# Re: [WISPA] Powerconsumption

```Somewhere in the archives of this list, I posted a spreadsheet designed for
very high reliability  in northern climates.   ```
```
WRAP boards consume about 1A @12V.

That's 24AH per day.

range from minimal to around 4 hours / day average.

Thus, if are southern coastal, you can count on around 4 hours of sun per
day.

So, you need 24 AH
divide by 4 hours of sun average
6 amps needed for 4 hours.
2 Kyocera KC65T's are 3.6 amps ea
www.wholesalesolar.com

Now, you need batteries.  First, estimate your longest possible period
without full sun...  3 days?  5 days?  10 days?

for me, I had figured 10 days.

So.. 10 days X 24 ah = 240 ah.  Since you should not discharge more than
50%, i'll need 240 / .5 or 480 AH of battery c apacity @ 12V.  That way,
even long term weather won't damage the batteries.

Your solar panels should go in series, with one of these:
http://www.wholesalesolar.com/products.folder/controller-
folder/sb2000wdisplay.html

It makes the panels a LOT more efficient and produce considerably more
power over the long term.

Now, if you use the logic and formulas here, you should be able to roughly
calculate for any size load and location.  Use "insolation" charts for your
location.  They come with w/m ratings, and fortunately, those happen to be
roughly equivalent to sun hours per day.

On Sun, 4 Feb 2007 15:40:43 -0600, Mark McElvy wrote
> I am trying to wrap my head around calculation power consumption
> and run time calculations. I used a Kill-A-Watt, plugged in a WRAP
> board w/ one each CM-9 and WLM54g. The CM-9 is the backhaul and
> WLM54G is the AP with two clients connected. The following data
> was collected.
>
> 330 Hours
> 1.85 KWH
> ..07 A
> 05 WATT
> 07 VA
>
> I could use some help deciphering.
>
> I need to understand battery capacities and how to calculate run times
> based on the above info and a given battery size. Also charging
> with solar, how to calculate charging capacity needed.
>
> Mark
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mark at neofast dot net
neofast, Inc, wireless internet for the Walla Walla Valley and Blue
Mountains
541-969-8200

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```