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nuckolls.bob(at)aeroelect
Guest

Posted: Wed Nov 05, 2014 11:58 am Post subject: lithium facts

 	  Quote: 	
		  

Math check!  24/300 = 8%... but 2% is 10's complement, for what 

that's worth (my mind works that way, at least...)



Paul


	


    Good catch! I was mousing it out on the uSoft

    Windows calculator . . . which has problematic

    ergonomics . . . especially for ol' farts.



    An eye-ball check would have raised the flag . . .

   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Nov 05, 2014 12:15 pm Post subject: lithium facts

At 12:46 2014-11-05, you wrote:

 	  Quote: 	
		  



Well, all I can say - I'm amazed.

I wonder why I never read anything anywhere but 3.6V to 3.7V - with 

dire warnings about exceeding much...


	


   I suspect the 3.7 figure is the supplier's

   safe-haven. You can't hurt the cell by limiting

   to this value as demonstrated by countless examples

   of 4-cell stacks in vehicular DC power systems.



   I've got some 'wall-wart' single-cell chargers

   I'm going to study in detail . . .



   I note that these chargers are supplied in both

   3.7v  . . .

http://tinyurl.com/nr8m5t8

   and 4.2 volt . . .



http://tinyurl.com/nu55dth



   . . .  versions but without explanation as to

   the difference . . .



   Here's one add that speaks to 3.7/4.2 volts in

   one breath . . .



http://tinyurl.com/opmcjb9



   but in the fine print, we see that they claim

   a 4.2 volt output for cells spec'd in the 3.6

   to 4.2 range. I read this to mean that they're

   going to charge your battery to a 4.2 volt endpoint

   irrespective of how it was 'rated'.

 	  Quote: 	
		  By the way, these people show 90% charge at 3.6V (100% at 4.2V):

http://www.powerstream.com/LLLF.htm


	


   Interesting link. Thanks!

   I'll have to study it a bit . . .



   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Nov 05, 2014 12:23 pm Post subject: lithium facts

At 12:46 2014-11-05, you wrote:

 	  Quote: 	
		  



Well, all I can say - I'm amazed.

I wonder why I never read anything anywhere but 3.6V to 3.7V - with 

dire warnings about exceeding much...



By the way, these people show 90% charge at 3.6V (100% at 4.2V):

http://www.powerstream.com/LLLF.htm


	


   Check out this page . . .



http://tinyurl.com/2349lq2



   and the links cited thereon. Isidor Buchmann is

   about as knowledgeable as they come about batteries

   exceeded only by his generosity for sharing what

   he knows.

   Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Thu Nov 06, 2014 3:29 am Post subject: lithium facts

On 11/5/2014 9:22 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   

 <nuckolls.bob(at)aeroelectric.com>



 At 12:46 2014-11-05, you wrote:

> 

> <jan_de_jong(at)casema.nl>

>

> Well, all I can say - I'm amazed.

> I wonder why I never read anything anywhere but 3.6V to 3.7V - with 

> dire warnings about exceeding much...

>

> By the way, these people show 90% charge at 3.6V (100% at 4.2V):

> http://www.powerstream.com/LLLF.htm



   Check out this page . . .



 http://tinyurl.com/2349lq2



   and the links cited thereon. Isidor Buchmann is

   about as knowledgeable as they come about batteries

   exceeded only by his generosity for sharing what

   he knows.

   Bob . . .



Interesting.
	




It remains difficult to know when generic "Li-ion" data applies and when 

specific data is needed for one of the cathode chemistries: "LCO", 

"LMO", "LFP", "NMC", "NCA", "LTO"

see

http://batteryuniversity.com/learn/article/types_of_lithium_ion

http://batteryuniversity.com/learn/article/lithium_based_batteries



What I am guessing at the moment:



- the aging mechanisms and lifetime statistics are similar

   but some are more robust than others



- the maximum cell voltage (4.2V) applies to all



- charging method and charging phases are similar

   but they have different capacity vs. final charging voltage curves

   charging LFP beyond 3.6V doesn't add much, charging LCO beyond 3.8V 

to 4.2V adds most of the charge

   see http://www.powerstream.com/lithuim-ion-charge-voltage.htm

(the average force required to get an ion into a crystal location is 

different)



- they have different (slow) discharge voltage curves (LFP flat at about 

3.2V, LCO steadily decreasing from 3.9V)



I could be wrong.



Jan de Jong

jimkale(at)roadrunner.com
Guest

Posted: Fri Nov 07, 2014 11:18 pm Post subject: lithium facts

I have been studying lithium batteries for several years, when and where I

can find information.  I am not a chemist, or electrical battery engineer.

Just a guy who uses lots of lithium batteries.  I use them to power large

radio control models aircraft.  Common RC models these days use batteries

similar to the type you would use in a homebuilt airplane.  The RC models I

fly typically use 4 cell, 14.4 nominal volt batteries.  They are discharged

at the rate of about 30 to 150 amps and get totally drained in about 10

minutes.  Us modelers have also found that stopping the discharge at about

20 to 30 percent capacity remaining helps keep the cells cool and increases

their life substantially.



I have seen some lithium batteries catch fire in flight and the RC model

(normally fairly expensive - a few hundred dollars and normally built from

wood or plastic) goes down in flames.

