alt.energy.homepower

Bob Adkins wrote:
> Hey guys. Long time no see. :)
>
>
> I'm baffled by a seemingly ambiguous problem.
>
> I know a 100w solar panel puts out ~20v no load. So that's 100w/20=5
> amps theoretically in full sun.
>
> Now,,, when the charge controller kicks the voltage down to ~14v, does
> the battery then charge at 100w/14v= amps?

To know for sure how much current you'll get at a given voltage (or vice
versa), you have to know the solar panel's I-V curve. A bit about the
I-V curve is explained here:

/encyclopedia/I/

The only way to know how much your panel will produce at 14V is to find
14V on the I-V curve for and read the associated current from the chart.
You can put a maximum power point tracker (MPPT) between the panel and
the charge controller to ensure the panel always operates at the maximum
power point, regardless of the charge controller's demands, but whether
that's economical depends on your situation.