Today's Message Index:
----------------------
1. 06:45 AM - Re: Lithium batteries (Robert L. Nuckolls, III)
2. 09:27 AM - New Over-Voltage Protection Architecture (user9253)
3. 09:41 AM - EarthX lithium (Robert L. Nuckolls, III)
4. 09:49 AM - Re: New Over-Voltage Protection Architecture (Robert L. Nuckolls, III)
5. 09:57 AM - EarthX lithium (Robert L. Nuckolls, III)
6. 10:22 AM - Re: New Over-Voltage Protection Architecture (user9253)
7. 10:46 AM - Re: EarthX lithium (Robert Borger)
8. 11:18 AM - Re: EarthX lithium (Robert L. Nuckolls, III)
9. 11:21 AM - Re: Re: New Over-Voltage Protection Architecture (Robert L. Nuckolls, III)
10. 12:02 PM - Re: EarthX lithium (Robert Borger)
Message 1
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| Subject: | Lithium batteries |
At 08:53 PM 3/15/2014, you wrote:
><mike@aeromotogroup.com>
>
>Mr. Brent Regan is apparently an expert on the use of Lithium batteries in
>aircraft. I attempted to start a discussion on the LML list a few years ago
>and he shut me down with his expertise. You may want to tap into his
>exhaustive research on the subject:
>http://lancair.net/lists/lml/Message/57030-P.txt
Brent and I have crossed paths in the past but
I'm having trouble recalling now when, where and
in what context. I'll drop him a note and see
if he would be willing to collaborate on the
last installment of the series on batteries.
Thanks for the heads-up!
Bob . . .
Message 2
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| Subject: | New Over-Voltage Protection Architecture |
Suppose that it is not desired that a crowbar type over-voltage protection device
to have the ability to disable the alternator on an aircraft with an electrically
dependent engine or electrically dependent instruments.
In the event that an externally regulated alternator puts out too high voltage,
is it feasible for the O.V. protection device to insert a series resistance
into the alternator field circuit instead of shorting it out? The amount of
resistance could be determined through trial and error to give 12-13 volts with
normal aircraft loads.
Or a resistor could be permanently installed in the alternator field circuit,
but normally shorted out by the O.V. protection device. In case of high voltage
or O.V. protection malfunction, the short across the resistor will be opened.
The alternator will then operate at reduced output determined by the load.
A low voltage warning will be indicated to the pilot who can increase or decrease
aircraft loads to fine tune the system voltage if desired. No circuit
breaker will pop nor will a fuse blow. The pilot or mechanic can troubleshoot
the low voltage condition after landing.
The advantage of this method of over-voltage protection is that the alternator
output will be reduced instead of completely disabled. Question is, is it practical
and feasible?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=420469#420469
Message 3
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I just became aware of EarthX batteries based on
comments here on the list. I visited their website
and studied a variety of assertions and comparisons
designed to promote sales. At first blush, these
folks are hanging their marketing hats on the same
philosophy as other suppliers of lithium technologies.
See attached document . . .
The DEARTH of good engineering data for these
products makes it difficult if not impossible to
craft a well considered integration of the current
COTS (commericial off the shelf) offerings onto
airplanes.
I had to delay submission of the last of four
Kitplanes articles for a month . . . not because
theres a paucity of choices . . . but because the
folks selling them can't define performance in
rational numbers. Still digging . . .
Bob . . .
Message 4
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| Subject: | Re: New Over-Voltage Protection Architecture |
At 11:26 AM 3/17/2014, you wrote:
Suppose that it is not desired that a crowbar type over-voltage
protection device to have the ability to disable the alternator on an
aircraft with an electrically dependent engine or electrically
dependent instruments.
In the event that an externally regulated alternator puts out too
high voltage, is it feasible for the O.V. protection device to insert
a series resistance into the alternator field circuit instead of
shorting it out? The amount of resistance could be determined
through trial and error to give 12-13 volts with normal aircraft loads.
Why not just switch in a stand-by regulator?
http://tinyurl.com/npya5l7
. . .they're really cheap . . .
In the early days of the alternator fitted
C337 and Barons, controlled stand-by regulators
were part of the system . . .
Or a resistor could be permanently installed in the alternator field
circuit, but normally shorted out by the O.V. protection device. In
case of high voltage or O.V. protection malfunction, the short across
the resistor will be opened. The alternator will then operate at
reduced output determined by the load. A low voltage warning will be
indicated to the pilot who can increase or decrease aircraft loads to
fine tune the system voltage if desired. No circuit breaker will pop
nor will a fuse blow. The pilot or mechanic can troubleshoot the low
voltage condition after landing.