  

All of the multi cell lithium batteries I use are charged with each cell in

the battery pack getting charged individually from a very special charger

normally called a balancing charger.  That means if you have 4 cells, there

are 5 wires coming from a balancing charger that independently charges and

monitors each cell while it is charging.   I believe that some of the high

end lithium batteries in use today have some balancing technology built into

each cell and these special batteries may be charged form a common source

like an alternator, with a single total charge voltage, sort of like the

lead acid battery charging we are all familiar with .  Inside each cell or

these special lithium batteries, the automatic circuitry keeps each

individual cell at a controlled charge current and the proper float voltage

when the cell is topped off at the proper voltage for the chemistry being

used.   All of this automatic control inside each cell, just means there are

many potential failure points.  If any individual cell, or its automatic

charge circuitry goes bad, the whole battery may fail in a mild manor (just

quits working) or catastrophic manor (fire).



All of this automatic cell monitoring is very expensive.   Failures may be

dangerous, or just very expensive.



The bottom line is if you want to switch to lithium batteries, you should

have your charge system designed by some highly qualified folks.  Just

buying and installing a lithium battery can be very expensive at best, or

very dangerous at worst.  Let the home builder beware.  You can bet Boeing

spent some very large sums of money for that lithium battery that caught

fire in their 787 Dreamliner.  Catastrophic failure is always possible no

matter how much you spend for hardware.



I work as a flight training systems instructor for a USAF squadron that

flies helicopters.   For the past 50 years or so, the military forces used

Nickel Cadmium batteries in their aircraft.  These batteries costs about 8

times as much as lead acid batteries, and required many man hours of service

and tests every 4 months.  Recently we switched to sealed lead acid

batteries (Gel Cells).  Now we pay about 5 times less than the NICADs costs,

and they don't need any regular maintenance.  We just use them till they

don't come up to standards, and replace them.  Much like you maintain your

car.  A giant leap backwards, and we save lots of money and get better

reliability and performance, not to mention improved safety (those NICADs

had a tendency to melt down every now and then.)  It doesn't get much better

than that.  Of course, the quality and performance of sealed lead acid

batteries has improved by leaps and bounds over the last 50 years.



Jim Kale



--

henador_titzoff(at)yahoo.
Guest

Posted: Sat Nov 08, 2014 5:35 am Post subject: lithium facts

Jim,

You sound like a man of real world experience with the batteries mentioned below. I'm guessing the following:



Much of your RC model airplane experience with lithium batteries is based on what you've been doing in the military world
You and your military friends have been exposed to more information about lithium battery testing than us civilians have, especially as applied to aviation.
This is probably why your military friends have not converted to lithium; instead, they went SVLA.

The lithium data that Bob N. is testing for has probably already been generated and reported but is proprietary and/or classified.I'm also speculating the reason Boeing has had bad luck with lithium batteries in their Dreamliner is they either didn't do enough testing, or the naysayers were overridden by the politicians who wanted to cut  weight everywhere. Throw out  a piece of failed test data here and there, and you're good to go thinking. They were probably in a hurry to leap frog the Frogs and Airbus. All speculation, mind you.

I could be wrong about all this, but it's my hunch.





Henador Titzoff

[quote]        From: Jim Kale <jimkale(at)roadrunner.com>

 To: aeroelectric-list(at)matronics.com  

 Sent: Saturday, November 8, 2014 2:16 AM

 Subject: RE: lithium facts

  

 

--> AeroElectric-List message posted by: "Jim Kale" <jimkale(at)roadrunner.com (jimkale(at)roadrunner.com)>



I have been studying lithium batteries for several years, when and where I

can find information.  I am not a chemist, or electrical battery engineer.

Just a guy who uses lots of lithium batteries.  I use them to power large

radio control models aircraft.  Common RC models these days use batteries

similar to the type you would use in a homebuilt airplane.  The RC models I

fly typically use 4 cell, 14.4 nominal volt batteries.  They are discharged

at the rate of about 30 to 150 amps and get totally  drained in about 10

minutes.  Us modelers have also found that stopping the discharge at about

20 to 30 percent capacity remaining helps keep the cells cool and increases

their life substantially.



I have seen some lithium batteries catch fire in flight and the RC model

(normally fairly expensive - a few hundred dollars and normally built from

wood or plastic) goes down in flames.

  

All of the multi cell lithium batteries I use are charged with each cell in

the battery pack getting charged individually from a very special charger

normally called a balancing charger.  That means if you have 4 cells, there

are 5 wires coming from a balancing charger that independently charges and

monitors each cell while it is charging.   I believe that some of the high

end lithium batteries in use today have some balancing technology built into

each cell and these special batteries may be charged form a  common source

like an alternator, with a single total charge voltage, sort of like the

lead acid battery charging we are all familiar with .  Inside each cell or

these special lithium batteries, the automatic circuitry keeps each

individual cell at a controlled charge current and the proper float voltage

when the cell is topped off at the proper voltage for the chemistry being

used.   All of this automatic control inside each cell, just means there are

many potential failure points.  If any individual cell, or its automatic

charge circuitry goes bad, the whole battery may fail in a mild manor (just

quits working) or catastrophic manor (fire).



All of this automatic cell monitoring is very expensive.   Failures may be

dangerous, or just very expensive.



