This product allows you to set voltage limits to turn your heating element on and off. This allows you to use any excess solar power to heat water.
 
There is also the option to add a high current relay, as the device in this product is not rated for more than 10 amps. You can find out how to programme the Solaris by watching our video tutorial here.
 
This product can also be used to activate the D+ signal on a DC-DC charger. However, it will not work with smart alternators.