How to Choose Good Quality Jumper Cables
Are you considering buying jumper cables or booster cables for a friend or relative? Do you need cables for yourself? Buy only good quality cables that can be trusted to do the job they were designed to do.
Remember that good jumper cables work and bad jumper cables might not work.
Are you considering buying jumper cables or booster cables for a friend or relative? Do you need cables for yourself? Buy only good quality cables that can be trusted to do the job they were designed to do. Remember that good jumper cables work and bad jumper cables might not work.
Jumper cable quality can be judged on these four parameters:
- Conductor gauge and material – 4 gauge or larger copper
- Clamp stiffness and grip strength – Low clamp distortion and strong spring grip
- Cable to clamp connection quality – To make a secure electrical connection
- Polarity identification – Color identifiers that stay in place
Conductor gauge and material
Choose cables with 4-gauge or larger diameter (i.e. up to 0-gauge) conductors. Note that gauge numbers reduce as diameter increases. Cables with 8-gauge or smaller (high number) conductors tend to overheat when amperage draw is high during jump-starting. Conductor material should be fine strand copper and not aluminum. Copper wire has less resistance than aluminum wire. Small strand cable has less resistance for the same gauge than coarse gauge cable because more conductor material is used. How can you tell the difference? Look inside the clamp at the bare wire. Copper wire is copper-colored; almost a red color. Aluminum wire is silver-colored. Aluminum wire conductors will usually have coarse strand with only a few large diameter wires in the conductor cable. When coarse strand cables are bent, the cable will tend to stay bent. Fine strand cables have many strands of wire in the conductor, are more flexible and resist staying bent. Arc welding cables are often used to make jumper cables because of their heavy gauge, fine wire copper conductors and thick yet flexible insulation material. The least expensive cables use stiff small gauge aluminum wire of about four strands with thin and stiff plastic insulation. Quality cables will have flexible large gauge copper wire with very fine multiple strands and rubber-like insulation.
Clamp stiffness and grip strength
Cable clamps should be made of a heavy gauge metal that does not distort as the clamp is opened and attached to the battery post. The opposing jaws of the clamp must stay parallel as they close. Strong springs are required so that clamping force is enough to pierce through the lead oxide coating that is on the outside of most battery cable clamps. If the lead oxide coating is not penetrated as the cable clamps are attached, an electrical connection is not secured.
Cable to clamp connection quality
This is the most ignored cable quality parameter. Cheap cables rely on a bare wire conductor being folded over and attached to the clamp with the cable in a crimp connection (See Figure 1). This connection may expose only a few strands of the conductor to the clamp and creates a high resistance connection. Corrosion, especially with aluminum conductors against stamped steel clamps, will create further resistance. Such cables might work intermittently or not at all. Quality cables often use a lug that connects all conductor strands together and is mechanically attached to the cable clamp (See Figure 2). The cables in Figure 2 have functioned perfectly for thirty-three years.
Cables should be labeled for polarity with RED on the positive (+) cable clamp and BLACK on the negative (-) cable clamp. Cheap cables may have slip-on clamp handle covers that easily fall off. This may result in polarity confusion when the cables are used. Polarity confusion can cause battery explosions, vehicle electronic component damage, and failure to start the disabled vehicle. Quality clamps often used molded-in-place clamp covers that cannot be easily removed.
Remember and apply these four judgment parameters when shopping for jumper cables.