The bottom line is if you want to switch to lithium batteries, you should

have your charge system designed by some highly qualified  folks.  Just

buying and installing a lithium battery can be very expensive at best, or

very dangerous at worst.  Let the home builder beware.  You can bet Boeing

spent some very large sums of money for that lithium battery that caught

fire in their 787 Dreamliner.  Catastrophic failure is always possible no

matter how much you spend for hardware.



I work as a flight training systems instructor for a USAF squadron that

flies helicopters.   For the past 50 years or so, the military forces used

Nickel Cadmium batteries in their aircraft.  These batteries costs about 8

times as much as lead acid batteries, and required many man hours of service

and tests every 4 months.  Recently we switched to sealed lead acid

batteries (Gel Cells).  Now we pay about 5 times less than the NICADs costs,

and they don't need any regular maintenance.  We just use them till they

don't come up  to standards, and replace them.  Much like you maintain your

car.  A giant leap backwards, and we save lots of money and get better

reliability and performance, not to mention improved safety (those NICADs

had a tendency to melt down every now and then.)  It doesn't get much better

than that.  Of course, the quality and performance of sealed lead acid

batteries has improved by leaps and bounds over the last 50 years.



Jim Kale



--

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Nov 08, 2014 8:25 am Post subject: lithium facts

At 07:31 2014-11-08, you wrote:

The lithium data that Bob N. is testing for has probably already been 

generated and reported but is proprietary and/or classified.

   I doubt it. Given the ease with which I have acquired

   more knowledge demonstrates that the data is not the

   the least bit 'secret'. Simple-ideas I've discovered

   for myself are alluded if not specifically addressed

   in Isador Buccmann's missives cited earlier.



   I think it a certainty that any supplier who fails to included

   'my' discoveries in their promotional/disclosure literature

   are either ignorant of such information, don't see

   why their customer would have an interest in such

   esoteric knowledge or they're not eager to reveal

   information that is counter-productive to a marketing

   effort.



   I'm reluctant to believe that anything is being deliberately

   withheld for dishonorable reasons . . . there's more

   tort lawyers per capita in the US than in any other

   nation. Perfectly honorable suppliers are already at

   considerable risk from this source of cultural misery . . .

   deliberate obfuscation of hazards by any suppler

   puts them at 1000x the risk.



I'm also speculating the reason Boeing has had bad luck with lithium 

batteries in their Dreamliner is they either didn't do enough 

testing, or the naysayers were overridden by the politicians who 

wanted to cut weight everywhere. Throw out  a piece of failed test 

data here and there, and you're good to go thinking. They were 

probably in a hurry to leap frog the Frogs and Airbus. All 

speculation, mind you.



   I think the Boeing story is exceedingly complicated and

   yes, fraught with some unhappy trade-offs. The testing

   was extensive but went mostly toward the notion of

   assessing risk based on failure rates which in turn

   were based on things not known to be poor assumptions.



   This is why my teachers encouraged me to assume the

   worst - assume a failure rate of 1 per flight hour

   then mitigate the risks of that failure. This is

   the approach ultimately adopted by Boeing and friends.

   It's the approach adopted by True Blue and has become

   the regulatory modus operandi as well.



   The BIG difference between the Boeing experience and

   the OBAM (or True Blue) experience is chemistry. The

   products of intense interest to us exploit LiFePO couples

   common to what now must be billions of examples ranging

   from the tiniest of consumer electro-whizzies up to

   the hybrid automobiles. The Tesla uses THOUSANDS of

   AA sized, LiFePO cells in parallel. The True Blue

   is a similarly complex array of cylindrical cells

   produced in the millions per week.



   I'll respond to Jim's generous sharing of experience

   and insights in depth . . . but right now, there are

   two car-loads of children and grand-children on their

   way to M.L. help grandma and grandpa take down a

   dying tree . . . and trim up some others.

   Bob . . .

henador_titzoff(at)yahoo.
Guest

Posted: Sat Nov 08, 2014 9:07 am Post subject: lithium facts

This is rather unusual, Bob, that you responded to my email to the AE list, yet my two previous emails have not made it to the list. If you are filtering my emails to the list, then it's okay with me, but you've never told me why you are filtering them.  If you want me off your list, why not simply take me off the email roster?



 

Henador Titzoff

[quote]        From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

 To: aeroelectric-list(at)matronics.com 

 Sent: Saturday, November 8, 2014 11:25 AM

 Subject: Re: lithium facts

  

 

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>



At 07:31 2014-11-08, you wrote:

The lithium data that Bob N. is testing for has probably already been 

generated and reported but is proprietary and/or classified.

   I doubt it. Given the ease with which I have acquired

    more knowledge demonstrates that the data is not the

   the least bit 'secret'. Simple-ideas I've discovered

   for myself are alluded if not specifically addressed

   in Isador Buccmann's missives cited earlier.



   I think it a certainty that any supplier who fails to included

   'my' discoveries in their promotional/disclosure literature

   are either ignorant of such information, don't see

   why their customer would have an interest in such

   esoteric knowledge or they're not eager to reveal

   information that is counter-productive to a marketing

   effort.



   I'm reluctant to believe that anything is being deliberately

   withheld for dishonorable reasons . . . there's more

   tort lawyers per capita in the US than in any other

   nation. Perfectly honorable suppliers are already at

   considerable risk from this source  of cultural misery . . .

   deliberate obfuscation of hazards by any suppler

   puts them at 1000x the risk.



