[Power] Good day for a solar panel test

Richard Smith richard at laptop.org
Wed Jul 11 16:02:59 EDT 2012


> First thing to note is the power cable is short but it is not far from an ideal length IMO.

Yep.  That's going to be fixed in the production units.  Proposed
length is 1.5 meters.  Just like the previous GP panel.  What do you
consider the ideal length?

> Too long is a pain I've found in the past.

How so?  It needs to be long enough that the panel can go in the sun
and the user or XO in the shade.  The samples that are getting used in
Madagascar highlighted this because they were concerned about having
the XO in the direct Africa sun.  It gets very hot and charging makes
it even hotter.  The laptop is only rated for 50 degC operating temp.

> That Voc 18V, 1.140A Isc looks to make it ~15W @12V?

15W is the rated output of the panel but unless you have a lot more
than 1000W/m^2 you won't get that.  When it gets to NOC it derates.
See the data in my link below.

Here's some more technical data on the samples.  This is for some
pre-samples samples. :)  So you will notice some slight differences
between whats in this info and what you actually have.

http://dev.laptop.org/~rsmith/auria_solar_sample/

Please don't copy it to the wiki.    Its for samples and not the
official product.  Its not secret but I don't want people to use that
info as the "official" info.  Just FYI for those of you who have
panels.

-- 
Richard A. Smith
One Laptop per Child


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