Today's Message Index:
----------------------
1. 12:08 AM - Re: Sky-tec not cranking - Canard, Z14, Lyc IO-360 (Werner Schneider)
2. 01:20 AM - Re: Electric Carb heat? (william mills)
3. 06:07 AM - Re: Snap noise when strobes fire (Robert L. Nuckolls, III)
4. 07:24 AM - Re: 10975 Marshall (Robert L. Nuckolls, III)
5. 07:52 AM - Re: (Robert L. Nuckolls, III)
6. 07:56 AM - Re: Bob, wiring of headphone jacks for (Robert L. Nuckolls, III)
7. 08:00 AM - Re: Battery tester (Robert L. Nuckolls, III)
8. 08:02 AM - Re: AEC9005-101LVWarn Auxiliary Battery (Robert L. Nuckolls, III)
9. 08:05 AM - Re: COM antenna feedback (Robert L. Nuckolls, III)
10. 09:12 AM - Re: Sky-tec not cranking - Canard, Z14, Lyc IO-360 (I-Blackler, Wayne R)
11. 10:30 AM - two RG batteries in autos (Joa Harrison)
12. 10:57 AM - Re: RV-List: batteries (czechsix@juno.com)
13. 10:58 AM - adjusting charging on Rotax 912s (Joa Harrison)
14. 11:59 AM - Re: Re: RV-List: batteries (AI Nut)
15. 12:23 PM - Re: adjusting charging on Rotax 912s (Matt Prather)
16. 01:01 PM - velocity completed (plaurence@the-beach.net)
17. 01:06 PM - Re: LED questions (plaurence@the-beach.net)
18. 02:50 PM - Re: two RG batteries in autos (Ned Thomas)
19. 06:18 PM - Re: two RG batteries in autos (Robert L. Nuckolls, III)
20. 06:22 PM - Re: Re: RV-List: batteries (Robert L. Nuckolls, III)
21. 07:32 PM - Re: COM antenna feedback (Dave Morris)
22. 07:45 PM - VLM-14 & LR3C-14 (Chuck Borne)
23. 07:47 PM - Firewall Penetration (brucem@olypen.com)
24. 08:21 PM - Re: Firewall Penetration (Robert L. Nuckolls, III)
25. 08:24 PM - Re: COM antenna feedback (Robert L. Nuckolls, III)
26. 08:34 PM - Little Batteries (Randy)
27. 08:40 PM - Loadmeter (rmickey@ix.netcom.com)
28. 09:26 PM - Re: COM antenna feedback (Dave Morris)
Message 1
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| Subject: | Re: Sky-tec not cranking - Canard, Z14, Lyc IO-360 |
--> AeroElectric-List message posted by: "Werner Schneider" <wernerschneider@compuserve.com>
Hello James,
please make sure, that you have a very clean and tight connection, where the
ground bonding strap hits the engine case.
I had not properly removed the paint below the ground strap on the case and
had exactly this starting problem (and my engine controls got quite hot)!
We did also before the first start preoil the engine with the upper plugs
removed until oil pressure was up, it turned already slow there so I should
have noticed it. We then grounded with a jumper cable from the exhaust to
the battery minus and what a surprise, it immediately started (would not do
this on a pusher without fixing the cable on the airframe), cleaned
toroughly the ear of the engine case, torqued the screw and since then no
hot engine control rods =(;o)
Good luck
Werner
----- Original Message -----
From: "James E. Clark" <james@nextupventures.com>
Subject: RE: AeroElectric-List: Sky-tec not cranking - Canard, Z14, Lyc
IO-360
> --> AeroElectric-List message posted by: "James E. Clark"
<james@nextupventures.com>
>
> I know this was meant for Bob ***AND*** that this is a simplistic
question,
> but ....
>
> Can you turn the engine by hand with and without plugs installed??
>
> Just curious.
>
> James
>
>
> > Problem: I can barely (if at all) turn the prop with the starter.