I'm also speculating the reason Boeing has had bad luck with lithium 

batteries in their Dreamliner is they either didn't do enough 

testing, or the naysayers were overridden by the politicians who 

wanted to cut weight everywhere. Throw out  a piece of failed test 

data here and there, and you're good to go thinking. They were 

probably in a hurry to leap frog the Frogs and Airbus. All 

speculation, mind you.



   I think the Boeing story is exceedingly complicated and

   yes, fraught with some unhappy trade-offs. The testing

   was extensive but went mostly toward the notion of

   assessing risk based on failure rates which in turn

   were based on things not known to be poor assumptions.



   This is why my teachers encouraged me to assume  the

   worst - assume a failure rate of 1 per flight hour

   then mitigate the risks of that failure. This is

   the approach ultimately adopted by Boeing and friends.

   It's the approach adopted by True Blue and has become

   the regulatory modus operandi as well.



   The BIG difference between the Boeing experience and

   the OBAM (or True Blue) experience is chemistry. The

   products of intense interest to us exploit LiFePO couples

   common to what now must be billions of examples ranging

   from the tiniest of consumer electro-whizzies up to

   the hybrid automobiles. The Tesla uses THOUSANDS of

   AA sized, LiFePO cells in parallel. The True Blue

   is a similarly complex array of cylindrical cells

   produced in the millions per week.



   I'll respond to Jim's generous sharing of experience

   and insights in [quote][b]

lyleapgmc

Joined: 19 Feb 2014
Posts: 57

Posted: Sat Nov 08, 2014 11:28 am Post subject: lithium facts

I have been looking at lithium battery packs and       find there is a wide variation in the per-cell voltage.  Some are       as low as 1.2V and up to 1.8V and 3.7V.  The discussion here       indicates that 3.7V is the standard for lithium cells.  

       

       Were there or are there lithium cells of lower voltage?

          [quote]-- 

Lyle



Sent from my Gateway E4610D desktop



[b]

Mauledriver(at)nc.rr.com
Guest

Posted: Sat Nov 08, 2014 11:53 am Post subject: lithium facts

On 11/8/2014 8:31 AM, Henador Titzoff       wrote:

     

      	  Quote: 	
		                  Jim,

         

           

         You sound like a man of real world             experience with the batteries mentioned below. I'm guessing             the following:

                    Much of your               RC model airplane experience with lithium batteries is               based on what you've been doing in the military world                

     	
     I would guess not.  Rather that the RC model community is, and has     been, deep into lithium battery technology for some time.  Perhaps     leaders in the field, at least from an OBAM standpoint.  My brother     has been in RC competitively for decades. As many other have, he has     converted 100% to lithium (probably LiPo) battery power for his     competition aircraft.  They buy them, use them, abuse them, measure     them and fail them.  I'm sure there's a wealth of real world     experience AND DATA there, but I have no idea whether it would be     useful in our environment.

     [quote]                           You and your               military friends have been exposed to more information               about lithium battery testing than us civilians have,               especially as applied to aviation.           
This is               probably why your military friends have not converted to               lithium; instead, they went SVLA.

                      
The lithium               data that Bob N. is testing for has probably already been               generated and reported but is proprietary and/or               classified.                  I'm also speculating the reason Boeing has had bad luck           with lithium batteries in their Dreamliner is they either           didn't do enough testing, or the naysayers were overridden by           the politicians who wanted to cut weight everywhere. Throw out            a piece of failed test data here and there, and you're good           to go thinking. They were probably in a hurry to leap frog the           Frogs and Airbus. All speculation, mind you.

         

         

         I could be wrong about all this, but it's my hunch.

         

         

         Henador Titzoff

         

         

          	  Quote: 	
		                                                            From: Jim                   Kale <jimkale(at)roadrunner.com> (jimkale(at)roadrunner.com)

                   To:                   aeroelectric-list(at)matronics.com (aeroelectric-list(at)matronics.com) 

                   Sent:                   Saturday, November 8, 2014 2:16 AM

                   Subject:                   RE: lithium facts

                  

               

                 --> AeroElectric-List message posted by: "Jim Kale"                 <jimkale(at)roadrunner.com (jimkale(at)roadrunner.com)>

                 

                 I have been studying lithium batteries for several                 years, when and where I

                 can find information.  I am not a chemist, or electrical                 battery engineer.

                 Just a guy who uses lots of lithium batteries.  I use                 them to power large

                 radio control models aircraft.  Common RC models these                 days use batteries

                 similar to the type you would use in a homebuilt                 airplane.  The RC models I

                 fly typically use 4 cell, 14.4 nominal volt batteries.                  They are discharged

                 at the rate of about 30 to 150 amps and get totally                 drained in about 10

                 minutes.  Us modelers have also found that stopping the                 discharge at about

                 20 to 30 percent capacity remaining helps keep the cells                 cool and increases

                 their life substantially.

                 

                 I have seen some lithium batteries catch fire in flight                 and the RC model

                 (normally fairly expensive - a few hundred dollars and                 normally built from

                 wood or plastic) goes down in flames.

