---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 05/12/13: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:15 AM - Re: Re: Crowbar OV Module (Sacha) 2. 12:50 AM - Re: Re: Crowbar OV Module (jan) 3. 06:45 AM - Re: Re: Crowbar OV Module (Robert L. Nuckolls, III) 4. 07:04 AM - Re: Re: Crowbar OV Module (jan) 5. 06:53 PM - Lithium batteries for OBAM aircraft (David Josephson) 6. 07:43 PM - Re: Lithium batteries for OBAM aircraft (Henador Titzoff) ________________________________ Message 1 _____________________________________ Time: 12:15:51 AM PST US From: Sacha Subject: Re: AeroElectric-List: Re: Crowbar OV Module Aliant is a brand belonging to ELSA Solutions. They're an Italian company ba sed in Bologna, whose main business is industrial automation and photovoltai c products. www.elsaweb.it Their website is in Italian and they use google translate which can yield so me interesting results. They claim that their batteries were designed with the Battery Management Sy stem as the central component which may explain why they haven't run into th e same problems as the other manufacturers. On 12 May 2013, at 02:18, "Robert L. Nuckolls, III" wrote: > Care and feeding of your lithium battery is > another matter entirely. I'd not heard of > the Aliant brand until your enquiry. Poking > around on the 'net I find that they've made > what appears to be a good penetration of the > sport vehicles markets. They filed for a trademark > > > > late last year. http://tinyurl.com/d2ohsjo > > I'm reading also where a part of their organization > has been awarded a contract to do safety > studies for the US Army to explore characteristics > based on environments and maintenance issues. > > SCRATCH THE ABOVE. > > Seems there's a company called Alliant/Valence that makes > a lot of aerospace/military hardware. These are the > folks getting the testing job . . . NOT Aliant > > Bob . . . > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 2 _____________________________________ Time: 12:50:44 AM PST US From: jan Subject: RE: AeroElectric-List: Re: Crowbar OV Module I know Valence very well. Been using them for a few years in other applications - They ran out of money some time ago. Looks like they are now doing work with this Aliant company .. Valence had a good technology and a good BMS system - Also the Iron Phosphate technology is pretty safe - Not as energy dense or as powerful as Cobalt . To not damage the cells - over voltage under voltage and temperatures all have to be watched and maintained to not damage the cell. _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Sacha Sent: 12 May 2013 07:56 Subject: Re: AeroElectric-List: Re: Crowbar OV Module Aliant is a brand belonging to ELSA Solutions. They're an Italian company based in Bologna, whose main business is industrial automation and photovoltaic products. www.elsaweb.it Their website is in Italian and they use google translate which can yield some interesting results. They claim that their batteries were designed with the Battery Management System as the central component which may explain why they haven't run into the same problems as the other manufacturers. On 12 May 2013, at 02:18, "Robert L. Nuckolls, III" > wrote: Care and feeding of your lithium battery is another matter entirely. I'd not heard of the Aliant brand until your enquiry. Poking around on the 'net I find that they've made what appears to be a good penetration of the sport vehicles markets. They filed for a trademark ALIANT late last year. http://tinyurl.com/d2ohsjo I'm reading also where a part of their organization has been awarded a contract to do safety studies for the US Army to explore characteristics based on environments and maintenance issues. SCRATCH THE ABOVE. Seems there's a company called Alliant/Valence that makes a lot of aerospace/military hardware. These are the folks getting the testing job . . . NOT Aliant Bob . . . D======================== ========= D======================== ========= D======================== ========= D======================== =========

I know Valence very well. Been using them for a few years in other applications – They ran out of money some time ago. Looks like they are now doing work with this Aliant company ..  Valence had a good technology and a good BMS system – Also the Iron Phosphate technology is pretty safe – Not as energy dense or as powerful as Cobalt  .

 

To not damage the cells – over voltage under voltage and temperatures all have to be watched and maintained to not damage the cell.

 

 

 


From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Sacha
Sent: 12 May 2013 07:56
To: aeroelectric-list@matronics.com
Subject: Re: AeroElectric-List: Re: Crowbar OV Module

 

Aliant is a brand belonging to ELSA Solutions. They're an Italian company based in Bologna, whose main business is industrial automation and photovoltaic products. 

Their website is in Italian and they use google translate which can yield some interesting results.

They claim that their batteries were designed with the Battery Management System as the central component which may explain why they haven't run into the same problems as the other manufacturers. 


On 12 May 2013, at 02:18, "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric. com> wrote:

  Care and feeding of your lithium battery is
  another matter entirely. I'd not heard of
  the Aliant brand until your enquiry. Poking
  around on the 'net I find that they've made
  what appears to be a good penetration of the
  sport vehicles markets. They filed for a trademark
 
ALIANT 

  late last year. http://tinyurl.com/d2ohsjo

  I'm reading also where a part of their organization
  has been awarded a contract to do safety
  studies for the US Army to explore characteristics
  based on environments and maintenance issues.
 
  SCRATCH THE ABOVE.

  Seems there's a company called Alliant/Valence that makes
  a lot of aerospace/military hardware. These are the
  folks getting the testing job . . . NOT Aliant


  Bob . . .