> > It's a stout engine with 9.2:1 pistons and 100WW mineral oil (for
> > break-in), but I thought I'd at least get 1 blade through during
> > crank!!! The engine is preheated The batteries are warm.
> >
> > Further info: My Ship Ground wires are individual 4AWG from
> >
>
>
Message 2
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| Subject: | Electric Carb heat? |
--> AeroElectric-List message posted by: william mills <courierboy@earthlink.net>
>
>http://www.aircraftspruce.com/catalog/eppages/carbheater.php
>
Guys -
Here's Aircraft Spruce response to my inquiry about the above carb
heat modules:
> CBH001 NO LONGER AVAILABLE
> 07-00676 -- CARBURETOR HEATER DUAL CARB UN -- QTY 1 -- $426.95
Bill
Message 3
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| Subject: | Re: Snap noise when strobes fire |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:14 AM 12/1/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Greg Milner" <tldrgred@execpc.com>
>
>I have wing tip strobes on my RV-4 and my Whelan power supply is in rear
>baggage compartment. Normally have a whooping sound and was instructed to
>try separate battery at the strobe power supply which eliminates the
>whooping sound. Now there is a loud snap in the headset when the strobes
>fire. Any clues?
Have you explored how the noise gets into the system?
Which radio(s) have to be on? Does any volume
control affect intensity of sound?
Bob . . .
Message 4
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| Subject: | Re: 10975 Marshall |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>If the engine is mounted up on the vertical tail and the battery is
>located mid-fuselage, how do you protect the starter and alternator from
>overload as well as the cable running to and from these components? Where
>should the circuit breakers be located?
Alternator feeds into system at the starter
contactor which is on the firewall. ANL current
limiter protects alternator wiring.
Battery and battery contactor are amidships with
major cranking current and ground feeders running
from battery ground and battery contactor to the
engine.
Smaller service ground, on the order of 4AWG
runs from battery ground to instrument panel ground.
Similar feeder runs from battery contactor up
to the main bus forward of panel.
It's sorta like View -C- of figure Z-15 for a seaplane
except the battery is moved back to the midships
ground location.
>Thanks for your help and excellant AeroElectric Manual
Your welcome. I'm pleased that you find it
useful!
I will invite you to join us on the AeroElectric List
to continue this and similar discussions. It's useful to
share the information with as many folks as possible.
A further benefit can be realized with membership on
the list. There are lots of technically capable folks
on the list who can offer suggestions too. You can
join at . . .
http://www.matronics.com/subscribe/
Thanks!
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 5
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--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 02:20 PM 12/1/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Jim Oke <wjoke@shaw.ca>
>
>I am planning to purchase one of those 12 volt "power packs" - aka "auto
>boosters" - as a cost effective source for an RG battery for a homebuilt RV-3.
>
>Are there any pointers in what to look for when buying same? I realize
>that most of the advertising claims about cranking amps and such will tend
>to be a bit flaky but are there any useful guides other than picking up
>the box and guessing the weight of the battery inside?
>
>Saw an AC Delco unit to day mentioning it contained a 17 amp hr battery.
>Suitable for my intended use?
>
>I am writing from Canada so any comment from someone familiar with the
>Canadian Tire line of these devices would be especially helpful.
Virtually ALL such products use a 17 a.h. sealed, lead-acid
battery. Like all popular products, there are many suppliers
with variable skills and integrity. If you're planning to
do a yearly swapout -OR- if your airplane is a day-vfr
only machine and you have flight-bag backups for nav
and comm, then bottom line quality and service life for
your battery choice is not a concern. Give it a try.
Ignore the "ratings" on the box for cranking amps, etc.
They're essentially meaningless or given in a context
that doesn't match any way you'll use the battery.
Bob . . .
Message 6
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| Subject: | Bob, wiring of headphone jacks for |
Flightcom 403D
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Flightcom 403D
At 08:31 AM 12/1/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Nebr RV-8" <nebrrv8@earthlink.net>
>
>
>Jim Muegge
>
>
>Bob,
>
>Quick question,
>
>I am installing a Flightcom 403D in my RV-8 and am wiring the headphone
>jacks. Flightcom shows the jack grounded at the jack. Do I need to run
>shielded cable for the audio out to the jack? If so which end do I
>terminate the shield? Also going to install a small jack for audio in
>for a CD player. Does this jack also need it's ground isolated?