                   

                 All of the multi cell lithium batteries I use are                 charged with each cell in

                 the battery pack getting charged individually from a                 very special charger

                 normally called a balancing charger.  That means if you                 have 4 cells, there

                 are 5 wires coming from a balancing charger that                 independently charges and

                 monitors each cell while it is charging.  I believe that                 some of the high

                 end lithium batteries in use today have some balancing                 technology built into

                 each cell and these special batteries may be charged                 form a common source

                 like an alternator, with a single total charge voltage,                 sort of like the

                 lead acid battery charging we are all familiar with .                  Inside each cell or

                 these special lithium batteries, the automatic circuitry                 keeps each

                 individual cell at a controlled charge current and the                 proper float voltage

                 when the cell is topped off at the proper voltage for                 the chemistry being

                 used.  All of this automatic control inside each cell,                 just means there are

                 many potential failure points.  If any individual cell,                 or its automatic

                 charge circuitry goes bad, the whole battery may fail in                 a mild manor (just

                 quits working) or catastrophic manor (fire).

                 

                 All of this automatic cell monitoring is very                 expensive.  Failures may be

                 dangerous, or just very expensive.

                 

                 The bottom line is if you want to switch to lithium                 batteries, you should

                 have your charge system designed by some highly                 qualified folks.  Just

                 buying and installing a lithium battery can be very                 expensive at best, or

                 very dangerous at worst.  Let the home builder beware.                  You can bet Boeing

                 spent some very large sums of money for that lithium                 battery that caught

                 fire in their 787 Dreamliner.  Catastrophic failure is                 always possible no

                 matter how much you spend for hardware.

                 

                 I work as a flight training systems instructor for a                 USAF squadron that

                 flies helicopters.  For the past 50 years or so, the                 military forces used

                 Nickel Cadmium batteries in their aircraft.  These                 batteries costs about 8

                 times as much as lead acid batteries, and required many                 man hours of service

                 and tests every 4 months.  Recently we switched to                 sealed lead acid

                 batteries (Gel Cells).  Now we pay about 5 times less                 than the NICADs costs,

                 and they don't need any regular maintenance.  We just                 use them till they

                 don't come up to standards, and replace them.  Much like                 you maintain your

                 car.  A giant leap backwards, and we save lots of money                 and get better

                 reliability and performance, not to mention improved                 safety (those NICADs

                 had a tendency to melt down every now and then.)  It                 doesn't get much better

                 than that.  Of course, the quality and performance of                 sealed lead acid

                 batteries has improved by leaps and bounds over the last                 50 years.

                 

                 Jim Kale

                 

               

             

           

         	
       

     [b]

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Nov 08, 2014 12:49 pm Post subject: lithium facts

At 11:03 2014-11-08, you wrote:

 	  Quote: 	
		  This is rather unusual, Bob, that you responded to my email to the 

AE list, yet my two previous emails have not made it to the list. If 

you are filtering my emails to the list, then it's okay with me, but 

you've never told me why you are filtering them.  If you want me off 

your list, why not simply take me off the email roster?



Henador Titzoff


	


   I have no ability nor inclination to 'filter' anyone.

   I've had to ask several individuals to quit the list

   over the years but I've not advocated for any form

   of 'firewall' against anyone.



   Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Sat Nov 08, 2014 12:50 pm Post subject: lithium facts

Tesla does not use LiFePO4, but something more energetic, I believe:

http://batteryuniversity.com/learn/article/safety_of_lithium_ion_batteries



 	  Quote: 	
		  

   The BIG difference between the Boeing experience and

   the OBAM (or True Blue) experience is chemistry. The

   products of intense interest to us exploit LiFePO couples

   common to what now must be billions of examples ranging

   from the tiniest of consumer electro-whizzies up to

   the hybrid automobiles. The Tesla uses THOUSANDS of

   AA sized, LiFePO cells in parallel. The True Blue

   is a similarly complex array of cylindrical cells

   produced in the millions per week.

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Nov 08, 2014 2:15 pm Post subject: lithium facts

At 14:48 2014-11-08, you wrote:

 	  Quote: 	
		  



Tesla does not use LiFePO4, but something more energetic, I believe:

http://batteryuniversity.com/learn/article/safety_of_lithium_ion_batteries


	


   here is one of several articles I see that prompted my

   assertion . . .



http://tinyurl.com/pqo59cr



   Bob . . .

raymondj(at)frontiernet.n
Guest

Posted: Sat Nov 08, 2014 2:36 pm Post subject: lithium facts

Greetings Mr. Titzoff,

I have been on this list for a number of years and have seen several 

glitches that resulted in my and other's emails not showing up. 

Sometimes it was something that the sender changed, sometimes it was a 

change made by the sender's ISP, and sometimes it was something Matt D. 

did.  I don't really have any helpful suggestions, just wanted to 

mention all the possible places where things can go awry.  If I can be 

of assistance in helping sort this out, please let me know.

do not archive

Raymond Julian

Kettle River, MN

The things we admire in men, kindness and generosity, openness, honesty, 

understanding and feeling are the concomitants of failure in our system. 

And those traits we detest, sharpness, greed, acquisitiveness, meanness, 

egotism and self-interest are the traits of success. And while men 

admire the quality of the first they love the produce of the second. 

-John Steinbeck, novelist, Nobel laureate (1902-1968)

On 11/08/2014 02:48 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	

 <nuckolls.bob(at)aeroelectric.com>

 At 11:03 2014-11-08, you wrote:

> This is rather unusual, Bob, that you responded to my email to the AE

> list, yet my two previous emails have not made it to the list. If you

> are filtering my emails to the list, then it's okay with me, but

> you've never told me why you are filtering them.  If you want me off

> your list, why not simply take me off the email roster?

