Today's Message Index:
----------------------
0. 12:44 AM - Please Make a Contribution to Support Your Lists... (Matt Dralle)
1. 07:57 AM - Re: lithium facts (Jan de Jong)
2. 08:43 AM - Re: lithium facts (Jeff Luckey)
3. 08:59 AM - Lithium facts (Ronald Cox)
4. 08:59 AM - Lithium facts (Ronald Cox)
5. 12:02 PM - Re: lithium facts (Jan de Jong)
6. 12:35 PM - Re: lithium facts (BobsV35B@aol.com)
7. 01:34 PM - Re: lithium facts (Robert L. Nuckolls, III)
8. 05:08 PM - Re: lithium facts (argoldman@aol.com)
9. 10:23 PM - Charging system problem - please help troubleshoot (Bill Reining)
Message 0
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Subject: | Please Make a Contribution to Support Your Lists... |
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Message 1
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Subject: | Re: lithium facts |
On 11/14/2014 4:27 AM, Jeff Luckey wrote:
> Suggest updating the weight calculations to include a steel battery
> box to contain a lipo fire.
>
Is this a little pessimistic?
Some old LiFePO4 on youtube, for those who have not looked there yet -
vandalism committed upon a Headway 38120 10Ah LiFePO4 cell:
http://www.youtube.com/watch?v=8IBapfB0Imo
http://www.youtube.com/watch?v=52h8IK0IdqI
http://www.youtube.com/watch?v=wkJM8MZkFKU
Are the results valid for A123 ANR26650M1-B cells?
- on the one hand the Headway cell has a lower maximum discharge rate
(10C vs. 30C)
- and is slightly (8% or so) heavier per Ah
- on the other hand the state of charge ranges from fully charged to
very much overcharged
It does not appear as if a fire must be expected in the course of
reasonable or even unreasonable use.
Jan de Jong
Message 2
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Subject: | Re: lithium facts |
Jan,
I don't think I'm being pessimistic; cautious is a better word.
I have witnessed several lipo fires or their aftermath in R/C aircraft. I even
remember a Toyota Corolla that burned to the tires because of a Lipo that was
being charged in the back seat.
In addition, we all know about the Boeing issues. How many dollars did they spend
on R&D?
I think it would be unwise to ignore the possibility of a Lipo fire.
Based on my experience over the past 10 years with Lipos, I would not even consider
flying behind one - it is simply not worth it to me to save a few pounds.
Having said that - Lipos are great for driving around in your Tesla - if there's
problem, you can get out and walk - but I don't want to be at 7500 ft when that
happens.
-Jeff
On Friday, November 14, 2014 8:08 AM, Jan de Jong <jan_de_jong@casema.nl> wrote:
On 11/14/2014 4:27 AM, Jeff Luckey wrote:
Suggest updating the weight calculations to include a steel battery box to contain
a lipo fire.
>
>
Is this a little pessimistic?
Some old LiFePO4 on youtube, for those who have not looked there yet
-
vandalism committed upon a Headway 38120 10Ah LiFePO4 cell:
http://www.youtube.com/watch?v=8IBapfB0Imo
http://www.youtube.com/watch?v=52h8IK0IdqI
http://www.youtube.com/watch?v=wkJM8MZkFKU
Are the results valid for A123 ANR26650M1-B cells?
- on the one hand the Headway cell has a lower maximum discharge
rate (10C vs. 30C)
- and is slightly (8% or so) heavier per Ah
- on the other hand the state of charge ranges from fully charged to
very much overcharged
It does not appear as if a fire must be expected in the course of
reasonable or even unreasonable use.
Jan de Jong
Message 3
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I, for one, haven't seen a boring thread here in a loooong time. I'm
learning a lot, and I think the activity indicates the same from others.
Doesn't have a direct application at the moment, but this is how NW ideas
get developed within our community, and I hope no one is intimidated into
killing off the discussion.
I'd suggest the complainer switch to the Digest, and then he can easily
scroll to whatever he is interested in.
Ron
Message 4
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I, for one, haven't seen a boring thread here in a loooong time. I'm
learning a lot, and I think the activity indicates the same from others.
Doesn't have a direct application at the moment, but this is how NW ideas
get developed within our community, and I hope no one is intimidated into
killing off the discussion.
I'd suggest the complainer switch to the Digest, and then he can easily
scroll to whatever he is interested in.
Ron
Message 5
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Subject: | Re: lithium facts |
LiFePO4 or LFP, not Lipo (= LiCoO2 or LCO ). There is a big difference
in safety:
http://batteryuniversity.com/learn/article/types_of_lithium_ion
Jan de Jong
On 11/14/2014 5:41 PM, Jeff Luckey wrote:
> Jan,
>
> I don't think I'm being pessimistic; cautious is a better word.
