Can I lengthen the cable between the solar controller and the solar panels?

RemotePro® Viewed: 81

Most of the Tycon RemotePro® systems come with a 20′ 12AWG cable. Sometimes a customer may want to mount the solar panels at a different location than the solar controller/batteries. This can be done as long as you understand that if you extend the cable without increasing the wire diameter (AWG) you will create more loss in the cable run. There is a handy cable loss calculator that can be found at:

Using this calculator, you can find the loss with a given amperage, cable AWG and cable length.

The best way to reduce cable loss is to minimize the amperage travelling through the cable. For a given amount of watts, as the voltage goes up, the current (amps) goes down. For instance look at using a 160W solar panel system at different voltages. 160W/12V = 13.3A  160W/24V = 6.7A  160W/40V = 4A

A big advantage of using an MPPT solar controller is that the MPPT controller can typically handle up to 100V on the solar input and still charge a 12V or 24V battery. In our example of a 160W solar array, the array is made up of two 80W 12V solar panels. Each panel puts out about 20VDC. If you wire the panels in series the voltage adds to about 40V. You can see in the above example that with 160W solar array and 40V configuration, the current drops to only 4A which will result in a very low cable loss as compared to 13.3A in a 12V configuration using a PWM solar controller.

If using an MPPT controller isn’t an option for your application, the options you have would be to

  1. use the highest battery voltage possible
  2. use a larger wire diameter (AWG).

The 12AWG 20′ cable that ships with the systems can be extended by using a larger diameter wire like 10AWG or 8AWG or even larger. The Tycon PWM solar controller can handle as large as 10AWG wire but you can cut the 12AWG 20′ cable and use it to connect to the solar controller and solar panel and in between, use a long 8AWG or 6AWG cable and connect to the 12AWG wire using wire nuts. Using the larger diameter wire for the long runs will reduce your cable loss. The very short runs of 12AWG wire will have insignificant loss.