>

> Henador Titzoff

    I have no ability nor inclination to 'filter' anyone.

    I've had to ask several individuals to quit the list

    over the years but I've not advocated for any form

    of 'firewall' against anyone.

    Bob . . .

henador_titzoff(at)yahoo.
Guest

Posted: Sat Nov 08, 2014 4:38 pm Post subject: lithium facts

Raymond,



I appreciate your offer to troubleshoot my problem, but I've already input a trouble ticket to my ISP.  Let me see what they have to say about this first, then I'll contact you if they or I don't resolve the problem.



Thank you very much.



 

do not archive



Henador Titzoff



[quote]        From: rayj <raymondj(at)frontiernet.net> To: aeroelectric-list(at)matronics.com  Sent: Saturday, November 8, 2014 5:34 PM Subject: Re: lithium facts  

 --> AeroElectric-List message posted by: rayj <raymondj(at)frontiernet.net (raymondj(at)frontiernet.net)>Greetings Mr. Titzoff,I have been on this list for a number of years and have seen several glitches that resulted in my and other's emails not showing up. Sometimes it was something that the sender changed, sometimes it was a change made by the sender's ISP, and sometimes it was something Matt D. did.  I don't really have any helpful suggestions, just wanted to mention all the possible places where things can go awry.  If I can be of assistance in helping sort this out, please let me know.do not archiveRaymond JulianKettle River, MNThe things we admire in men, kindness and generosity, openness, honesty, understanding and feeling are the concomitants of failure in our system. And those traits we detest, sharpness, greed, acquisitiveness, meanness, egotism and self-interest are the traits of success. And while men admire the quality of the first they love the produce of the second. -John Steinbeck, novelist, Nobel laureate (1902-1968)On 11/08/2014 02:48 PM, Robert L. Nuckolls, III wrote:> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"> <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>>> At 11:03 2014-11-08, you wrote:>> This is rather unusual, Bob, that you responded to my email to the AE>> list, yet my two previous emails have not made it to the list. If you>> are filtering my emails to the list, then it's okay with me, but>> you've never told me why you are filtering them.  If you want me off>> your list, why not simply take me off the email roster?>>>> Henador Titzoff>>    I have no ability nor inclination to 'filter' anyone.>    I've had to ask several individuals to quit the list

ceengland7(at)gmail.com
Guest

Posted: Sat Nov 08, 2014 6:47 pm Post subject: lithium facts

I would 2nd Raymond's observations.

Over the last 6 or 8 months, I've sent numerous emails to various 

unrelated lists (not all Matt's) that never appeared as an email from 

the list back to me, but have seen others' replies to those emails. When 

checking the archives, the original email appears there.

If you're saying that you didn't get your own email but saw a reply to 

it on the list, then it obviously went to the rest of the list, but 

wasn't returned to you by the (automated) list. Or, according to some 

googling, it might be related to your own ISP or email provider.

FWIW,

Charlie

On 11/8/2014 4:34 PM, rayj wrote:

 	  Quote: 	

 Greetings Mr. Titzoff,

 I have been on this list for a number of years and have seen several 

 glitches that resulted in my and other's emails not showing up. 

 Sometimes it was something that the sender changed, sometimes it was a 

 change made by the sender's ISP, and sometimes it was something Matt 

 D. did.  I don't really have any helpful suggestions, just wanted to 

 mention all the possible places where things can go awry.  If I can be 

 of assistance in helping sort this out, please let me know.

 do not archive

 Raymond Julian

 Kettle River, MN

 The things we admire in men, kindness and generosity, openness, 

 honesty, understanding and feeling are the concomitants of failure in 

 our system. And those traits we detest, sharpness, greed, 

 acquisitiveness, meanness, egotism and self-interest are the traits of 

 success. And while men admire the quality of the first they love the 

 produce of the second. -John Steinbeck, novelist, Nobel laureate 

 (1902-1968)

 On 11/08/2014 02:48 PM, Robert L. Nuckolls, III wrote:

> 

> <nuckolls.bob(at)aeroelectric.com>

>

> At 11:03 2014-11-08, you wrote:

>> This is rather unusual, Bob, that you responded to my email to the AE

>> list, yet my two previous emails have not made it to the list. If you

>> are filtering my emails to the list, then it's okay with me, but

>> you've never told me why you are filtering them.  If you want me off

>> your list, why not simply take me off the email roster?

>>

>> Henador Titzoff

>

>    I have no ability nor inclination to 'filter' anyone.

>    I've had to ask several individuals to quit the list

>    over the years but I've not advocated for any form

>    of 'firewall' against anyone.

>

>    Bob . . .

henador_titzoff(at)yahoo.
Guest

Posted: Sun Nov 09, 2014 3:50 am Post subject: lithium facts

Charlie,

I've read on this list of others having problems like what you describe below and have even seen the very same problem on two other lists, non-Matt related.  If it works for many and not for a few, then it has to be related to those few, including me.  When Bob wrote me back, it confirmed exactly what you describe below - something is wrong on  my end of the pipe. I'm actively checking it out and in fact, this email is a test email to see if a "fix" solves the problem. Yes, IT works on weekends, cause I have them on the Essential bus. 

do not archive

Henador Titzoff

[quote]         From: Charlie England <ceengland7(at)gmail.com>

 To: aeroelectric-list(at)matronics.com 

 Sent: Saturday, November 8, 2014 9:45 PM

 Subject: Re: lithium facts

--> AeroElectric-List message posted by: Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)>

I would 2nd Raymond's observations.

