Jeff wrote in
:

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.

That's exactly what I'm saying. It's called Diversion Mode and on the
controller you set the maximum voltage which is allowed to be applied to
the batteries. Anything above that is diverted to the load.

The only time that this occurs is when the batteries are fully charged.
The vast majority of the time the charging load of the batteries drops the
output of the solar cells to a voltage less than the maximum allowable
voltage and thus nothing is diverted.

For details please see the manual:
http://www.mrsolar.com/pdf/morningstar/TS_Manual.pdf


-- Geoff