The advantage of this method of over-voltage protection is that the
alternator output will be reduced instead of completely
disabled. Question is, is it practical and feasible?
Pretty tough to sell . . . a voltage regulator
is an exceedingly agile device that will willingly
produce any field excitation level from near zero
to full bus voltage depending on loads and rpm.
You could conduct some experiments on your airplane
to deduce the size of such a resistor but . . . but
be sure to explore the "non nominal" conditions
to assess performance.
Bob . . .
Message 5
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Skip,
Had a reader recommend EarthX lithium batteries for airplanes.
Seems they're courting Van's and some other suppliers of
kit aircraft and parts.
Downloaded a page of their marketing pitch. I commented on
it and published it back to my forum.
I'm going to contact EarthX for more information on ENERGY
numbers and a functional description of their 'battery
management system'.
See attached . . .
Bob . . .
Message 6
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| Subject: | Re: New Over-Voltage Protection Architecture |
> Why not just switch in a stand-by regulator?
> http://tinyurl.com/npya5l7
> . . .they're really cheap . . .
>
Great idea. Thanks Bob
My RV-12 has a permanent magnet alternator. So I can not try out the series resistor
idea. I like to think about alternative ways of wiring an airplane. Most
of the time, the old way is the best way. :-)
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=420475#420475
Message 7
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| Subject: | Re: EarthX lithium |
Bob N,
In your commentary on the FAQ. At the end there is a question about deeply discharging
the battery. Your comment is So if I go off and leave the master switch
ON, odds are that by the time I get back to fly again, my battery is trash?
I can answer that in one word - YES. Your battery is trash.
If this battery is like the one I purchased to test, it does not have a BMS which
auto-disconnects to protect cells from over-discharge.
I flew with this battery for several months and did some simple ground testing.
Tested things like - How long would it last running all the electrics (EIS,
EFIS, radio & transponder), how long just running the EIS, radio & transponder,
how long just running the EIS & radio and how long just running the EIS & transponder?
After each test I put the high-tech charger on and recharged with
the cell balance in effect. I didnt get to the last of the questions because
after the EIS, radio & transponder test I managed to put the charger on but left
the Master on as well. When I came back a couple days later to continue the
testing the battery was fully discharged and would not accept recharging. It
was trashed.
FYI, in testing the battery I found that it would run the whole electrical system
about 5 minutes. It would run the EIS, radio & transponder about 7 minutes.
Overall, I was not impressed with the LiFePo battery. It was extremely light and
it started my Rotax 914 quickly and easily. After starting the engine and
flying for a while, it would be properly and fully charged when back on the ground.
Unfortunately, from my limited testing, it didnt have any real legs to
run things on its own and it requires a lot of fancy, high-tech, gear to keep
it happy. And take great care not discharge it fully.
Just my 2 from my very limited experience.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
On Mar 17, 2014, at 11:40 AM, Robert L. Nuckolls, III <nuckolls.bob@aeroelectric.com>
wrote:
I just became aware of EarthX batteries based on
comments here on the list. I visited their website
and studied a variety of assertions and comparisons
designed to promote sales. At first blush, these
folks are hanging their marketing hats on the same
philosophy as other suppliers of lithium technologies.
See attached document . . .
The DEARTH of good engineering data for these
products makes it difficult if not impossible to
craft a well considered integration of the current
COTS (commericial off the shelf) offerings onto
airplanes.
I had to delay submission of the last of four
Kitplanes articles for a month . . . not because
theres a paucity of choices . . . but because the
folks selling them can't define performance in
rational numbers. Still digging . . .
Bob . . . <FAQs about EarthX Lithium Batteries.pdf>
Message 8
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| Subject: | Re: EarthX lithium |
At 12:46 PM 3/17/2014, you wrote:
Bob N,
In your commentary on the FAQ. At the end there
is a question about deeply discharging the
battery. Your comment is =93So if I go off and
leave the master switch ON, odds are that by the
time I get back to fly again, my battery is trash?
I can answer that in one word - YES. Your battery is trash.
If this battery is like the one I purchased to
test, it does not have a =93BMS=94 which
auto-disconnects to protect cells from over-discharge.
Which part number of battery did you test?
I flew with this battery for several months and
did some simple ground testing. Tested things
like - How long would it last running all the
electrics (EIS, EFIS, radio & transponder), how
long just running the EIS, radio & transponder,
how long just running the EIS & radio and how
long just running the EIS & transponder? After
each test I put the high-tech charger on and
recharged with the cell balance in effect. I
didn=92t get to the last of the questions because
after the EIS, radio & transponder test I managed
to put the charger on but left the Master on as
well. When I came back a couple days later to
continue the testing the battery was fully
discharged and would not accept recharging. It was trashed.
