Charge controllers-voltage surge

[Reno]

I do not have a charge controller and watching my mill charge batteries I always wonder if a charge controller is set by voltage what is happening when the voltage is spiking in gusting winds but the batteries are not fully charged. I know the viltage rises and amps drop when batteries are at or near full does this have something to so with it.

Thanks

[alcul8r]

Reno,

The answer will depend on what sort of charge controller you have.

Some are just a voltage regulator to prevent overcharging.

Some use PWM, or pulse width modulation to smooth the transition from charging to not charging.  My Bergey controller first uses PWM to the dump load to control input, also PWM into the batteries to control output.

The Bergey also has a booster for when you are not getting enough voltage.  I have seen it suck the input down below 10 volts to charge 24V batteries.

Rex