Cable & Automotive Wires

Why choose Home of 12 Volt Online for your 12 Volt cable? 

Why choose 12 volt automotive cable? What is the difference between 12 volt automotive cable and 240 volt cable? 

It is not commonly known that there is a big difference between the 240 volt household electrical cable and 12 volt automotive wire. The two types of cable are definitely not the same, and as a result, they will offer a very big difference in performance of your system when using one verses the other. 

12 Volt cable is manufactured with many thin strands of copper wire, bundled together in sheathing for protection. As the voltage of automotive installations is low compared to household electrical power, (9~48 Volts compared to 110 ~ 260 Volts), it is vital to use a cable that allows for as much power to be harnessed whilst minimizing voltage drop. 

The use of many thin wires in automotive cable allows for the low voltage to easily be carried through the cable whist minimizing resistance. 

240 Volt cable on the other hand contains less, thicker strands of copper compared to 12 volt cable. As the voltage is higher in household electrical circuits, the voltage drop is less impacting and therefore the tolerance of voltage drop is much wider (see example below). The cable can therefore be thicker in 240 volt and less stands can be used, whilst still successfully transferring the required amperage. 

If 240 volt cable is used on 12 volt electrical systems, then the use of less, thicker strands of wire will result in an increase of resistance and ultimately a huge voltage drop will be the result. 

It is important to use good quality 12 volt automotive cable in any 12 volt installation to ensure the optimum running of your appliances is achieved. 

Home of 12 Volt stock only high quality Australian made 12 Volt automotive cable. 

Example of the difference in voltage drop between the voltages and why voltage drop is so important in low voltage systems: 

10% voltage drop on 240 volt = 216 Volts. At this voltage level, 99% of appliances will still run perfectly. 

10% voltage drop on 12.7 Volts = 11.4 volts. At this point you have reduced your battery from 100% down to only 30%

How do I know what size cable to choose for my installation? 

There are many things to consider when choosing the gauge of your 12 volt electrical wire. The most important considerations are outlined below: 

1. How long is the total length of cable?

The total distance of the cable run will play a vital role in the overall rating of the cable. The longer the length of cable = the increase in voltage drop. When running longer lengths of cable, it is a good practice to increase the gauge in order to minimize voltage drop.

2. What is the total load of all appliance(s) on the length of cable? 

There will be a big difference in the requirement of the cable if you are looking to run multiple appliances on the same 12 volt power cable, compared to only running a single load. It is therefore important to identify the overall power draw of all appliances that will be running on the same line and install a 12 volt power cable that will achieve this power draw. 

If you are only running a single appliance, then it is certainly easier to work out the power usage and choose a 12 volt battery cable that will suit. 

• Remember that it is important to ALWAYS fuse the 12 volt power cable as close to the battery as possible. Home of 12 Volt Online offer a huge selection of fuses to suit all types of 12 volt power installations.

3. Temperature

One of the key factors of 12 volt power cable is in fact temperature. Temperature will play a huge role on how efficient your 12 volt auto electrical cable will be. Home of 12 Volt offer a guidance sheet on each cable sheet to help guide you when choosing your 12 volt cable. 

4. Single core vs Twin Core cable 

The rating of 12 volt battery cable differs when using a single core vs a twin core cable.

For example: One of the most common gauge 12 volt battery cables is a 8B&S cable.

If installed in a single core cable, the 8B&S will have a efficiency factor of 1. Compared to a twin core cable, this same 8B&S cable will have a efficiency factor of 0.8. 

8mm / 8B&S cable has a rating of approx 74 Amps for single core (at 30degrees). This same cable in a twin core will have a rating of approx 59 Amps in the same condition. 

Do you need help in choosing the correct cable gauge? 

Home of 12 Volt Online are specialists in the field of 12 Volt automotive electrical cable. If you are unsure of what 12 volt cable suits your needs, then why not CONTACT US directly on 08 8391 3121