Geoff Schultz wrote:
Get a controller that diverts voltage above the maximum charging voltage of
the battery to a resistive load. In my case this is the water heater with
12V and 120V heater elements. 100% of the power of the solar panels will
go to charging the panels up to that point. You can't produce more power
than the panels are generating.

I personally use a Morning Star TriStar controller to control both my wind
generator and solar panels and it works great.

-- Geoff
So, are you saying that if the panels are putting out 17 volts and the
battery is only taking 14, then 3 volts are applied to the heater? I
don't think that's the way it works.