KR> "Engine-driven alternator?"

[peter]

In practice, the requirements for transponders are interpreted variously by 
different responsible agencies. In my TCA, surrounding SEA, the outer edges of 
the mode C skirt are largely unregulated in practice. If ATC cannot image you 
on radar, they do not want you pinging, nor do they want you talking to them. 
The wording in the FARs allows for an exception if prior permission is granted 
for operation without mode C ...this is assumed to have been granted for the 
entire S. Puget sound, and they don't want you calling them and asking. "Stay 
below radar coverage and keep VFR separation, I've got to deal with all of this 
heavy traffic, and OLY and McCord AFB will ignore you too in VFR conditions."
In the LA TCA I've lost radio while asking for clearance into Ventura.( 
alternator was sparking and RFI overwhelmed the transmitter) In practice, I 
just turned toward White field (uncontrolled) and landed. All of this 
regulation is designed to allow ATC to provide positive separation where 
conflict is  present. If they can't hear or see you, they want you to take care 
of yourself, whether your TC shows a source of electrical power or not. Peter

KR> "Engine-driven alternator?"

[smwood]

The Compufire electronic ignition on my 2180 VW from Great Plains uses 0.6 
to 7.9 amps, idle to wide open throttle, as displayed on my instrument panel 
ammeter.  The more sparks it makes, the more juice it takes.

Sid Wood
Tri-gear KR-2 N6242
Mechanicsville, MD, USA
-- 
>
> The idea of a high-tech battery sounds interesting, but I wouldn't be
> needing it just for the avionics but also for the engine. I plan to have a
> regular VW engine, probably Great Plains, and they normally have one
> magneto, plus a secondary ignition that's powered by the alternator.  So
> either I'd have to fly on one magneto or have a battery system that's able
> to put out enough juice to run a VW secondary ignition system for a whole
> day's flying.  Maybe a lithium battery could do that, but I'm not even 
> sure
> how much juice a VW ignition system uses (or where to find that out).
>
>
> >
> Mike Taglieri
>

KR> "Engine-driven alternator?"

[Mike T]

Thanks for all the replies, though I guess I wasn't completely clear about
the situation.  You can't just go without an alternator just until you get
out of the Mode C airspace.  The FAA rule that lets you have a plane
without ADS -B (or even a transponder, actually) is for planes that NEVER
had an engine-drive alternator from the day they got their airworthiness
certificate up to the present.  The plane has to have lived a totally
alternator-free life.

That's why I was wondering whether "engine-driven" meant the big engine in
the front or any kind of engine.  If an alternator driven by some smaller
engine is allowed, then I could have power as needed without a wind
generator, which is a small generator or alternator out in the airstream
with a little propeller on it (If I faired the generator itself, I could
make one with a removable propeller so I could get rid of the drag when I
didn't need the juice, but I don't see how you could put it on or take it
off without landing).

The idea of a high-tech battery sounds interesting, but I wouldn't be
needing it just for the avionics but also for the engine. I plan to have a
regular VW engine, probably Great Plains, and they normally have one
magneto, plus a secondary ignition that's powered by the alternator.  So
either I'd have to fly on one magneto or have a battery system that's able
to put out enough juice to run a VW secondary ignition system for a whole
day's flying.  Maybe a lithium battery could do that, but I'm not even sure
how much juice a VW ignition system uses (or where to find that out).


Finally, concerning the charging finickiness of Lithium batteries that Tony
mentioned, there's an easy solution to keep charging systems from spiking
the voltage too high -- a zener diode.  Older British motorcycles like my
'72 Norton Commando used this system since before I was born.  A zener
diode connected to ground is an insulator until the voltage rises to a
certain level Then it dumps all voltage above that level to ground.

So old British bikes had primitive alternators with voltage that varied
widely with engine speed, but they also had a zener diode that dumped any
voltage higher than 13.75 V (or something like that) to ground.

There are two problems with using a zener diode this way as the only
voltage regulation.  It's wasteful of power compared to a more
sophisticated system that actually regulates the alternator's output.
 Plus, if it has to dissipate many watts it gets hot, so you need a big
zener diode connected to a good heat sink. The Lucas zener diode found on
an old British motorcycle is as big as a 3/4" nut, is made of copper, and
is bolted to a large aluminum plate out in the airstream.