>Thanks for the help. You do a great job.
Thank you for the kind words. Refer to pages at the back
of: http://www.aeroelectric.com/Catalog/AEC/9009/9009-700D.pdf
for guidance. Microphone and headset jacks should never be grounded
locally. Use shielded wire or twisted pair to take all microphone
and/or headset wires back to a ground common with the audio system
preferably at the connector as illustrated in the drawings cited
above.
Bob . . .
Message 7
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| Subject: | Re: Battery tester |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 02:52 PM 11/30/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Terry Watson" <terry@tcwatson.com>
>
>I was at the local Harbor Freight store yesterday and one of the things I
>looked at but did not buy was a battery tester. This thing was on sale for
>about $19, which I think was half price. It had a couple of jumper-cable
>type leads with big alligator grips, a digital readout and a spring loaded
>toggle switch labeled "load" that the instructions said to switch on for no
>more than 10 seconds.
>
>Might this be the kind of batter tester you have suggested, Bob? Here is a
>link to their catalog page:
>http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=90250
>
>I see that it's also available with an analog gauge.
I looked at a similar product at Harbor Freight some time ago.
It's probably useful and the price is low-risk. Testing a battery
under load is the only way to reasonably deduce internal resistance
and to some extent, capacity. However, if you do a yearly swapout
of cheap batteries, this tester will ALWAYS show the battery to
be "good" . . . cause it IS GOOD and you planned it that way.
Bob . . .
Message 8
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| Subject: | Re: AEC9005-101LVWarn Auxiliary Battery |
Manager Wiring.
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Manager Wiring.
At 04:23 PM 11/30/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Tom Parks" <flightwork2@msn.com>
>
>Bob!
>
>I've finished installing your LVWABM in my all electric RV-7 per your
>installation dwg 9005-701B dated 9 February 2003. Turning the DC Master to
>the Bat position shows I have slightly over 12 volts on the voltmeter but
>the Lo Volts warning light does not flash. Turning the Aux Bat switch to the
>Auto position changes nothing. Turning the Aux Bat switch to the ON position
>lights up the Aux Battery On light. I'm not in a position to run the engine
>to charge the as yet, as the project is not ready to go to the airport yet.
>I'm just finishing up the wiring of the airframe while it's in the garage.
>Engine is hung, etc. I have two 18 hr SLA batteries mounted on the firewall
>with B&C 60 amp alternator and the generic Ford voltage regulator. Any
>suggestions as to what is wrong here.
I'd check the wiring to the connector. Make sure all the wires
are in the right holes. These things are pretty simple and
to date, they've always worked when wired right.
Bob . . .
Message 9
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| Subject: | Re: COM antenna feedback |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 12:57 PM 11/30/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
>
>For anyone with a non-metal skin aircraft having trouble with the ground
>plane and/or wanting to try a different type of antenna that has a small
>amount of gain over the typical whip antenna, I've designed a loop antenna
>for composite aircraft that would also work on an aircraft with wood
>skin. The information is at
>http://www.davemorris.com/dave/MorrisDFLoop.html and the antenna can be
>squared off if your tail cone is more square than round.
This is one element of the famous "cubical quad" beam antenna
popularized by hams beginning 40 years or more ago. This is a
highly directional antenna with maximum performance for stations
broadside to the "loop" and sharp nulls off the edges. Consider
a simple, center fed dipole bonded to inside surface of fuselage
with center on side. Wrap ends up and over, down and under the
fuselage curvature. Trim to optimum length with antenna analyzer.
This will provide near-omni directional performance ad a minimum
of fabrication effort and cost.
Bob . . .
Message 10
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| Subject: | Sky-tec not cranking - Canard, Z14, Lyc IO-360 |
--> AeroElectric-List message posted by: "I-Blackler, Wayne R" <wayne.r.blackler@boeing.com>
Yes, I can. I ran the engine two weeks ago.
