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Lithium batteries redux

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nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jan 08, 2013 10:02 am Post subject: Lithium batteries redux

This morning's news included a bit concerning

a battery fire in a B787 on the ramp at Boston

airport.



http://tinyurl.com/bx3ww23



According to Skip Koss (and unlike the

Cessna ramp fire in the Citation) this fire appears

to have been controlled by individuals both trained

and equipped for dealing with a lithium fire.



A123 (manufacturer of the cells in the Cessna

battery) is shut down in bankruptcy although

I understand they've been purchased by a Chinese

interest.



Folks. I think it's pretty clear that the large

energy storage lithium products are not ready for

prime time on airplanes. There's a lot of ground

based history being made and new product development

being conducted which may ultimately evolve into

products with aviation-grade failure modes and risks . . .

let us wait and see.



Sometimes, the best way to drive a nail is with

a hammer and the best way to carry a reserve of

electrons is with lead-acid.



http://tinyurl.com/3atma44





   Bob . . .

rlborger(at)mac.com
Guest

Posted: Tue Jan 08, 2013 2:21 pm Post subject: Lithium batteries redux

Bob,



You may very well be correct, but I've gone out on a limb that I trust will support me and the aircraft.



I have purchased and installed an Aerovoltz 12 Cell EV02 LiFePo battery in my Europa.  The LiFePo battery is not supposed to be the fire hazard that the LiFe battery is.  It is amazingly small and light.  About 12 lbs lighter than the Odyssey it replaces.



I would not have done this had my Rotax 914 still been electric dependent with two electric fuel pumps.  about 2 years ago I replaced one of the electric pumps with an engine driven, mechanical pump so the engine will continue to operate should the electrics go totally dead.



So far, in 2 hours of testing on the ground and 1 hour in the air, all seems well.  It spins the Rotax on startup just like the Odyessy.  I purchased the special charger that will do fast, 5A, charge; slow. 2A, charge; maintenance, .1A, charge/float and cell balancing.  I have not done any time/power testing.  I need to see how long it will run the radio, transponder and GRT EIS 4000 and then test with only the radio and EIS.  When this is done, I will report the results.  



The seller of the battery did warn not to discharge below 9v as that would probably permanently damage the battery.  And if discharged to below 11 volts, it must be recharged in the cell balance mode.  



Isn't this one reason why we call it Experimental?



Blue skies & tailwinds,

Bob Borger

Europa XS Tri, Rotax 914, Airmaster C/S Prop.

Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

3705 Lynchburg Dr.

Corinth, TX  76208-5331

Cel: 817-992-1117

rlborger(at)mac.com



On Jan 8, 2013, at 12:00 PM, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> wrote:






This morning's news included a bit concerning

a battery fire in a B787 on the ramp at Boston

airport.



http://tinyurl.com/bx3ww23



According to Skip Koss (and unlike the

Cessna ramp fire in the Citation) this fire appears

to have been controlled by individuals both trained

and equipped for dealing with a lithium fire.



A123 (manufacturer of the cells in the Cessna

battery) is shut down in bankruptcy although

I understand they've been purchased by a Chinese

interest.



Folks. I think it's pretty clear that the large

energy storage lithium products are not ready for

prime time on airplanes. There's a lot of ground

based history being made and new product development

being conducted which may ultimately evolve into

products with aviation-grade failure modes and risks . . .

let us wait and see.



Sometimes, the best way to drive a nail is with

a hammer and the best way to carry a reserve of

electrons is with lead-acid.



http://tinyurl.com/3atma44





 Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Tue Jan 08, 2013 3:43 pm Post subject: Lithium batteries redux

My assessment sofar (FWIW).

The problem with LiFePO4 batteries is that they do not self-balance 

well. And the 4 cells are not reliably identical. The result is as follows.

You can either keep the cells balanced in the charged state, meaning 

that none of the four will ever go over 4 volts when the battery is 

charged at 14.4 V or so.

Or you can keep them balanced in the discharged state, meaning that none 

of the four will ever be driven below 2 volts when the battery is 

discharged to below 12 volts.

You cannot have both without sophisticated power electronics.

In our type of use we keep the battery balanced in the charged state. 

The danger then lies in deep discharging.