Over the last 6 or 8 months, I've sent numerous emails to various 

unrelated lists (not all Matt's) that never appeared as an email  from 

the list back to me, but have seen others' replies to those emails. When 

checking the archives, the original email appears there.

If you're saying that you didn't get your own email but saw a reply to 

it on the list, then it obviously went to the rest of the list, but 

wasn't returned to you by the (automated) list. Or, according to some 

googling, it might be related to your own ISP or email provider.

FWIW,

Charlie

On 11/8/2014 4:34 PM, rayj wrote:

[quote] --> AeroElectric-List message posted by: rayj <raymondj(at)frontiernet.net (raymondj(at)frontiernet.net)>

 Greetings Mr. Titzoff,

 I have been on this list for a number of years and have seen several 

 glitches that resulted in my and other's emails not showing up. 

 Sometimes it was something that the sender changed, sometimes it was a  

 change made by the sender's ISP, and sometimes it was something Matt 

 D. did.  I don't really have any helpful suggestions, just wanted to 

 mention all the possible places where things can go awry.  If I can be 

 of assistance in helping sort this out, please let me know.

 do not archive

 Raymond Julian

 Kettle River, MN

 The things we admire in men, kindness and generosity, openness, 

 honesty, understanding and feeling are the concomitants of failure in 

 our system. And those traits we detest, sharpness, greed, 

 acquisitiveness, meanness, egotism and self-interest are the traits of 

 success. And while men admire the quality of the first they love the 

 produce of the second. -John Steinbeck, novelist, Nobel laureate 

 (1902-1968)

 On 11/08/2014 02:48 PM, Robert L. Nuckolls, III wrote:

>  --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"

> <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

>

> At 11:03 2014-11-08, you wrote:

>> This is rather unusual, Bob, that you responded to my email to the AE

>> list, yet my two previous emails have not made it to the list. If you

>> are filtering my emails to the list, then it's okay with me, but

>> you've never told me why you are filtering them.  If you want me off

>> your list, why not simply take me off the email roster?

>>

>> Henador Titzoff

>

>    I have no ability nor inclination to 'filter' anyone.

>    I've had to ask several individuals to quit the list

>    over the years but I've not [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Nov 09, 2014 9:06 am Post subject: lithium facts

At 01:16 2014-11-08, you wrote:

 --> AeroElectric-List message posted by: "Jim Kale" <jimkale(at)roadrunner.com>



 I have been studying lithium batteries for several years, when and where I

 can find information.  I am not a chemist, or electrical battery engineer.

 Just a guy who uses lots of lithium batteries.  I use them to power large

 radio control models aircraft.  Common RC models these days use batteries

 similar to the type you would use in a homebuilt airplane.  The RC models I

 fly typically use 4 cell, 14.4 nominal volt batteries.  They are discharged

 at the rate of about 30 to 150 amps and get totally drained in about 10

 minutes.  Us modelers have also found that stopping the discharge at about

 20 to 30 percent capacity remaining helps keep the cells cool and increases

 their life substantially.



    An excellent narrative illustrating a substantial difference   in the way the aviation community uses batteries.

 

    Unlike ALL motive power applications, the engine-crank/standby   applications use about 4% of the battery's capacity during   a few seconds per flight cycle . . . recharging is not expected   to complete in less than 30 minutes. But most important . . .   there are NO conditions under which our batteries are expected/   permitted to experience substantial temperature rise.

 

    I suggest that the only 'connection' between the motive   power applications (from model airplanes up to plug-n-drive   forklifts and cars) and virtually all crank-and-sit applications   (most cars, trucks, and airplanes) is the word 'lithium'.



 I have seen some lithium batteries catch fire in flight and the RC model

 (normally fairly expensive - a few hundred dollars and normally built from

 wood or plastic) goes down in flames.



    I'm pretty sure these were not lithium-iron phosphate cells.   However, it is certain that they were HIGHLY stressed    compared to aviation expectations/design goals.



   

 All of the multi cell lithium batteries I use are charged with each cell in

 the battery pack getting charged individually from a very special charger

 normally called a balancing charger. If any individual cell, or its automatic charge circuitry goes

 bad, the whole battery may fail in a mild manor (just quits working)

 or catastrophic manor (fire).



 All of this automatic cell monitoring is very expensive.   Failures may be

 dangerous, or just very expensive.



     To be sure, the battery management systems (BMS) included   as part of the qualified True Blue products adds significant cost   to the battery.  But be aware that "BMS" can mean anything   from a simple poly-fuse built into the end-cap of a cell   all the way up to a Cray-sized byte thrasher that monitors   cell voltage, input-output currents, temperatures, local   barometric pressure and phases of the moon.



 The bottom line is if you want to switch to lithium batteries, you should

 have your charge system designed by some highly qualified folks.  Just

 buying and installing a lithium battery can be very expensive at best, or

 very dangerous at worst.  Let the home builder beware.  You can bet Boeing

 spent some very large sums of money for that lithium battery that caught

 fire in their 787 Dreamliner.  Catastrophic failure is always possible no

 matter how much you spend for hardware.