 
 
 
 
 <
/font>
http://www.matronics.com/Navigator?AeroElectric-List
http://forums.matronics.com
http://www.matronics.com/contribution<
/font>
 



________________________________ Message 3 _____________________________________ Time: 06:45:28 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Crowbar OV Module At 03:01 AM 5/12/2013, you wrote: >I know Valence very well. Been using them for a >few years in other applications ' They ran out >of money some time ago. Looks like they are now >doing work with this Aliant company .. Valence >had a good technology and a good BMS system ' >Also the Iron Phosphate technology is pretty >safe ' Not as energy dense or as powerful as Cobalt . > >To not damage the cells ' over voltage under >voltage and temperatures all have to be watched >and maintained to not damage the cell. > > Are you saying there IS a cooperation between Aliant the battery guys and Alliant/Valence the aerospace/ military guys? Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:04:51 AM PST US From: jan Subject: RE: AeroElectric-List: Re: Crowbar OV Module Bob, I will make a few phone calls next week and see what I can find out... Jan _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: 12 May 2013 14:43 Subject: RE: AeroElectric-List: Re: Crowbar OV Module At 03:01 AM 5/12/2013, you wrote: I know Valence very well. Been using them for a few years in other applications - They ran out of money some time ago. Looks like they are now doing work with this Aliant company .. Valence had a good technology and a good BMS system - Also the Iron Phosphate technology is pretty safe - Not as energy dense or as powerful as Cobalt . To not damage the cells - over voltage under voltage and temperatures all have to be watched and maintained to not damage the cell. Are you saying there IS a cooperation between Aliant the battery guys and Alliant/Valence the aerospace/ military guys? Bob . . .

Bob,

 

I will make a few phone calls next week and see what I can find out…

 

Jan

 


From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III
Sent: 12 May 2013 14:43
To: aeroelectric-list@matronics.com
Subject: RE: AeroElectric-List: Re: Crowbar OV Module

 

At 03:01 AM 5/12/2013, you wrote:

I know Valence very well. Been using them for a few years in other applications – They ran out of money some time ago. Looks like they are now doing work with this Aliant company ..  Valence had a good technology and a good BMS system – Also the Iron Phosphate technology is pretty safe – Not as energy dense or as powerful as Cobalt  .
 
To not damage the cells – over voltage under voltage and temperatures all have to be watched and maintained to not damage the cell.
 
 
 


  Are you saying there IS a cooperation between Aliant
  the battery guys and Alliant/Valence the aerospace/
  military guys?



  Bob . . .

 
 
http://www
.matronics.com/Navigator?AeroElectric-List
http://forums.matronics.com
http://www.matronics.com/
contribution
 



