[amsat-bb] Re: [CubeSat] (no subject)

[Craig Clark]

Hi Nick, 

 

This is Craig from Clyde Space.  I thought I'd best respond to your
email since you suggest that there is a performance issue with one of
our products to the entire CubeSat community.  

 

Our Lithium Polymer cell was selected following an ESA study into
lithium polymer technology.  We then were awarded another contract from
ESA to characterise and qualify the cell for space, which went extremely
well.  In addition, our battery has been tested by NASA from a safety
perspective to allow it to fly on the shuttle and now on the ISS -
unlike other cells tested at the time, our cells passed these tests no
problem (I can supply this test report if you wish).  Finally, we have
supplied over 300 CubeSat batteries in the last 5 years and we now have
several batteries on orbit, including the SDL DICE mission, US Army
nanosatellites, NRO Colony 1 buses, plus many more.  To my knowledge,
our battery is the most tested, most widely used and most successful of
any CubeSat battery in the World and I would be happy to put you in
touch with our customers to verify this if you wish.  This would not be
the case if there were performance issues with our cell.

 

In terms of performance below zero, all lithium ion based technology
suffers from performance degradation at low temperatures due to the
internal resistance of the cell increasing, resulting in higher losses
internally and lower available capacity.  You can develop specific low
temperature cells, but this is typically at the detriment to other
characteristics of the cell, such as energy density, charge rate, etc.
There is plenty of information on the performance of our cell at
different temperatures and charge/discharge rates on our website in our
Battery User Manual (you can find this here:
http://www.clyde-space.com/cubesat_shop/batteries/16_cubesat-standalone-
battery).  Also, we have two papers on our website that detail the tests
performed on the cells and these can be found here:
http://www.clyde-space.com/about_us/papers_and_presentations.  

 

I hope this information helps.  I can supply much more information if
you require it, but don't want to clog up peoples inboxes.  

 

There are now a few small, CubeSat companies who are pushing forward
with innovation and lower cost spacecraft products, which is in turn
enabling more and cheaper space missions; this is something that the
small satellite community cannot rely on the large space companies to
do.  These small companies all rely on business from many people on
these mailing lists, so please may I ask that care is taken in posting
to these lists with rumours.  Please also, if anyone does have concerns,
contact me directly as we have all the analysis, test and flight
heritage data you could need.

 

Thank you for your time,

Craig.

 

Craig Clark
www.clyde-space.com <http://www.clyde-space.com/> 

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| Registered in Scotland No. SC285287
| at 123 St Vincent Street Glasgow G2 5EA.

 

From: cubesat-bounces at cubesat.org [mailto:cubesat-bounces at cubesat.org]
On Behalf Of Nick Pugh
Sent: 31 October 2012 11:16
To: cubesat at cubesat.org; 'Justin Foley'; Amsat-bb at amsat.org
Cc: PaulDarby at aol.com; Travis Steen; henry at louisiana.edu; Trey Oliver;
wxo4547 at louisiana.edu; Amy Henson; Chase Savoy; vxb3736 at louisiana.edu;
ThomasEbosch at gmail. com; johnn902 at gmail.com; Nick Pugh;
james.palmer.iii at gmail.com
Subject: [CubeSat] (no subject)

 

Hi All

I have just returned from the AMSAT conference in Orlando FL one of the
European  is no longer flying the Clyde Space batteries because of
performance issues. I would like to know the group thoughts on their
batteries and lithium batteries in general.

 

The AMSAT team is warning us about charging batteries below 0 deg c. In
talking to many teams on ElaNa 4 there does seem too much concern about
charging batteries cold. Please let us know your thoughts. If you desire
we will not publish your responses.

 

 

 

 

Thanks

 

nick      ARS K5QXJ EM30xa 30.1N 92.1W

Office   337 593 8700

Cell      337 258 2527

 

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