Hybrid Car – More Fun with Less Gas

How many panels ? ( to run 230 volt sprinkler pump 30 minutes a day?) - Page 32

register ::  Login Password  :: Lost Password?
Posted by Ron Rosenfeld on July 30, 2008, 12:40 pm
On Wed, 30 Jul 2008 01:08:42 -0700 (PDT), bealiba@gmail.com wrote:

Given your habit of frequently using terminology that you hope will be
misinterpreted, it is often difficult to know what you mean.

George you repeatedly claimed that

represented the minimum requirements for a battery.  The fact that no
particular battery was specified is irrelevant when you define minimum

Ah, now it is typos as the reason.  It surely couldn't be inaccurate user

What about this:

We still don't know where you got the 238 Ahr capacity rating from.

According to the manufacturer (Battery Energy) data on their web site:

Model        2AS620
Nominal volts    2

1 hr    161
2 hrs    206
3 hrs    245
4 hrs    266
5 hrs    283
8 hrs    335
10 hrs    342
12 hrs    363
24 hrs    417
48 hrs    513
120 hrs    620
168 hrs    646
240 hrs    650

Was this another typo?  Or just another example of inaccurate user input?

So, to sum up George's recommendations based on the OP's request, for
running a pump rated at 2500 watts for 1/2 hr per day, in

GG: (1st try) 154 panels

GG: (2nd try)  17- 50W Panels

GG: (3rd try)  (C5 / C12) = 10.3 panels rated at 41.16W
 Capacity of battery bank at 100 hr rate (B12 x B10) = 180

GG: (4th try) 10.43 panels rated at 50W (BP350)
  4 - 2AS620 batteries wired in parallel

GG: (5th try) 10.43 panels rated at 50W (BP350)
  6 - 2AS620 batteries wired in series

However, the manufacturer data sheet on its web site indicates the battery
that George is now specifying has only a 161 Ahr capacity at the one hour
rate.  http://www.batteryenergy.com.au/02_suncycle_discharge.htm

So can George explain where the manufacturer has made an error and can
provide a data sheet that shows the 1 hr capacity to really be 238Ah?

Not that it matters too much, because even using the mfg published data for
panels and batteries; and also using the TMY2 data from NREL for a typical
year at the OP location, George's 5th try finally works!

Good boy, George.  It only took weeks of prodding before you came up with a
reliable system recommendation using battery storage.

The simulations show that it's a bit larger than it needs to be for a
"typical year", 11 panels vs 9 panels.  

(There's that pesky "user input" again, to be blamed).

So that would be  about $,000 excess, depending on net costs of the panels
and installation.  But at least this one will work, even though you may
have input the wrong data for the battery.

Posted by bealiba on July 30, 2008, 2:26 pm

So you say. But then that's probably another lie anyway.

Your praise is so overwhelming, not. First you say the battery is
wrong then you say it is right. you're a lot like the weather man on
the news. Rain and sun somewhere today, unless it doesn't.

When you can show that the formula is incorrect then you can crow. Now
try being a real man and do  total system sizing. Showing all the
calculations and user input. Oh, silly me, you never will. You talk I

Posted by Ron Rosenfeld on July 30, 2008, 4:16 pm
 On Wed, 30 Jul 2008 07:26:33 -0700 (PDT), bealiba@gmail.com wrote:

One that you could easily refute, if you were able to.  I even provided you
the link to the data on the mfg web site.  But I guess that's too much
trouble.  You'd rather just make up your data and, when corrected, instead
of admitting it, post nonsense.

I never wrote that 2AS620 was the wrong battery.
I did write that it was wrong to use 4 of them, when YOU posted:

I also said your minimum battery requirements were wrong, when YOU posted:

And I said that your 2AS1100 was oversized compared with YOUR minimum
requirements when you suggested it, because its 100 hr rating is almost six
(6) times YOUR posted minimum requirements.

After many posts, you finally realized that your 180Ah minimum requirement
should have been at the 30 minute rate, and not the 100 hr rate.  But then
you were left with trying to explain:

Tough to BS when your writings are preserved on the newsgroup, though.

You can't recognize the obvious.

Since your spreadsheet gives so many different results, its inadequacy is a

And when you posted:

where you divide 108 / 238 and come up with 4

and then tried to blame this on typos, you lost even more credibility.

And of course, you also posted:

Where you divide 12 / 2 and come up with 1

And blame that on typos also.

If only you would walk.
If only you were a "real man" and could admit to making a mistake.

I've already posted my array-sizing calculations.  But you claimed they
were excessive even though I recommended 10 panels and you recommended more
than that.

And when you try to BS with typos, you post the following "correction" to
your typos:

which does NOT agree with what is on the mfg site.  But you are not able to
explain the difference.

You also post:

which also does not agree with the mfg spec sheet for that module.  (Here's
a link to the spec sheet on the mfg site:


The rating at NOCT is not at 14 VOLTS, but rather at 17.5V.  You keep
making this error, in spite of it having been pointed out to you before,
several times.  At 14V, the current output is higher, but the power is

Clearly, with errors in calculations and in your USER inputs, it was pure
serendipity and multiple attempts that finally brought you to the point of
a usable system.  As a matter of fact, the 30 minute capacity of the
2AS620, although not posted by the mfg, can be easily calculated, using
Peukert's exponent, from the mfg data to be 125Ah -- a fraction of the
180Ah 30 minute capacity you are NOW claiming to represent the minimum

If you want, you can confirm the calculations using the calculators at the
web site Wayne referred you to; and the mfg data using the link I posted
for you.

But you'll probably just claim that these data are lies.

Posted by bealiba on July 30, 2008, 7:21 pm
Just so everyone can work from the same page I suggest that we use
"peukert3.xls" as it operates by adjusting the specified battery
capacity to the "Peukert Capacity" then showing run times calculated
using the usual T=C/In

Posted by Ron Rosenfeld on July 30, 2008, 9:44 pm
 On Wed, 30 Jul 2008 12:21:46 -0700 (PDT), bealiba@gmail.com wrote:

I suppose you mean T=C/I^n

Where are you going with this?

By "peukert3.xls" do you mean
http://www.smartgauge.co.uk/calcs/peukert3.xls  ?

Since it produces the same results as my own Excel spreadsheet, I have no

What are you going to use for inputs?

Bad input is one of the items that has been critical in your efforts to

This Thread
Bookmark this thread:
  • Subject
  • Author
  • Date
please rate this thread