>
> I have witnessed several lipo fires or their aftermath in R/C
> aircraft. I even remember a Toyota Corolla that burned to the tires
> because of a Lipo that was being charged in the back seat.
>
> In addition, we all know about the Boeing issues. How many dollars did
> they spend on R&D?
>
> I think it would be unwise to ignore the possibility of a Lipo fire.
>
> Based on my experience over the past 10 years with Lipos, I would not
> even consider flying behind one - it is simply not worth it to me to
> save a few pounds.
>
> Having said that - Lipos are great for driving around in your Tesla -
> if there's problem, you can get out and walk - but I don't want to be
> at 7500 ft when that happens.
>
>
> -Jeff
>
>
> On Friday, November 14, 2014 8:08 AM, Jan de Jong
> <jan_de_jong@casema.nl> wrote:
>
>
> On 11/14/2014 4:27 AM, Jeff Luckey wrote:
>> Suggest updating the weight calculations to include a steel battery
>> box to contain a lipo fire.
>>
>
> Is this a little pessimistic?
>
> Some old LiFePO4 on youtube, for those who have not looked there yet -
> vandalism committed upon a Headway 38120 10Ah LiFePO4 cell:
>
> http://www.youtube.com/watch?v=8IBapfB0Imo
> http://www.youtube.com/watch?v=52h8IK0IdqI
> http://www.youtube.com/watch?v=wkJM8MZkFKU
>
> Are the results valid for A123 ANR26650M1-B cells?
>
> - on the one hand the Headway cell has a lower maximum discharge rate
> (10C vs. 30C)
> - and is slightly (8% or so) heavier per Ah
>
> - on the other hand the state of charge ranges from fully charged to
> very much overcharged
>
> It does not appear as if a fire must be expected in the course of
> reasonable or even unreasonable use.
>
> Jan de Jong
> *
>
>
> *
>
>
> *
>
>
> *
Message 6
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Subject: | Re: lithium facts |
Good Afternoon Jeff,
And, if we stopped talking about lithium batteries, where would you post
your reservations?
Personally. I think the more written about them, the better. You will
notice that Boeing is still using the units as are most cell phones and other
small electronic devices.
Happy Skies,
Old Bob
In a message dated 11/14/2014 2:26:19 P.M. Central Standard Time,
jluckey@pacbell.net writes:
Jan,
I don't think I'm being pessimistic; cautious is a better word.
I have witnessed several lipo fires or their aftermath in R/C aircraft. I
even remember a Toyota Corolla that burned to the tires because of a Lipo
that was being charged in the back seat.
In addition, we all know about the Boeing issues. How many dollars did
they spend on R&D?
I think it would be unwise to ignore the possibility of a Lipo fire.
Based on my experience over the past 10 years with Lipos, I would not even
consider flying behind one - it is simply not worth it to me to save a few
pounds.
Having said that - Lipos are great for driving around in your Tesla - if
there's problem, you can get out and walk - but I don't want to be at 7500
ft when that happens.
-Jeff
Message 7
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Subject: | Re: lithium facts |
At 21:27 2014-11-13, you wrote:
>Suggest updating the weight calculations to include a steel battery
>box to contain a lipo fire.
>
>-Jeff
Haven't really prayed over the fire issue much. We
know that the True Blue enclosure was designed, tested
and qualified to contain the worst that a
catastrophic energy release can offer. At same
time, we know that to test the enclosure, the BMS
has to be bypassed and the battery abused with
a 42 volt charger and only after some considerable
time do cells begin to fail. Then they exude a mixture
of flammable gasses . . . which do not 'burn' for lack
of oxygen. The mixture is vented harmlessly over-board
while surface temperatures on the battery enclosure
remain quite modest.
In this case, the energetic mayhem going on within
the battery box isn't really a fire but simply an
array of cells in self-destruction . . . after one or
more cells is abused to failure thus triggering
a cascade.
This kind of testing is the sort of thing the
Navy's Battery labs in Crane, IN used to do.
I suspect they still do. Assume the worst even
if you have to trigger the event yourself . . .
then mitigate the outcome.
Obviously, many segments of the battery market
are embracing lithium products not the least of
which is motorcycles. There are many more
lithium batteries in service outside OBAM
aviation than inside it. The marketplace is
a huge laboratory for testing the general
robustness of available products. I've seen
anecdotal references to 'fires' with
lithium batteries on motorcycles. A couple were
attributed failure of a "mechanical" voltage
regulator to properly charge the battery.
Another spoke a wiring issue (it may have
be the battery wires burning . . . not the
battery).
Given the legacy aviation philosophy for
watching bus voltage and automatically
reacting to overvoltage conditions - combined
design limits that automatically 'soft-charge'
to 50% of chemical capacity, it seems
that the likelihood of an electrically
induced battery event is very low.
