The External Battery Remote Connection Cable is 3ft long and allows you to add any other battery besides a Titan battery to the Titan solar generator. Common external batteries are Lion Energy UT 1300, Battle Born, and others.
This includes a safety measure with a built-in 150a breaker to protect the battery and Titan in case too much power is drawn.
***Very Important: External batteries must be wired in 24v if they are not already 24v. Any battery that is added to a Titan must be within .5v of the batteries that are onboard the Titan.