I will only use LiFePO4 if I can have a battery alarm that goes off when 

any one of the 4 cells goes below 2 volts (when discharging) or above 4 

volts (when charging). And an alternative source of backup energy if 

either occurs.

I would like to know in the meantime what level of battery monitoring is 

done on the accident Cessnas and Dreamliners...



Jan de Jong



On 1/8/2013 11:20 PM, Robert Borger wrote:

 	  Quote: 	
		   



 Bob,



 You may very well be correct, but I've gone out on a limb that I trust will support me and the aircraft.



 I have purchased and installed an Aerovoltz 12 Cell EV02 LiFePo battery in my Europa.  The LiFePo battery is not supposed to be the fire hazard that the LiFe battery is.  It is amazingly small and light.  About 12 lbs lighter than the Odyssey it replaces.



 I would not have done this had my Rotax 914 still been electric dependent with two electric fuel pumps.  about 2 years ago I replaced one of the electric pumps with an engine driven, mechanical pump so the engine will continue to operate should the electrics go totally dead.



 So far, in 2 hours of testing on the ground and 1 hour in the air, all seems well.  It spins the Rotax on startup just like the Odyessy.  I purchased the special charger that will do fast, 5A, charge; slow. 2A, charge; maintenance, .1A, charge/float and cell balancing.  I have not done any time/power testing.  I need to see how long it will run the radio, transponder and GRT EIS 4000 and then test with only the radio and EIS.  When this is done, I will report the results.



 The seller of the battery did warn not to discharge below 9v as that would probably permanently damage the battery.  And if discharged to below 11 volts, it must be recharged in the cell balance mode.



 Isn't this one reason why we call it Experimental?



 Blue skies & tailwinds,

 Bob Borger

 Europa XS Tri, Rotax 914, Airmaster C/S Prop.

 Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

 3705 Lynchburg Dr.

 Corinth, TX  76208-5331

 Cel: 817-992-1117

 rlborger(at)mac.com



 On Jan 8, 2013, at 12:00 PM, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> wrote:



 



 This morning's news included a bit concerning

 a battery fire in a B787 on the ramp at Boston

 airport.



 http://tinyurl.com/bx3ww23



 According to Skip Koss (and unlike the

 Cessna ramp fire in the Citation) this fire appears

 to have been controlled by individuals both trained

 and equipped for dealing with a lithium fire.



 A123 (manufacturer of the cells in the Cessna

 battery) is shut down in bankruptcy although

 I understand they've been purchased by a Chinese

 interest.



 Folks. I think it's pretty clear that the large

 energy storage lithium products are not ready for

 prime time on airplanes. There's a lot of ground

 based history being made and new product development

 being conducted which may ultimately evolve into

 products with aviation-grade failure modes and risks . . .

 let us wait and see.



 Sometimes, the best way to drive a nail is with

 a hammer and the best way to carry a reserve of

 electrons is with lead-acid.



 http://tinyurl.com/3atma44





   Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Wed Jan 09, 2013 5:59 am Post subject: Lithium batteries redux

Quote from PPRuNe forum:

"The APU and main batteries are quoted as a Lithium Manganese in my 787 

gen fam course notes. "

May not be LiFePO4 at all...



Jan de Jong

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Jan 13, 2013 7:10 am Post subject: Lithium batteries redux

 	  Quote: 	
		  

I would like to know in the meantime what level of battery 

monitoring is done on the accident Cessnas and Dreamliners...


	


   I cannot speak to specifics of the battery controls

   and monitoring systems in either airplane. However,

   I can speak to the qualification process for getting

   these batteries approved for installation.



   A number of AIRPLANE companies, not battery companies,

   have launched into breathtakingly expensive programs

   to gain some form of approval for use of lithium batteries

   on their products. These include Cessna, Boeing, Grumman

   and others.



   All players in the lithium game are intently aware

   of the unique risks offered by lithium batteries.

   They are also aware of the widely publicized litany

   of events involving lithium battery catastrophic

   failures.



   The testing of batteries is a legacy skill finely

   honed by over a century of field experience and

   lessons learned.



