The example resistors in the adjustable section are R1 always 3K
and R2, varies. You can double R1 and double R2 and get the
same output voltage.
So I will use an R1 of 6.8K
with a base resistor, and an adjustable of
base
(would be for 13.5-13.8 according to powerstream sla page) volts)
so let's do the math
for 13.65 float voltage.
6k( /(13.65/1.23) - 1 )


13.65 / 1.23 - 1 == 10.09756

6k / 10.09756 == 594.31

There is a 590 resistor in e24 or something. Let's do that.

That is base.

For lowest voltage of 1.2volts (single nicad charged by sun)
though nicads probably have memory issues, but they are cheap
so who cares... (I think nimh might be better?)

1.2 = 1.23( 6k/??? + 1)

So solve for R2 which is unknown

However my earlier math is wrong, since I need a 5900 resistor




13.65 / 1.23 - 1 == 10.09756

5900 / 10.09756 == 584.29

So still a 590 resistor... Close as we can get. Well,
there is a 583 on my chart, so

5900
583


Base is 583, 5900 is R1

Now what is the adjustable.

Solve for R2, and remember you need the difference
And can't go below reference...
R2 == 5900 / (1.3/1.23 - 1)
1.3/1.23 - 1 == 0.0569
5900 / 0.0569 == 103690

Quite a difference. We need to jump from 100K to 583.
So I would add a 100K and that should get me close to 1.4 volts.
Hopefully close enough. Done.