I think it unlikely that flame-proof battery
boxes will ever get a warm reception
in light aviation . . . at least not until
the "market laboratory" raises perceptions of
risk to higher levels of apprehension.
The really cool thing is that there are few
imperatives for making the lead->lithium
switch. Our airplanes will continue to fly
as they have for over 100 years. There is
both time and increasing opportunity to build
a well deserved confidence in the new
technology.
Bob . . .
Message 8
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Subject: | Re: lithium facts |
Again, remember that there are several types of Li batteries
each with it's own safety record. If we are talking safety
of Li batteries and are only consideringt LIFePo4 then it is
only appropriate that we refer only to the safety record
of this type of battery.=0A=0A Except for Cessna and Boeing,
both of which, I believe used the cobalt variety, I am una
ware of any type other than LiFePo4 as suggested for our a
ircraft. What the auto makers and computer/cell phone makers a
re using is probably different.=0A=0ARich=0A=0A =0A=0A =0A=0A =0A=0A
-----Original Message-----=0AFrom: Jeff Luckey <jluckey@pacbell.net>=0AT
o: aeroelectric-list <aeroelectric-list@matronics.com>=0ASent: Fri, Nov
14, 2014 2:26 pm=0ASubject: Re: AeroElectric-List: lithium facts=0A
=0A=0A=0AJan,=0A=0A=0AI don't think I'm being pessimistic; cautious
is a better word. =0A=0A=0A=0AI have witnessed several lipo
fires or their aftermath in R/C aircraft. I even remember
a Toyota Corolla that burned to the tires because of a Lip
o that was being charged in the back seat.=0A=0A=0AIn addition
, we all know about the Boeing issues. How many dollars di
d they spend on R&D?=0A=0A=0AI think it would be unwise to
ignore the possibility of a Lipo fire. =0A=0A=0A=0ABased on
my experience over the past 10 years with Lipos, I would n
ot even consider flying behind one - it is simply not wort
h it to me to save a few pounds.=0A=0A=0AHaving said that
- Lipos are great for driving around in your Tesla - if
there's problem, you can get out and walk - but I don't
want to be at 7500 ft when that happens.=0A=0A=0A=0A=0A-Jeff=0A=0A
=0A=0A=0A=0A =0A=0A=0A=0A =0A =0A =0A On Friday, November 14,
2014 8:08 AM, Jan de Jong <jan_de_jong@casema.nl> wrote:=0A
=0A =0A=0A =0A =0A On 11/14/201
4 4:27 AM, Jeff Luckey wrote:=0A =0A =0A
=0ASuggest updating the weight calculations to
include a steel battery box to cont
ain a lipo fire. =0A =0A
=0A =0A =0A =0A Is thi
s a little pessimistic?=0A =0A Some old LiFePO4
on youtube, for those who have not looked there yet
-=0A vandalism committed upon a Headway 38120 10Ah LiFe
PO4 cell:=0A =0A http://www.youtube.com/watch?v=8IBapf
B0Imo=0A http://www.youtube.com/watch?v=52h8IK0IdqI=0A h
ttp://www.youtube.com/watch?v=wkJM8MZkFKU=0A =0A Are t
he results valid for A123 ANR26650M1-B cells? =0A =0A
- on the one hand the Headway cell has a lower
maximum discharge rate (10C vs. 30C)=0A - and
is slightly (8% or so) heavier per Ah=0A =0A
- on the other hand the state of charge ranges from fully
charged to very much overcharged=0A =0A I
t does not appear as if a fire must be expected in the
course of reasonable or even unreasonable use.=0A
=0A Jan de Jong=0A =0A=0A=0A=0A=0A=0A=0A=0A=0A =0A =0A
===========================
===========================
===========================
===========================
===========================
===========================
===========================
=====0A=0A=0A=0A
Message 9
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Subject: | Charging system problem - please help troubleshoot |
Cessna 182J with 60A alternator, mechanical regulator, no overvoltage circuit.
Alternator quit charging - shop found brushes totally worn, slip rings out of
round, and rear bearing noisy. Slip rings trued, brushes replaced, bearing replaced.
Bench and flight tested OK. But on subsequent trip from Calif. to OSH,
following problem occured: about an hour into each leg static would appear
in VHF and ammeter would flicker rapidly between charge and discharge. Turned
off the alternator field with the split master switch, waited a few minutes,
then turned it back on. System resumed charging normally. Replaced the regulator
at OSH with a solid state unit by Zeftronics. On way back to Calif. had
similar problem, only this time the system would simply stop charging, as evidenced
by an alert on the JPI engine analyzer that the system voltage had fallen
into the 12 volt range. As before, I could turn off the field, wait a few minutes
and then restore normal operation (13.9 volts) by turning the field back
on. It would seem something is overheating. Diodes in alternator? Bad field
switch contact? Bad breaker? Bad capacitor?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=433767#433767
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