   See: http://tinyurl.com/akvhxv6  also



   http://tinyurl.com/b4f89jh



   The two airplanes you asked about enjoy a very

   high degrees of electronic systems management

   not the least of which are the batteries. Given

   the intense scrutiny and qualification expense

   associated with getting Li-Ion products onto

   both airplanes, it's a pretty sure bet that

   everyone believed that they'd touched all the

   bases.



   Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Sun Jan 13, 2013 9:01 am Post subject: Lithium batteries redux

Thank you Bob, very interesting.



As a follow-on I found this:

http://www.gsyuasa-lp.com/aviation-lithium-ion-markets

with this:

http://www.s399157097.onlinehome.us/SpecSheets/LVP10-65.pdf



So - not LiFePO4, not LMO either but LCO - the cathode type for the high 

energy density but with the bad reputation:

http://www.mpoweruk.com/lithium_failures.htm

(sorry about the graph without numbers or provenance).



I am still not sure whether in operation they do monitor each individual 

cell (volts, temperature?) before aggregating the result into a status 

for a whole series chain. The 787 APU starter battery uses 8 cells in 

series for 32 V no-load (nominal cell voltage 3.7 V vs. about 3.2 V for 

LiFePO4).



Jan de Jong

rlborger(at)mac.com
Guest

Posted: Wed Jan 16, 2013 4:36 pm Post subject: Lithium batteries redux

Gents,



With the Boeing 787 Dreamliner being grounded till their Li batteries can be checked, I figure it's a good time to report on my new AeroVoltz LiFePo battery.



I said that I'd report on any testing I did on the AeroVoltz battery.  Today I turned on the master which powered up the, Turbo Control Unit (Rotax 914), the GRT EIS4000 Engine Information System and the Airmaster AC200 prop controller.  I then turned on the MicroAir 760 Comm radio and MicroAir T2000 transponder.  With the comm radio tuned between ASOS, Ground Control & Tower (I swapped between them) and the transponder set on ALT DISPLAY (so the encoder was fired up as well), the voltage started at 12.4 Volts.  It took almost exactly 20 minutes for the voltage to sag down to 11 Volts.  When the voltage went to 10.9 Volts, I terminated the test and put the battery on cell balance charge.



So there you have it.  20 minutes on what I would consider the minimum load.  If for any reason I needed to be in the air longer than that to make it to the closest airport and that airport had a tower, I would probably shut down the radio and, maybe, the transponder till they were needed.  Maybe even pull the breaker on the prop controller till needed.  That would leave the only load as the EIS and TCU which should extend the battery life further.



Blue skies & tailwinds,

Bob Borger

Europa XS Tri, Rotax 914, Airmaster C/S Prop.

Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

3705 Lynchburg Dr.

Corinth, TX  76208-5331

Cel: 817-992-1117

rlborger(at)mac.com



On Jan 8, 2013, at 4:20 PM, Robert Borger <rlborger(at)mac.com> wrote:



Bob,



You may very well be correct, but I've gone out on a limb that I trust will support me and the aircraft.



I have purchased and installed an Aerovoltz 12 Cell EV02 LiFePo battery in my Europa.  The LiFePo battery is not supposed to be the fire hazard that the LiFe battery is.  It is amazingly small and light.  About 12 lbs lighter than the Odyssey it replaces.



I would not have done this had my Rotax 914 still been electric dependent with two electric fuel pumps.  about 2 years ago I replaced one of the electric pumps with an engine driven, mechanical pump so the engine will continue to operate should the electrics go totally dead.



So far, in 2 hours of testing on the ground and 1 hour in the air, all seems well.  It spins the Rotax on startup just like the Odyessy.  I purchased the special charger that will do fast, 5A, charge; slow. 2A, charge; maintenance, .1A, charge/float and cell balancing.  I have not done any time/power testing.  I need to see how long it will run the radio, transponder and GRT EIS 4000 and then test with only the radio and EIS.  When this is done, I will report the results.  



The seller of the battery did warn not to discharge below 9v as that would probably permanently damage the battery.  And if discharged to below 11 volts, it must be recharged in the cell balance mode.  



Isn't this one reason why we call it Experimental?

jan_de_jong(at)casema.nl
Guest

Posted: Thu Jan 17, 2013 3:09 am Post subject: Lithium batteries redux

Robert,



This is a disappointing endurance..