But those systems had to be overbuilt because they're the only voltage
regulation the system used.  If you had a modern automotive system with
occasional pulses high enough to harm a lithium battery, you could use a
smaller zener diode with its zener breakdown voltage a tiny bit higher than
the one the regular system is supposed to maintain. It would then stop any
pulses higher than the breakdown voltage, but the zener wouldn't have to
work too hard or dissipate much heat.

I assume a system designed for lithium batteries already has something at
least this good, but if you plan to drop a lithium battery into a system
designed for lead-acid batteries, something like this would help.

Mike Taglieri

KR> "Engine-driven alternator?"

[Tony King]

Be very careful with any kind of lithium batteries, including LiFePO4, in
aircraft.  I had a Ballistic EVO2 LiFePO4 battery in my aircraft for about
80 hours with no issues, but I have now removed it after the second of two
significant incidents (one fatal) in Australia caused by LiFePO4 batteries.
 I just didn't want to be worrying about it while in the air - especially
since the battery is directly under the seat in my aircraft.

It's true LiFePO4 is a lot safer than LiPo batteries, but their technical
requirements, discharge characteristics and failure modes are quite
different to lead acid batteries and not well understood by most aircraft
owners.  They do not like being heavily discharged and over-voltage during
charging is a definite no no.  Typical solid state regulators use pulse
width modulation to achieve a well regulated average voltage, but the
voltage of the pulses is whatever the alternator puts out - which can be as
high as 22 volts, well above the 14.6V limit of LiFePO4 batteries.

These batteries are being marketed as direct replacements for lead acid and
it's true that for their weight they make great starter batteries.  But the
marketing doesn't address the differences with lead acid in any way and the
potential for a fire or the discharge of toxic gases (e.g. hydrogen
flouride) exceeds my comfort level in an aircraft, although I'd use one in
a car or motorbike or the like without hesitation.

Another aspect that doesn't seem to be well understood is that while a lead
acid battery shows a gradual drop in voltage as it's discharged, lithium
batteries will hold close to the nominal voltage until quite deep in the
discharge cycle and then the voltage will drop very steeply to below useful
levels.  This has implications in the event of alternator failure if you're
counting on the battery to run the panel or the ignition.  By the time a
drop in voltage is noticed, there's very little time left.

You might notice too that the marketing for lithium batteries tends to
focus on the cold cranking amps of lithium compared with lead acid and on
that basis lithium batteries look great.  But the actual amount of energy
stored in the battery is a lot lower (typically around a third) than a lead
acid battery of equivalent cca performance.  This means the lithium battery
won't be able to run a given load (say a glass panel or a radio stack or an
electronic ignition) for as long as a lead acid battery with equivalent
starting performance.

On the surface these batteries are a great development, but the marketing
that says they're a drop in replacement for lead acid batteries is
misleading.  There are several factors that need to be well understood if
you're planning to put one in an aircraft.

Cheers,

Tony


On 16 July 2014 02:08, brian.kraut--- via KRnet 
wrote:

> Lithium Iron Phosphate batteries are the way to go with aircraft.  They
> have near the capacity to weight and size ratio as Lithim Ion and and
> Lithium Polymer, but they are many times safer.  There is a ton of
> information on them on the web a Google search away.  The biggest
> drawback to most of the Lithium varieties after getting over the safety
> factor is that the cells really need to be balance charged correctly.
> EarthX now has batteries that have all of the complicated charging
> electronics built in the battery.  I got one for my avionics backup for
> the Mustang 2.  I have enough capacity in just 1.3 pounds to fly IFR
> until my fuel tank runs dry if I loose my primary battery and
> alternator.  EFIS automatically switches with its built in two power
> source configuration and I have off/main/backup switches for my nav and
> com radios and my EIS engine monitor.  Probably will add the backup
> position switch to my transponder at some point also.
>
> I highly recommend EarthX and many years from now when my PC680 main
> starting battery goes I will replace it with a 2-3 pound EarthX.
>
> http://earthxmotorsports.com/
>
>
>
>  Original Message 
> Subject: Re: KR> "Engine-driven alternator?"
> From: Jeff Scott via KRnet 
> Date: Tue, July 15, 2014 7:52 am
> To: krnet 
>
> If your plan is to operate a Mode-S with ES transponder, or a UAT Out
> along with Mode C transponder to comply with the 2020 mandate, along
> with a low wattage Comm radio, I would suggest that your lightest option
> would be a light weight solar charger and either a Lithium Ion or
> Lithium Polymer battery pack. The solar charged LiPo combination gives
> you a lot of useful time with the avionics necessary to fly in your area
> without a huge weight penalty.
>
> Caveat: The Lithium Ion and especially the Lithium Polymer batteries can
> be a fire danger if discharged too rapidly (heavy loads like a starter)
> or in a crash scenario if they are punctured. However, when I was
> working in the UAV/Drone world 