- Wayne
-----Original Message-----
From: James E. Clark [mailto:james@nextupventures.com]
Subject: RE: AeroElectric-List: Sky-tec not cranking - Canard, Z14, Lyc
IO-360
--> AeroElectric-List message posted by: "James E. Clark" <james@nextupventures.com>
I know this was meant for Bob ***AND*** that this is a simplistic question,
but ....
Can you turn the engine by hand with and without plugs installed??
Just curious.
James
> Problem: I can barely (if at all) turn the prop with the starter.
> It's a stout engine with 9.2:1 pistons and 100WW mineral oil (for
> break-in), but I thought I'd at least get 1 blade through during
> crank!!! The engine is preheated The batteries are warm.
>
> Further info: My Ship Ground wires are individual 4AWG from
>
Message 11
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| Subject: | two RG batteries in autos |
--> AeroElectric-List message posted by: Joa Harrison <flyasuperseven@yahoo.com>
Would two of the 17ah batteries wired in parallel be enough to start and run a
car adequately. You could swap out an aircraft battery every year for a car battery
and then you would have essentially new car batteries every two years.
Joa
---------------------------------
Free Pop-Up Blocker - Get it now
Message 12
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| Subject: | Re: RV-List: batteries |
--> AeroElectric-List message posted by: czechsix@juno.com
Bill,
This is interesting stuff (I'm cc'ing this post to the Aeroelectric list since
it's very relevant to the subject matter discussed there). I've pondered my options
for a backup battery on my dual Lightspeed -8A. I've settled on the 16
ah Odyssey for my main battery, and this should give me a pretty good reserve
if the alternator craps out because my essential loads for panel and one Lightspeed
ignition are 3-4 Amps max. The backup battery will feed only the other
ignition system and is normally charged from the main battery/alternator via a
Schottky diode. So....odds of the backup battery ever being called upon to do
its job of keeping the engine running after everything else is dead is pretty
unlikely. Chances are it will just be dead weight for the life of the airplane.
With that in mind, I'd like to minimize the amount of dead weight that I
have to carry around for that improbable "just in case" scenario.
The cheapest/simplest way (and recommended by Klaus Savier when using dual Lightspeeds)
is to put in a SLA 4.5 ah backup battery. These can be had for $10-30
from what I've seen online, but they weigh 4-5 lbs, and should probably be changed
every other year to make sure the capacity is there if you ever need it.
Lithium Ion sounds appealing due to it's light weight, but as you pointed out,
charging is not so simple (Eric Jones, are you out there? Weren't you working
on a charging management module for Lithium Ions in airplanes?). Not sure
about NiMH...they seem to be getting more popular in lots of consumer stuff.
Too expensive? Charging issues??
But anyway...you are recommending NiCads. My experience with them has been limited
to R/C models and hasn't been too stellar. I always tried to cycle them
properly but even then they seemed to go bad just as fast as the lead acids I've
used (2-4 years). But let's say, ignoring price for a moment, I wanted a 4-5
ah, 12 V NiCad pack. Can you recommend any specific sources to get such an
animal? Google didn't turn up too much for me, and what little I found (in the
$150-200 range) had no specs for weight. And if I were to install a 12V NiCad
pack, can I just drop it in place of the current location for my backup battery,
always having it on charge from the alternator via a Schottky, and expect
it to perform well if needed? How many years would I be able to expect reliable
operation from it before needing replacement?
If I have to replace it every other year (like I would the SLA), and it costs 5-10X
the price and only saves a couple pounds, it obviously doesn't make much
sense. If it only needs to be replaced every decade, then the weight savings
plus reduced hassle of frequent replacements makes the price look more attractive....
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D finishing....
Time: 05:33:03 PM PST US
From: Bill Dube <bdube@al.noaa.gov>
Subject: Re: RV-List: batteries
--> RV-List message posted by: Bill Dube <bdube@al.noaa.gov>
At 05:34 PM 12/2/2003 -0500, you wrote:
>--> RV-List message posted by: "Tracy Crook" <lors01@msn.com>
>
>
>I'll have to go look at the model number but it is a common (large >size) motorcycle
battery from NAPA. They supply several models of >the same physical size
that vary from 17 to 22 AH and I picked the >highest one. Price was highest
too, about $65 as I recall. Trouble >is I don't know what the discharge rate
was for that spec. >Generally, the faster you drain a lead acid battery the
lower its >rating goes, so the difference in ratings might not even be real
if >they used different discharge rates.
There is a formula you can use called "Peukert's Equation" that allows
you to calculate the amp-hr capacity of the battery at any discharge rate. To
set the two constants in the equation, you must know the actual capacity at two
different discharge rates.
Here is a link to a Peukert calculator:
http://www.geocities.com/CapeCanaveral/Lab/8679/battery.html
>It takes about 12 amps to keep my controllers, pumps, ignition coils >(4) and
injectors fed. The 22 AH should last well over 1 hr but it >doesn't.
The amp-hr specification is at the 20 hr discharge rate. Thus, if you
had a draw of 1.1 amps, the battery would supply 22 amp-hrs over the 20 hours
that it took to run it flat. If instead, you pulled 22 amps from it, it would
might last only 15 or 20 minutes before it was dead.
"Stiff" batteries with high CCAs and low internal resistance do not suffer
as badly from this problem. Also, NiCad batteries and Li-Ion batteries lose
very little capacity at modestly high discharges. That is another reason that
they make excellent back-up type batteries.
> The 22 AH rating is probably at a very low current draw. The CCA >rating is
pretty low on this battery but the Mazda rotary doesn't >take much torque to
crank. No valve train to operate and only 3 >moving parts.
If you were to get a battery with a greater CCA, but a slightly lower
amp-hr capacity, it would probably run your airplane longer without an alternator.
>My thanks to Bill Dube for the quick course on batteries. Just the >info I needed
to make an intelligent choice for the -8 I'm building. >I'll probably spring
for the ni-cads and leave the motorcycle battery >in the -4 test mule.
Some of the aircraft style starting batteries can produce
startlingly high CCA's, last nearly forever, and have excellent "dead
alternator" capacity for their weight. They cost a fortune, however.
Typically five to eight times the cost of a similar CCA lead-acid battery.
Ouch!
If you are interested in just the one hour capacity, and are not going
to use the NiCad to start the airplane, the cost is not as painful. For the same
one-hour capacity, a flooded NiCad will weigh about 1/2 as much as a lead-acid
battery and will cost _just_ three to four times as much.
Aircraft starting NiCads are often available used and are often in very
good condition used. However, there are many models and styles and they all
don't have good CCA ratings. You can ruin NiCads if you stray beyond their peak
amperage (discharge) ratings. Also, some folks try to sell worn-out NiCads,
or even give them away, because they are expensive to "throw" away as they contain
cadmium. Load test before you buy a used NiCad!
If you are planning a two battery system for reliability, probably the
best choice would be an AGM for starting and a NiCad for back-up.
Message 13
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| Subject: | adjusting charging on Rotax 912s |
--> AeroElectric-List message posted by: Joa Harrison <flyasuperseven@yahoo.com>
I ran across this post on the S-7 yahoogroup... what do you all think, does this
sound like a reasonable solution or does the problem not exist?
Joa
_____________________
" About Dale's comment regarding charging voltage/batteries: Using a float charger
as you described, would probably do a good job of keeping the battery up.
I use them at home for my motorcycles, too. However there's no AC in the hangar,
except for running my Honda generator. Some background on this: You may
recall my asking if anybody was having kickback problems on cold starting.
This seemed to be related to the battery gradually being discharged. I talked
to the techs at Lockwood and they said that charging voltage in the range of
13.5 to 13.8 was about typical for the 912. Checking the Powersonic Website,
I find that they recommend 13.5 to 13.8 for float charging, that is, charging
over a long period. But for intermittent charge/discharge use, which would be
as used in our aircraft, they recommend the charging voltage of between 14.4
to 14.7.
