Today's Message Index:
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1. 06:04 AM - Re: A123 Systems Nano-phosphate technology and aircraft (was: (RV4WGH@aol.com)
2. 11:09 AM - Re: 60A Buss fuse attached to baffling? (Robert L. Nuckolls, III)
3. 11:09 AM - Re: Transponder constantly replies (Robert L. Nuckolls, III)
4. 11:29 AM - Re: A123 Systems Nano-phosphate technology and aircraft (was: KillaCycle on Dish Net Tonight) (Robert L. Nuckolls, III)
5. 12:37 PM - Re: A123 Systems Nano-phosphate technology and aircraft (was: KillaCycle on Dish Net Tonight) (Bill Dube)
6. 02:19 PM - Re: A123 Systems Nano-phosphate technology and aircraft (was: (Peter Harris)
Message 1
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| Subject: | Re: A123 Systems Nano-phosphate technology and aircraft |
(was:
Right!
There was an accident near here that badly damaged a Sonex. He had made 2
or 3 changes as suggested by Sonex. Problem with it sticking. Stuck closed!
Carb has been totally redesigned or replaced as I understand it now. Plane
rebuilt.
Wally Hunt
http://discover.aol.com/memed/aolcom30tour
Message 2
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| Subject: | Re: 60A Buss fuse attached to baffling? |
At 05:57 AM 9/4/2007 -0400, you wrote:
>
>9/4/2007
>
>Hello George, You wrote: "I think you have it backwards, you are trying to
>protect the battery."
>
>I was under the impression that fuses and circuit breakers were primarily
>intended to protect the wiring between some source of electrical supply
>and a recipient device on that circuit.
>
>The idea being that a short somewhere along that wiring could generate
>heat, smoke, and possibly fire. The protective device (usually heat
>activated) would open up in the case of excess electron flow because of
>the short and prevent the generation of a dangerous amount of heat and the
>resultant smoke and potential fire.
>
>It has been written earlier that the huge amount of unwanted amps that
>could flow in the alternator B lead in case of a short would be coming
>from the battery and not the alternator. So in that sense maybe one is
>trying to protect the battery from depleting itself as well as protecting
>the B lead wiring in order to avoid smoke and fire.
>
>Perhaps it is a semantic thing -- Bob Nuckolls would you care to comment?
>Thanks.
The thing being protected is mostly the alternator itself. The fault
that opens the b-lead fuse is (1) shorted b-lead (rare) or (2) shorted
diodes in alternator (also rare but more probable than shorted wire).
The energy that will cause damage is going to come from the battery
in terms of many hundreds of amps . . . hence, there's a notion that the
b-lead fuse should be located as close as possible to the battery. I
suggest right next to the starter contactor and b-lead shunt (if used).
If not fused and the diodes short, it will take out stator wires
causing much smoke and a much higher repair bill. Also, if the battery
is soggy [of course, nobody who reads this list goes flying with a
soggy battery], then a hard short could take the battery down too
and make the whole panel go dark. Under the best scenario, a well
maintained battery supplies 1000+ amps for milliseconds necessary
to open the fuse and repairs are a relatively simple maintenance
event.
Bob . . .
Message 3
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| Subject: | Re: Transponder constantly replies |
At 07:23 AM 9/4/2007 -0500, you wrote:
><pete.howell@gecko-group.com>
>
>
>Hello,
>
>I have an older transponder that seems to constantly generate replies
>while airborne(solid light almost all the time). ATC reports it is
>working great, but I think it is causing issues with a traffic scope
>I have installled. Others report their transponder reacts the same
>way, but more tell me they only get a reply on a sweep. I am
>wondering if a bad antenna cable or connector could cause this?
>Other thoughts welcome.
I used to test transponders for reply codes by laying
a noisy drill motor under the aircraft with a rubber
band holding the trigger-switch ON. This would cause
the transponder to dump a continuous stream of replies
when there was no radar interrogation present.
It MIGHT be that your transponder is seeing some
kind of noise source that produces a similar response.
Bob . . .
----------------------------------------
( "Physics is like sex: sure, it may )
( give some practical results, but )
( that's not why we do it." )
( )
( Richard P. Feynman )
----------------------------------------
Message 4
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| Subject: | Re: A123 Systems Nano-phosphate technology and aircraft |
(was: KillaCycle on Dish Net Tonight)
At 04:32 PM 9/5/2007 -0600, you wrote:
>You can do a fantastic electric motor glider, but nothing long range.
>Imagine if gasoline weighed about 100 lbs per gallon and you will
>understand the range issue.
>
>These "Nano-Phosphate" type cells will make a big dent in the weight of
>airplanes soon. As you can see, they put out a huge amount of power for
>their weight, so they will be perfect starting batteries for airplanes.
>This specific type of battery has none of the safety issues that other
>high-power batteries have.
One of my principles is working with the A123
products with an eye toward a certified replacement
of SVLA/NiCAD batteries on T/C aircraft. So far,
they've reporting nothing that suggests that the
the task is impractical but successful integration
of Li-Ion technology into aircraft WILL require
a battery-friendly charging system (read new smart
regulator for existing aircraft) or a drop-in form-fit-
function device that includes battery management
capabilities. The Li-Ion's are not drop-in replacments
for SVLA . . . they won't take the "abuse".