KR> "Engine-driven alternator?"

[jose.fuentes at gmail.com]

There is a flexible solar panel that can be adhered to the wing and boom fits 
the contours.






Sent from Windows Mail





From: Dene via KRnet
Sent: ?Tuesday?, ?July? ?15?, ?2014 ?9?:?36? ?AM
To: 'Dan Heath', Dene via KRnet





That's what I had with my solar panel system. My A65 had no alternator so I
had one 9Ahr Yuasa battery online (powering my radio, intercom, gps etc) and
a back-up 3Ahr one off-line being recharged by the solar panel. This panel
was a low profile monocrystalline 12vdc 5.2 watt unit that worked on cloudy
days and even under the sky lights inside the hangar. See
http://tinyurl.com/aooqfv 

A small digital voltmeter monitored the condition of the online battery and
I used a DPDT switch to bring the recharged one online and redirect the
drained one back to the solar panel.


-Original Message-
From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Dan Heath via
KRnet
Sent: 15 July 2014 09:56
To: 'KRnet'
Subject: Re: KR> "Engine-driven alternator?"

May I suggest a back up battery system.  Larry F. and Mark L. and probably
many others have done this.  A battery in good condition will last longer
than you will need to get out of airspace, should you have an electrical
problem.  I never did it, but will definitely build it in to my next
aircraft.




___
Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search.
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KR> "Engine-driven alternator?"

[Mike]

That's what I had with my solar panel system. My A65 had no alternator so I
had one 9Ahr Yuasa battery online (powering my radio, intercom, gps etc) and
a back-up 3Ahr one off-line being recharged by the solar panel. This panel
was a low profile monocrystalline 12vdc 5.2 watt unit that worked on cloudy
days and even under the sky lights inside the hangar. See
http://tinyurl.com/aooqfv 

A small digital voltmeter monitored the condition of the online battery and
I used a DPDT switch to bring the recharged one online and redirect the
drained one back to the solar panel.


-Original Message-
From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Dan Heath via
KRnet
Sent: 15 July 2014 09:56
To: 'KRnet'
Subject: Re: KR> "Engine-driven alternator?"

May I suggest a back up battery system.  Larry F. and Mark L. and probably
many others have done this.  A battery in good condition will last longer
than you will need to get out of airspace, should you have an electrical
problem.  I never did it, but will definitely build it in to my next
aircraft.

KR> "Engine-driven alternator?"

[Virgil N.Salisbury]

 Tony B says that a fully charged battery is good for 17 starts for 
Young
 Eagles rides. Recharge at night for the next day, Virg


 On 7/15/2014 4:55 AM, Dan Heath via KRnet wrote:
> May I suggest a back up battery system.  Larry F. and Mark L. and probably
> many others have done this.  A battery in good condition will last longer
> than you will need to get out of airspace, should you have an electrical
> problem.  I never did it, but will definitely build it in to my next
> aircraft.
>
>   
>
>

KR> "Engine-driven alternator?"

[brian.kraut at eamanufacturing.com]

Lithium Iron Phosphate batteries are the way to go with aircraft.  They
have near the capacity to weight and size ratio as Lithim Ion and and
Lithium Polymer, but they are many times safer.  There is a ton of
information on them on the web a Google search away.  The biggest
drawback to most of the Lithium varieties after getting over the safety
factor is that the cells really need to be balance charged correctly. 
EarthX now has batteries that have all of the complicated charging
electronics built in the battery.  I got one for my avionics backup for
the Mustang 2.  I have enough capacity in just 1.3 pounds to fly IFR
until my fuel tank runs dry if I loose my primary battery and
alternator.  EFIS automatically switches with its built in two power
source configuration and I have off/main/backup switches for my nav and
com radios and my EIS engine monitor.  Probably will add the backup
position switch to my transponder at some point also.  

