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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From: [email protected] [mailto:[email protected]] On Behalf Of Nick Pugh Sent: 31 October 2012 11:16 To: [email protected]; 'Justin Foley'; [email protected] Cc: [email protected]; Travis Steen; [email protected]; Trey Oliver; [email protected]; Amy Henson; Chase Savoy; [email protected]; ThomasEbosch@gmail. com; [email protected]; Nick Pugh; [email protected] 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
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