Ok, thanks for the explanation. I checked and my panel says 100watts, 21.6v and 6.10a. It is a Renogy and yes, it is prewired. It's two panels connected by a hinge allowing it to fold. There is a black box on the back of both panels and wire connecting the two black boxes together. Then one wire from each side going to the charge controller. From the charge controller, there are two with alligator type of clips I use to connect to the battery. It's really easy to use and pretty effective. I was hoping I'll be able to wire it with others, to step up the voltage in order to charge a 24v battery, but now I'm not sure if that particular panel will let me.