  The Boeing experience has few more parallels to our design and risk reduction goals than motive power applications but they're not terribly germane. We can draw more on the lessons-learned by Cessna and True-Blue than upon anything that happened in a 787

  The manner in which we will use lithium will not stress the cells hard at all. We're only going to charge to 50-60% of the chemistry's potential. We only discharge to the tune of 4-5% per flight cycle at most . . . the give 30 minutes to replace that trivial taxation of store energy. Ideally, we NEVER deeply discharge the battery. A totally different world than what is expected of most lithium products in service today.

 



 I work as a flight training systems instructor for a USAF squadron that

 flies helicopters.   For the past 50 years or so, the military forces used

 Nickel Cadmium batteries in their aircraft.  These batteries costs about 8

 times as much as lead acid batteries, and required many man hours of service

 and tests every 4 months.  Recently we switched to sealed lead acid

 batteries (Gel Cells).  Now we pay about 5 times less than the NICADs costs,

 and they don't need any regular maintenance.  We just use them till they

 don't come up to standards, and replace them.  Much like you maintain your

 car.  A giant leap backwards, and we save lots of money and get better

 reliability and performance, not to mention improved safety (those NICADs

 had a tendency to melt down every now and then.)  It doesn't get much better

 than that.  Of course, the quality and performance of sealed lead acid

 batteries has improved by leaps and bounds over the last 50 years.



    Exactly. Your story has been repeated many times over   the years. Skip Koss at Concorde can recite a number   of instances were Concorde SVLA products have successfully   replaced Ni-Cad in military and air-transport applications   for much improved cost of ownership benefits.      The sealed lead-acid battery took cost of   ownership a quantum jump in the right direction. However,   my own limited studies into the lithium opportunities   suggest that 'going-lithium' just  to save weight while   giving up performance and risk benefits of SVLA may not   be justifiable in every owner-operator's play-book.

    Watch this space . . .



    Bob . . .



         [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Nov 09, 2014 4:52 pm Post subject: lithium facts

 	  Quote: 	
		  Interesting.



It remains difficult to know when generic "Li-ion" data applies and 

when specific data is needed for one of the cathode chemistries: 

"LCO", "LMO", "LFP", "NMC", "NCA", "LTO"

see


	


 	  Quote: 	
		  http://batteryuniversity.com/learn/article/types_of_lithium_ion

http://batteryuniversity.com/learn/article/lithium_based_batteries


	


    I note that in BU-204, the chart cites an LFP

    charge limit of 3.6 volts . . . which is contrary

    to the claims and practices of the market place

    offerings of LFP cells . . . and not in agreement

    with my tests either.



 	  Quote: 	
		  What I am guessing at the moment:



- the aging mechanisms and lifetime statistics are similar

   but some are more robust than others


	


    agreed



 	  Quote: 	
		  - the maximum cell voltage (4.2V) applies to all


	


    agreed . . . I've not seen any literature that

    argues with this with the exception noted above.



 	  Quote: 	
		  - charging method and charging phases are similar

   but they have different capacity vs. final charging voltage curves

   charging LFP beyond 3.6V doesn't add much


	


    How do you arrive at this? The cells that I'm

    testing demonstrate a doubling of stored energy

    by extending the charge beyond 3.6 volts. The

    fact remains that incorporating an array of 4-cell

    strings into lead-acid optimized power systems

    will indeed limit charge voltage to something on

    the order of 3.7 volts . . . and even if we COULD

    charge the cell to 100%, it seems unlikely we can

    always exploit that energy due to its elevated

    delivery voltage.



 	  Quote: 	
		    charging LCO beyond 3.8V to 4.2V adds most of the charge

   see http://www.powerstream.com/lithuim-ion-charge-voltage.htm

(the average force required to get an ion into a crystal location is 

different)


	


    May well be. Don't have any of those cells to test and

    besides, we really NEED the LPF characteristic that

    tolerates heave discharge values along with the

    lower levels of risk.

 	  Quote: 	
		  - they have different (slow) discharge voltage curves (LFP flat at 

about 3.2V, LCO steadily decreasing from 3.9V)


	


    Not sure that 'flatness' of discharge has any big

    significance in our applications. The battery-only

    loads in aircraft are functional from 15 down to 11

    volts (which is right at the recommended limit for

    discharging lithium in a 4-cell string).





   Bob . . .

jan_de_jong(at)casema.nl
Guest

Posted: Mon Nov 10, 2014 3:26 pm Post subject: lithium facts

Interesting article concerning LiFePO4 and dynamic behaviour:

http://epg.eng.ox.ac.uk/sites/default/files/Howey/HEVC_IET_Birkl_Howey.pdf



An equivalent circuit was developed for an A123 APR18650 cell with 3 

series elements:

a series resistance of a few tens of mOhm,

a time constant of a few seconds that resolves to a series resistance of 

few mOhm,

a time constant of a few tens of seconds that resolves to a series 

resistance of a few tens of mOhm

(there are extremes at high and low temperatures and high and low SOC)



Something to think about when designing a balancing algorithm.

A voltage observed a couple of seconds after the application of a shunt 

cannot be compared directly to that voltage before the shunt application.

Estimating the final voltage (from slope and value at two moments ) 

would take tens of seconds...



Something else I would want to hear about from a supplier of batteries 

with built-in BMS.



Jan de Jong

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