantee, so you don’t have to worry about going over budget for your vehicle’s needs. Order now, and we’ll deliver the part you need straight to your doorstep in as fast as two business days.

Can’t shop online? Don’t worry! You can also reach us via our toll-free hotline. Call us anytime, and our team of round-the-clock customer service representatives will be ready to assist you.

Check out our products today!

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician