Hi All,
Further to February's Aus soaring discussion on Lithium batteries, this month's issue (June 2013) of Silicon Chip magazine has a an interesting and informative article on the latest developments in this technology. John Parncutt From: [email protected] [mailto:[email protected]] On Behalf Of John Parncutt Sent: Tuesday, 26 February 2013 5:58 PM To: 'Discussion of issues relating to Soaring in Australia.' Subject: Re: [Aus-soaring] LiFePo4 Hi David, The link you provide is to exactly the same model of Shorai battery I have been evaluating. The load tests I have done give it an actual capacity of 4 A/H (far from the stated capacity of 14 A/H). I have attached an image of the results for your info, for comparison the results on one of our clubs existing (used) lead acid glider batteries is also included. This clearly demonstrates the ability of the Lithium battery to provide an almost constant voltage across its complete discharge period whereas the lead acid battery voltage continually drops to a point where some of our instrumentation and particularly the radio in transmit mode may fail about halfway through discharge. If you note the Shorai literature states an equivalent A/H rating to that of a 14 A/H lead acid battery not an actual A/H rating. This is misleading and I think a bit of sales spin! The comparison I think is based on the Cold Cranking capacity of the battery, ie. the ability to delivery large currents to a starter motor bearing in mind these batteries are designed to replace wet lead acid motorcycle batteries. The bottom line is that the 14 A/H Shorai battery will not deliver 1 amp continuously for 14 hours, well certainly not the one I tested!! John Parncutt From: [email protected] [mailto:[email protected]] On Behalf Of David Conway Sent: Tuesday, 26 February 2013 4:38 PM To: 'Discussion of issues relating to Soaring in Australia.' Subject: Re: [Aus-soaring] LiFePo4 Agreed; something like this would be better http://www.shoraipower.com/s.nl/it.A/id.91/.f 14AH - twice that of a normal SLA glider battery - and less than half the weight @ 662g David From: [email protected] [mailto:[email protected]] On Behalf Of Future Aviation Sent: 26 February 2013 15:02 To: 'Discussion of issues relating to Soaring in Australia.' Subject: Re: [Aus-soaring] LiFePo4 Hi Ian >From a safety point of view this is much better than what the Boeing dreamliner is using. However, I would never put a battery like that in a glider unless it is securely placed in a much more impact resistant enclosure. Kind regards Bernard _____ From: [email protected] [mailto:[email protected]] On Behalf Of Ian Mc Phee Sent: Tuesday, 26 February 2013 2:15 PM To: Discussion of issues relating to Soaring in Australia. Subject: [Aus-soaring] LiFePo4 About $87 and notice a new Arcus M was fitted at factory with something similar. This is NOT what B787 is using. Ian M http://www.hobbyking.com/hobbyking/store/__22656__ZIPPY_Flightmax_8400mAh_4S 2P_30C_LiFePo4_Pack_AUS_Warehouse_.html
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