The battery is advertised as 20 PbEq Ah - a meaningless number 

introduced by Shorai for marketing reasons.

The actual maximum energy content should be about 6.5 Ah (Shorai applied 

a factor 3, Aerovoltz/Ballistic probably do the same).

At a 1 to 2C discharge rate from 12.4 (under load) to 11 V you should 

get about 90% of that out of a fully charged battery.

That is 60 minutes at 6 A, 40 minutes at 9 A, 30 minutes at 12 A.

I would have expected at least twice as long as 20 minutes...



Jan de Jong



On 1/17/2013 1:35 AM, Robert Borger wrote:

 	  Quote: 	
		   



 Gents,



 With the Boeing 787 Dreamliner being grounded till their Li batteries can be checked, I figure it's a good time to report on my new AeroVoltz LiFePo battery.



 I said that I'd report on any testing I did on the AeroVoltz battery.  Today I turned on the master which powered up the, Turbo Control Unit (Rotax 914), the GRT EIS4000 Engine Information System and the Airmaster AC200 prop controller.  I then turned on the MicroAir 760 Comm radio and MicroAir T2000 transponder.  With the comm radio tuned between ASOS, Ground Control & Tower (I swapped between them) and the transponder set on ALT DISPLAY (so the encoder was fired up as well), the voltage started at 12.4 Volts.  It took almost exactly 20 minutes for the voltage to sag down to 11 Volts.  When the voltage went to 10.9 Volts, I terminated the test and put the battery on cell balance charge.



 So there you have it.  20 minutes on what I would consider the minimum load.  If for any reason I needed to be in the air longer than that to make it to the closest airport and that airport had a tower, I would probably shut down the radio and, maybe, the transponder till they were needed.  Maybe even pull the breaker on the prop controller till needed.  That would leave the only load as the EIS and TCU which should extend the battery life further.



 Blue skies & tailwinds,

 Bob Borger

 Europa XS Tri, Rotax 914, Airmaster C/S Prop.

 Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

 3705 Lynchburg Dr.

 Corinth, TX  76208-5331

 Cel: 817-992-1117

 rlborger(at)mac.com



 On Jan 8, 2013, at 4:20 PM, Robert Borger <rlborger(at)mac.com> wrote:



 Bob,



 You may very well be correct, but I've gone out on a limb that I trust will support me and the aircraft.



 I have purchased and installed an Aerovoltz 12 Cell EV02 LiFePo battery in my Europa.  The LiFePo battery is not supposed to be the fire hazard that the LiFe battery is.  It is amazingly small and light.  About 12 lbs lighter than the Odyssey it replaces.



 I would not have done this had my Rotax 914 still been electric dependent with two electric fuel pumps.  about 2 years ago I replaced one of the electric pumps with an engine driven, mechanical pump so the engine will continue to operate should the electrics go totally dead.



 So far, in 2 hours of testing on the ground and 1 hour in the air, all seems well.  It spins the Rotax on startup just like the Odyessy.  I purchased the special charger that will do fast, 5A, charge; slow. 2A, charge; maintenance, .1A, charge/float and cell balancing.  I have not done any time/power testing.  I need to see how long it will run the radio, transponder and GRT EIS 4000 and then test with only the radio and EIS.  When this is done, I will report the results.



 The seller of the battery did warn not to discharge below 9v as that would probably permanently damage the battery.  And if discharged to below 11 volts, it must be recharged in the cell balance mode.



 Isn't this one reason why we call it Experimental?

rlborger(at)mac.com
Guest

Posted: Thu Jan 17, 2013 5:37 am Post subject: Lithium batteries redux

Jan,



I agree.  It is disappointing.  I had hoped for at least 30 minutes on the tested load.



The battery works fine for cranking the engine but does not have the endurance I would have liked under a small load.  I don't think there is any way this battery would work for an electrically dependent aircraft.



Blue skies & tailwinds,

Bob Borger

Europa XS Tri, Rotax 914, Airmaster C/S Prop.

Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

3705 Lynchburg Dr.

Corinth, TX  76208-5331

Cel: 817-992-1117

rlborger(at)mac.com



On Jan 17, 2013, at 5:06 AM, Jan de Jong <jan_de_jong(at)casema.nl> wrote:






Robert,



This is a disappointing endurance..