Bob . . .
Message 5
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| Subject: | Re: A123 Systems Nano-phosphate technology and aircraft |
(was: KillaCycle on Dish Net Tonight)
Whomever is designing the electronics doesn't have real experience with
A123 Systems cells. They think they are dealing with conventional Li-Ion
cells, and they are wrong.
A123 Systems nano-phosphate cells are quite different than other
Li-Ion cells. They will take a LOT of abuse. About the same amount as an
AGM. It is straightforward to make a drop-in replacement for a 12 volt
(or 24 volt) lead-acid battery using A123 Systems cells. The existing
charging system will work just fine. (It must have the voltage set
somewhere between 13.5 and 14.8 volts.)
In an airplane, you would want a warning that alerted the pilot that
the system was going over 14.8 volts and would make noise if the system
was going over 15 volts. It would also be useful to know if the battery
temperature was going over 80 Celsius. (You can go up to about 100 C
without damage, but no higher or you risk venting the cells and damaging
the plastic separator.)
>>> Case study <<<<
I have had a 3.5 lb A123 Systems battery running in my completely
unmodified GMC van for the past 7 months. It snaps the engine over much
better than the original 35 lb lead-acid battery.
Let's talk about abuse. My wife left my van door unlocked and
someone rifled my glove box and left it open with the light on. This
killed the battery and it sat at ZERO VOLTS for over a week. I thought,
"So much for THAT battery." I then decided to do what the typical
consumer would do and I connected up the 3.5 lb completely dead battery
to a fully-charged car battery with jumper cables. Hundreds of amps
flowed and slightly warmed the cables. I waited a couple of minutes for
the 3.5 lb battery voltage to come up, disconnected the jumper cables
(the worst thing you could do) and cranked up the van. It started
instantly. The alternator then gave the 3.5 lb battery ~100 amps until
it came up to 13.4 volts and then tapered off. The BMS showed that all
the cells were still in balance!
This was five months ago. I haven't capacity-tested the battery, but
I can't tell the difference in cranking performance. It was just as if
nothing had happened. I even left it parked for 5 weeks while I was out
of town and it cranked right up without a problem.
If you were to torture a conventional Li-Ion battery like this, it
would have burst into flames, or at least it would have just burst. I
tell this story to folks with years of experience with conventional
Li-Ion cells and they cringe when I get to the part about the jumper
cables. :-)
The A123 Systems cells will, indeed, "take the abuse". I have a very
simplistic charge-balancing electronics (BMS) on my GMC van battery.
Nothing fancy is needed.
If you overcharge them grossly, they will vent a small amount of
flammable vapor (like paint thinner.) If there is an ignition source,
this vapor could catch fire. The cells can also burst if overcharged
severely. That is the extent of the hazard this technology presents.
Bill Dube'
Robert L. Nuckolls, III wrote:
> <nuckollsr@cox.net>
>
> At 04:32 PM 9/5/2007 -0600, you wrote:
>
>> You can do a fantastic electric motor glider, but nothing long range.
>> Imagine if gasoline weighed about 100 lbs per gallon and you will
>> understand the range issue.
>>
>> These "Nano-Phosphate" type cells will make a big dent in the weight
>> of airplanes soon. As you can see, they put out a huge amount of
>> power for their weight, so they will be perfect starting batteries
>> for airplanes. This specific type of battery has none of the safety
>> issues that other high-power batteries have.
>
>
> One of my principles is working with the A123
> products with an eye toward a certified replacement
> of SVLA/NiCAD batteries on T/C aircraft. So far,
> they've reporting nothing that suggests that the
> the task is impractical but successful integration
> of Li-Ion technology into aircraft WILL require
> a battery-friendly charging system (read new smart
> regulator for existing aircraft) or a drop-in form-fit-
> function device that includes battery management
> capabilities. The Li-Ion's are not drop-in replacments
> for SVLA . . . they won't take the "abuse".
>
> Bob . . .
>
>
Message 6
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| Subject: | A123 Systems Nano-phosphate technology and aircraft |
(was:
Wally I think not redesigned. I attempted to get cooperation from Aerocarb
CEO 6 months ago to redesign. The slide is pushed off centre by the cable
and jams. In return I got personal abuse and was barred from the Jabiru
engines list which he moderates. The principle is blame the installation
there is nothing wrong with the product. When I requested a refund I was
told to sell it on Ebay.
Peter
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
RV4WGH@aol.com
Sent: Friday, 7 September 2007 11:02 PM
Subject: Re: AeroElectric-List: A123 Systems Nano-phosphate technology and
aircraft (was:
Right!
There was an accident near here that badly damaged a Sonex. He had made 2
or 3 changes as suggested by Sonex. Problem with it sticking. Stuck
closed! Carb has been totally redesigned or replaced as I understand it
now. Plane rebuilt.
Wally Hunt
_____
<http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982> .
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