________________________________ Message 5 _____________________________________ Time: 06:53:15 PM PST US From: David Josephson Subject: AeroElectric-List: Lithium batteries for OBAM aircraft I attended the Electric Aircraft Symposium put on by CAFE a few weeks ago. One of the speakers was Dr Eric Darcy of the NASA Johnson Spaceflight Center in Houston, on "Mitigating Catastrophic Failures with Li-ion Batteries." He has the task of figuring out how to change out the batteries in the International Space Station, and for now they are planning to use the same GS-Yuasa LVP lithium cobalt cells that are in the Boeing 787. As you might imagine, he's not quite ready to give the green light for using them in the Space Station. We learned a lot about keeping lithium batteries from doing bad things, and about some things that amateurs can do to test cells for likely problems. All variants (LiPo, LiFe, Li-poly etc.) have the same thermal runaway problem that seems to have been the failure mechanism in the incidents to date, some just take more abuse to start it. Besides that, the lithium cobalt chemistry (used in the 787, Tesla cars, laptops and many other applications) uses a flammable electrolyte that isn't used in the lithium/manganese or lithium/iron used in some others. He thought they were all just as dangerous, though, and were subject to all of the same problems. Once the cell develops a short, all of its energy gets released as heat, potentially causing the neighboring cells to do the same. Of course the known limits for charge voltage and discharge current must be followed. You also need to avoid mechanical damage that could cause a short between the plates of the cell (drive a nail through and they will explode.) But the famous failures so far have probably not been due to any of those things. Dr. Darcy was clear to point out that he didn't know what happened with the 787 batteries but discussed failures that he had seen in many other cell types, both prismatic and "jelly roll." Two main events can happen: a small inclusion like a tiny snip of metal or dirt can be trapped in the separator between the battery plates that ultimately starts forming a current path between them, or the edges of the plates which are supposed to be overlapped by insulating material can come close to touching if they are misaligned, causing the same sort of contact. Many of these cell failures can be caught long before the cell melts down, because each of these almost-short-circuits usually causes some discharge before the full battery current can flow. Darcy suggested two tests that anyone could do. One is when receiving a lot of cells, that have been partially charged and then shipped a long distance, measure the open circuit voltage of each one. They should all be very close to each other, like within 1%. The other test is to charge each cell to full capacity and then discharge to 10%, say 3.25 volts. Disconnect the charger and measure the open circuit voltage a few times a day for two weeks. Good cells will climb at a uniform rate back to their original voltage, suspect cells will have a very different curve, either much slower or much faster (typically followed by a droop). At the end of two weeks, trust the cells that are all clustered with the same open circuit voltage. I would imagine that the folks packaging cells into aircraft batteries do some of this testing, but it's good to know that some simple methods can be used to check cells beforehand. -- David Josephson ________________________________ Message 6 _____________________________________ Time: 07:43:22 PM PST US From: Henador Titzoff Subject: Re: AeroElectric-List: Lithium batteries for OBAM aircraft David,=0A=0AThanks for giving us insight on what Dr. Darcy said at the JSC on mitigating catastrophic failures with lithium batteries. I have the opin ion that lithium batteries are not ready for prime time in aircraft, but I can always be talked out of it if someone has done sufficient analysis and testing to prove me wrong.- I see that Dr. Darcy isn't ready to install l ithium cobalt batteries in the ISS.- I wonder if he would install them in his OBAM aircraft and fly his family around?- I suspect not.=0A=0A=0AI h ave a problem with his advice about how to detect cell failures.- We typi cally do not have access to cells, because they are packaged in series to b uild up the voltage to 12V+. I certainly wouldn't drill into the packaging material to measure individual cells. Therefore, we only have access to two points: GND and POS.- Without destroying the battery's usefulness, we ca n't perform the cell tests he mentioned.=0A=0A=0ADoes anyone see it differe ntly?=0A-=0AHenador Titzoff=0A=0A=0A________________________________=0A F rom: David Josephson =0ATo: aeroelectric-list@matronic s.com =0ASent: Sunday, May 12, 2013 9:51 PM=0ASubject: AeroElectric-List: L ithium batteries for OBAM aircraft=0A =0A=0A--> AeroElectric-List message p osted by: David Josephson =0A=0AI attended the Electri c Aircraft Symposium put on by CAFE a few weeks =0Aago. One of the speakers was Dr Eric Darcy of the NASA Johnson =0ASpaceflight Center in Houston, on "Mitigating Catastrophic Failures with =0ALi-ion Batteries." He has the ta sk of figuring out how to change out the =0Abatteries in the International Space Station, and for now they are =0Aplanning to use the same GS-Yuasa LV P lithium cobalt cells that are in =0Athe Boeing 787. As you might imagine, he's not quite ready to give the =0Agreen light for using them in the Spac e Station.=0A=0AWe learned a lot about keeping lithium batteries from doing bad things, =0Aand about some things that amateurs can do to test cells fo r likely =0Aproblems.- All variants (LiPo, LiFe, Li-poly etc.) have the s ame thermal =0Arunaway problem that seems to have been the failure mechanis m in the =0Aincidents to date, some just take more abuse to start it. Besid es that, =0Athe lithium cobalt chemistry (used in the 787, Tesla cars, lapt ops and =0Amany other applications) uses a flammable electrolyte that isn't used in =0Athe lithium/manganese or lithium/iron used in some others. He t hought =0Athey were all just as dangerous, though, and were subject to all of the =0Asame problems.=0A=0AOnce the cell develops a short, all of its en ergy gets released as heat, =0Apotentially causing the neighboring cells to do the same. Of course the =0Aknown limits for charge voltage and discharg e current must be followed. =0AYou also need to avoid mechanical damage tha t could cause a short =0Abetween the plates of the cell (drive a nail throu gh and they will =0Aexplode.) But the famous failures so far have probably not been due to =0Aany of those things. Dr. Darcy was clear to point out th at he didn't =0Aknow what happened with the 787 batteries but discussed fai lures that he =0Ahad seen in many other cell types, both prismatic and "jel ly roll." Two =0Amain events can happen: a small inclusion like a tiny snip of metal or =0Adirt can be trapped in the separator between the battery pl ates that =0Aultimately starts forming a current path between them, or the edges of =0Athe plates which are supposed to be overlapped by insulating ma terial =0Acan come close to touching if they are misaligned, causing the sa me sort =0Aof contact.=0A=0AMany of these cell failures can be caught long before the cell melts =0Adown, because each of these almost-short-circuits usually causes some =0Adischarge before the full battery current can flow. Darcy suggested two =0Atests that anyone could do. One is when receiving a lot of cells, that =0Ahave been partially charged and then shipped a long d istance, measure =0Athe open circuit voltage of each one. They should all b e very close to =0Aeach other, like within 1%. The other test is to charge each cell to =0Afull capacity and then discharge to 10%, say 3.25 volts. Di sconnect the =0Acharger and measure the open circuit voltage a few times a day for two =0Aweeks. Good cells will climb at a uniform rate back to their original =0Avoltage, suspect cells will have a very different curve, eithe r much =0Aslower or much faster (typically followed by a droop). At the end of two =0Aweeks, trust the cells that are all clustered with the same open circuit =0Avoltage.=0A=0AI would imagine that the folks packaging cells in to aircraft batteries =0Ado some of this testing, but it's good to know tha t some simple methods =0Acan be used to check cells beforehand.=0A=0A--=0AD = ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.