Good data point . . .
FYI, in testing the battery I found that it would
run the whole electrical system about 5
minutes. It would run the EIS, radio & transponder about 7 minutes.
Overall, I was not impressed with the LiFePo
battery. It was extremely light and it started
my Rotax 914 quickly and easily. After starting
the engine and flying for a while, it would be
properly and fully charged when back on the
ground. Unfortunately, from my limited testing,
it didn=92t have any real legs to run things on its
own and it requires a lot of fancy, high-tech,
gear to keep it happy. And take great care not discharge it fully.
Just my 2=A2 from my very limited experience.
From your limited observations, what would you estimate
the energy content to be for the model you tested? In
other words, what was the demand for the EIS, radio and
transponder? Apparently it would satisfactorily crank
an engine for some time.
I have emailed EarthX requesting the name and address
for an individual who can supply technical date in detail
sufficient to make good system integration choices.
Thanks for the data points!
Bob . . .
Message 9
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| Subject: | Re: New Over-Voltage Protection Architecture |
>Great idea. Thanks Bob
>My RV-12 has a permanent magnet alternator. So I can not try out
>the series resistor idea. I like to think about alternative ways of
>wiring an airplane. Most of the time, the old way is the best way.
ALL ways are worthy of considered thought.
It's just as valuable to know what DOES work
as those things which are QUESTIONABLE.
I've often asked builders to get on the List
and tell us what was tried that didn't work . . .
like Bob's posting on EarthX . . .
It helps avoid discovering a bad idea over and
over again!
Bob . . .
Message 10
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| Subject: | Re: EarthX lithium |
Bob N,
LiFePo battery - AeroVoltz 8 Cell Lithium Battery.
http://aerovoltz.net/en/
The Sport EFIS consumes about 1 amp according to the documentation. I
don=92t have good numbers on the GRT EIS4000 but I would allow about 1
amp with all the sensors, back light, display, etc. I may be able to
get a better number next trip to the hanger. The radio and transponder
are MicroAir M760Q & T2000 SFL. =46rom the documentation, I=92d say
they each use about 250-300ma with the backlight on and not
transmitting.
The battery turned the 914 over very smartly. The engine is easy to
start in any case so it wasn=92t really working that hard. Three or 4
prop blades and it starts. That=92s 2 or 3 rotations of the engine.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
On Mar 17, 2014, at 1:17 PM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com> wrote:
At 12:46 PM 3/17/2014, you wrote:
<rlborger@mac.com>
Bob N,
In your commentary on the FAQ. At the end there is a question about
deeply discharging the battery. Your comment is =93So if I go off and
leave the master switch ON, odds are that by the time I get back to fly
again, my battery is trash?
I can answer that in one word - YES. Your battery is trash.
If this battery is like the one I purchased to test, it does not have a
=93BMS=94 which auto-disconnects to protect cells from over-discharge.
Which part number of battery did you test?
I flew with this battery for several months and did some simple ground
testing. Tested things like - How long would it last running all the
electrics (EIS, EFIS, radio & transponder), how long just running the
EIS, radio & transponder, how long just running the EIS & radio and how
long just running the EIS & transponder? After each test I put the
high-tech charger on and recharged with the cell balance in effect. I
didn=92t get to the last of the questions because after the EIS, radio &
transponder test I managed to put the charger on but left the Master on
as well. When I came back a couple days later to continue the testing
the battery was fully discharged and would not accept recharging. It
was trashed.
Good data point . . .
FYI, in testing the battery I found that it would run the whole
electrical system about 5 minutes. It would run the EIS, radio &
transponder about 7 minutes.
Overall, I was not impressed with the LiFePo battery. It was extremely
light and it started my Rotax 914 quickly and easily. After starting
the engine and flying for a while, it would be properly and fully
charged when back on the ground. Unfortunately, from my limited
testing, it didn=92t have any real legs to run things on its own and it
requires a lot of fancy, high-tech, gear to keep it happy. And take
great care not discharge it fully.
Just my 2=A2 from my very limited experience.
=46rom your limited observations, what would you estimate
the energy content to be for the model you tested? In
other words, what was the demand for the EIS, radio and
transponder? Apparently it would satisfactorily crank
an engine for some time.
I have emailed EarthX requesting the name and address
for an individual who can supply technical date in detail
sufficient to make good system integration choices.
Thanks for the data points!
Bob . . .
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