Two Things to Double-Check When Choosing Battery Cables – and More

Posted on Sep 25, 2020 by Robert Iversrud

The battery cable is among the most important components in a battery management system. High quality battery cables will help ensure you have power and avoid battery drain—but only if they are properly sized, installed and maintained.

There are two things you must absolutely double-check when selecting your battery cables.

Gauge

A battery cable with the wrong gauge is one of the most common issues in improper installations and Terminals_Heat_Shrink can pose a much greater risk than some realize. A wire gauge that is too thick can prevent proper current distribution. An overly thin wire gauge can short-circuit and, in extreme cases, cause the engine compartment to start on fire. To avoid such issues, ensure that amp and gauge charts are made available to all involved in the selection process. Here are some easy, comprehensive charts you can refer to:

Battery_Cable_Load_Charts_blog_stacked (002)

Length

Another key factor is wire length. When choosing the length you must take into consideration the voltage drop, or the amount of voltage lost over the length of the automotive wire or cable. As the wire length gets longer, electrical resistance builds up until it forces the voltage down below a usable level. Voltage drop can be calculated using Ohm’s Law: Voltage Drop = Current in Amperes x Resistance in Ohms.

Higher gauge (thinner) wires will have a higher drop rate than shorter wires of a smaller gauge (thicker wires) because the resistance of a wire is based on its cross-sectional area over a distance.

For example, for a 12-volt DC system, if your load current is 10 amps and your distance of cable is 20 feet, your voltage drop would be 1.0% or 11.8 volts at the end of your cable run using a 4-gauge battery cable. Using wire size calculators or our wire gauge charts above can make it easier to determine voltage drop.

In summary, take the time to make sure you are selecting the right wire gauge and length for your battery cable – it will pay dividends in the long haul.

Other things to keep in mind

Another important factor in choosing battery cables is strand count. Stranded conductors are composed of multiple metal strands bunched together in any number of configurations. They are much more flexible than solid conductors. As a rule of thumb, the higher the strand count, the more flexible the cable will be.

Also consider the outer jacket used in the cable. The PVC and XLPE materials commonly used for battery cable insulations are excellent for tight battery applications, since they are stiffer than EPDM and neoprene rubber jackets. Additional details:

PVC (vinyl) provides controlled oxygen and water vapor transmission, UV stability, and is cold resistant, light weight and affordable

XLPE (crosslinked polyethylene) offers high chemical resistance and moisture resistance, and is good for high temperature/high voltage applications

EPDM (rubber) offers excellent resistance to environmental factors such as ozone, UV, and general weathering

Finally, keep safety ratings in mind. All battery cable options offered by Waytek meet SAE J-1127, Ford and Chrysler specifications for use in automotive applications. In addition, SGR battery cable also meets UL-558 and UL-553 flame resistant standards.

Installation and maintenance

Once you’ve chosen the battery cable with the right specs for your application, make sure to connect it securely to the battery terminal. A faulty connection can compromise the performance of a battery system and is the leading cause of most battery terminal post meltdowns. By sizing the correct cable, using properly assembled cable connectors, and practicing good maintenance habits, you will minimize the potential for problems.

Maintenance is simple yet too often neglected: To avoid corroded terminals, periodically inspect the battery cables to make sure they haven’t cracked over time. Also be sure to keep your battery posts clean and to remove any dirt from the top of the battery. Make sure your lugs are tightly secured to the battery posts and that your vent caps are in place.

By following these guidelines, you can guard against faulty connections that can reduce performance in a battery system.

If you have additional questions about selecting the right battery cable for your installation, please contact us; whether you’re looking for battery cables, battery boots or disconnect switches, Waytek is ready to meet your battery management needs.

Explore Waytek’s extensive offering of high-quality battery cables below:

SGR battery cables - Rubber insulated and typically used in automotive applications, but their properties make them suitable for other industries as well.