The battery is advertised as 20 PbEq Ah - a meaningless number introduced by Shorai for marketing reasons.

The actual maximum energy content should be about 6.5 Ah (Shorai applied a factor 3, Aerovoltz/Ballistic probably do the same).

At a 1 to 2C discharge rate from 12.4 (under load) to 11 V you should get about 90% of that out of a fully charged battery.

That is 60 minutes at 6 A, 40 minutes at 9 A, 30 minutes at 12 A.

I would have expected at least twice as long as 20 minutes...



Jan de Jong



On 1/17/2013 1:35 AM, Robert Borger wrote:

 	  Quote: 	
		   

 

 Gents,

 

 With the Boeing 787 Dreamliner being grounded till their Li batteries can be checked, I figure it's a good time to report on my new AeroVoltz LiFePo battery.

 

 I said that I'd report on any testing I did on the AeroVoltz battery.  Today I turned on the master which powered up the, Turbo Control Unit (Rotax 914), the GRT EIS4000 Engine Information System and the Airmaster AC200 prop controller.  I then turned on the MicroAir 760 Comm radio and MicroAir T2000 transponder.  With the comm radio tuned between ASOS, Ground Control & Tower (I swapped between them) and the transponder set on ALT DISPLAY (so the encoder was fired up as well), the voltage started at 12.4 Volts.  It took almost exactly 20 minutes for the voltage to sag down to 11 Volts.  When the voltage went to 10.9 Volts, I terminated the test and put the battery on cell balance charge.

 

 So there you have it.  20 minutes on what I would consider the minimum load.  If for any reason I needed to be in the air longer than that to make it to the closest airport and that airport had a tower, I would probably shut down the radio and, maybe, the transponder till they were needed.  Maybe even pull the breaker on the prop controller till needed.  That would leave the only load as the EIS and TCU which should extend the battery life further.

 

 Blue skies & tailwinds,

 Bob Borger

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jan 17, 2013 7:50 am Post subject: Lithium batteries redux

At 07:35 AM 1/17/2013, you wrote:

 	  Quote: 	
		  



Jan,



I agree.  It is disappointing.  I had hoped for at least 30 minutes 

on the tested load.



The battery works fine for cranking the engine but does not have the 

endurance I would have liked under a small load.  I don't think 

there is any way this battery would work for an electrically 

dependent aircraft.


	


   Are there any data packages available for these

   batteries? Discharge curves, engineering data?



   Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Thu Jan 17, 2013 9:05 am Post subject: Lithium batteries redux

Not that I know.

But, FWIW, I believe the Ballistic and Aerovoltz batteries (among other) 

are constituted from A123 ANR26650 cells:

http://www.a123systems.com/Collateral/Documents/English-US/A123%20Systems%20ANR26650%20Data%20Sheet.pdf

The 12 cell item (4 x 3) should then have capacity of at least 7.2 Ah 

and internal resistance of 8 mOhm.

Discharge voltage degradation at low temperatures to be noted.



Jan de Jong



On 1/17/2013 4:48 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   

 <nuckolls.bob(at)aeroelectric.com>



 At 07:35 AM 1/17/2013, you wrote:

> 

> <rlborger(at)mac.com>

>

> Jan,

>

> I agree.  It is disappointing.  I had hoped for at least 30 minutes 

> on the tested load.

>

> The battery works fine for cranking the engine but does not have the 

> endurance I would have liked under a small load.  I don't think there 

> is any way this battery would work for an electrically dependent 

> aircraft.



   Are there any data packages available for these

   batteries? Discharge curves, engineering data?



   Bob . . .

mmayfield

Joined: 09 Oct 2009
Posts: 40
Location: NSW Central Coast, Australia

Posted: Sun Jan 20, 2013 12:20 am Post subject: Re: Lithium batteries redux

I have to sympathise with Bob's views here.



Lithium-chemistry based batteries hold a lot of promise for aircraft power sources, but there are clearly issues to be resolved, not least of which is the possibility of a battery fire. I know the problems will eventually be solved, but until that time, I have to question whether the risk is worth taking.



There's a limit to how far I'm willing to push the "experimental" aspect!

_________________
Mike

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