I highly recommend EarthX and many years from now when my PC680 main
starting battery goes I will replace it with a 2-3 pound EarthX.

http://earthxmotorsports.com/



 Original Message 
Subject: Re: KR> "Engine-driven alternator?"
From: Jeff Scott via KRnet 
List-Post: krnet@list.krnet.org
Date: Tue, July 15, 2014 7:52 am
To: krnet 

If your plan is to operate a Mode-S with ES transponder, or a UAT Out
along with Mode C transponder to comply with the 2020 mandate, along
with a low wattage Comm radio, I would suggest that your lightest option
would be a light weight solar charger and either a Lithium Ion or
Lithium Polymer battery pack. The solar charged LiPo combination gives
you a lot of useful time with the avionics necessary to fly in your area
without a huge weight penalty. 

Caveat: The Lithium Ion and especially the Lithium Polymer batteries can
be a fire danger if discharged too rapidly (heavy loads like a starter)
or in a crash scenario if they are punctured. However, when I was
working in the UAV/Drone world we used Lithium Polymer batteries
exclusively and had some very high G impact crashes. The only damage we
ever saw with the Li-Po batteries was heat damage from discharging them
too rapidly running electric motors on the electric UAVs.

While there are now Li-ion and Li-Po batteries available for aircraft,
at this time I don't recommend them as the primary battery for an
aircraft with a complete alternator/battery system. Thermal damage from
improper or high charge rates is also an issue with these batteries.

-Jeff Scott
Los Alamos, NM

KR> "Engine-driven alternator?"

[Dan Heath]

May I suggest a back up battery system.  Larry F. and Mark L. and probably
many others have done this.  A battery in good condition will last longer
than you will need to get out of airspace, should you have an electrical
problem.  I never did it, but will definitely build it in to my next
aircraft.



See N64KR at   http://KRBuilder.org - Then click on
the pics 



Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il - MVN 

Best KR at 2013 - KR Gathering in Mt. Vernon, Il - MVN 

Best Interior at 2013 - KR Gathering in Mt. Vernon, Il - MVN 

Best Paint at 2013 - KR Gathering in Mt. Vernon, Il - MVN 

Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il - MVN 



Best Interior and Panel at 2008 - KR Gathering in Mt. Vernon, Il - MVN





Daniel R. Heath - Lexington, SC





-Original Message-



Awhile ago, someone asked whether it would be a good idea to have a small
gasoline engine in a plane and use it to keep the battery charged, instead
of having an alternator on the engine. Many people (including me) said this
was impractical and a regular alternator works fine.

KR> "Engine-driven alternator?"

[Mike T]

Awhile ago, someone asked whether it would be a good idea to have a small
gasoline engine in a plane and use it to keep the battery charged, instead
of having an alternator on the engine. Many people (including me) said this
was impractical and a regular alternator works fine.

Now I may be changing my mind. Where I live you can hardly go anywhere
without being within 30 miles of the gigantic Class B created by Kennedy,
Newark, and La Guardia airports (they're so close together the airspaces
merge).  My house is even under it, although I'm an hour's drive from any
of them.

So in 6 years, I'm going to need "ADS-B out" if I want to fly anywhere near
where I live, even though it doesn't do me the slightest bit of good --
ADS-B out is basically so the $ planes that fly IFR all the time can
see me on their screens without  bothering to look out the window. Planes
like that won't care about the cost, but I will, because it'll probably be
more than a VW engine.

The only exception  is if your plane was certified without an
"engine-driven alternator."  That was in the regs for all the old planes
without an electrical system, but many homebuilts are that way too
(including Ken Rand's original KR-1).

A wind-generator is allowed by those regs, but that's a lot of drag. So I'm
wondering: when the regs say you can't have an "engine-driven alternator,"
do they mean driven by THE engine or by ANY engine? If it means THE engine,
then you could have a small engine driving a little alternator (like the
one Great Plains sells for their flywheel-drive engines, and still fly
within the Mode C veil. (I'd probably have solar panels on the fuselage
too, so I wouldn't need it all the time).

Does anybody know anything about this?  I can't be the only tightwad facing
this problem.

Mike Taglieri