Using a high power resistor as a dump load
When choosing a dump load for your charge controller, you need to find heater or heaters that will: Be able to dump the maximum current your combined wind and solar systems will throw at it at once. Not draw more current than the charge controller is able to handle. (Which is the number in the name of the controller – e.g. C40 can handle 40 amps maximum.) A neat solution to finding a dump load for a charge controller is to use a big wire wound resistor that you can buy from an electronic component supplier. Look for ones with low resistance and high power rating. There are not very many to choose from, and their stock is always changing. The resistor has two important numbers associated with it: resistance and power rating. Resistance determines how much current it will dump in your system and the power rating is a guide to the maximum safe wattage it can burn off without over-heating. When choosing a resistor/heater for a charge controller we need t...