Adjusting the charging: The white wire from the regulator (the C lead), is the
wire that the regulator uses to look at the voltage. I inserted into this wire,
a 0 - 25 ohm variable resister. I mounted it under the dash on a small tab.
Turning the adjustment will vary the charging voltage anywhere between 13.7
and 15.1 volts. I can adjust it in flight, if I wish. Right now I have it
set at 14.5. I'll let you all know how this is working out in the future.
Joe Shelton S7 242K
Kingman, AZ"
---------------------------------
Free Pop-Up Blocker - Get it now
Message 14
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| Subject: | Re: RV-List: batteries |
--> AeroElectric-List message posted by: "AI Nut" <ainut@earthlink.net>
This is my limited understanding and experience:
Nothing beats the 'ole lead-acid battery for surge demand, such as starting
the engine 8-).
NiMH batteries aren't good for surges, but last quite a long time during
heavy use. However, they won't hold a charge while not being used. Their
self discharge rate is quite high. This is from experience.
Lithium would be ideal for weight and longevity. Not ideal for cost, and
don't know about surge capability.
NiCads are best used by cycles of fully charging and fully discharging, due
to their "memory" characteristics. In engine use, they will die very
quickly.
Fuel cells, maybe???
AI Nut
----- Original Message -----
From: <czechsix@juno.com>
Subject: AeroElectric-List: Re: RV-List: batteries
> --> AeroElectric-List message posted by: czechsix@juno.com
>
>
> Bill,
>
> This is interesting stuff (I'm cc'ing this post to the Aeroelectric list
since it's very relevant to the subject matter discussed there). I've
pondered my options for a backup battery on my dual Lightspeed -8A. I've
settled on the 16 ah Odyssey for my main battery, and this should give me a
pretty good reserve if the alternator craps out because my essential loads
for panel and one Lightspeed ignition are 3-4 Amps max. The backup battery
will feed only the other ignition system and is normally charged from the
main battery/alternator via a Schottky diode. So....odds of the backup
battery ever being called upon to do its job of keeping the engine running
after everything else is dead is pretty unlikely. Chances are it will just
be dead weight for the life of the airplane. With that in mind, I'd like to
minimize the amount of dead weight that I have to carry around for that
improbable "just in case" scenario.
>
> The cheapest/simplest way (and recommended by Klaus Savier when using dual
Lightspeeds) is to put in a SLA 4.5 ah backup battery. These can be had for
$10-30 from what I've seen online, but they weigh 4-5 lbs, and should
probably be changed every other year to make sure the capacity is there if
you ever need it. Lithium Ion sounds appealing due to it's light weight,
but as you pointed out, charging is not so simple (Eric Jones, are you out
there? Weren't you working on a charging management module for Lithium Ions
in airplanes?). Not sure about NiMH...they seem to be getting more popular
in lots of consumer stuff. Too expensive? Charging issues??
>
> But anyway...you are recommending NiCads. My experience with them has
been limited to R/C models and hasn't been too stellar. I always tried to
cycle them properly but even then they seemed to go bad just as fast as the
lead acids I've used (2-4 years). But let's say, ignoring price for a
moment, I wanted a 4-5 ah, 12 V NiCad pack. Can you recommend any specific
sources to get such an animal? Google didn't turn up too much for me, and
what little I found (in the $150-200 range) had no specs for weight. And if
I were to install a 12V NiCad pack, can I just drop it in place of the
current location for my backup battery, always having it on charge from the
alternator via a Schottky, and expect it to perform well if needed? How
many years would I be able to expect reliable operation from it before
needing replacement?
>
> If I have to replace it every other year (like I would the SLA), and it
costs 5-10X the price and only saves a couple pounds, it obviously doesn't
make much sense. If it only needs to be replaced every decade, then the
weight savings plus reduced hassle of frequent replacements makes the price
look more attractive....
>
> --Mark Navratil
> Cedar Rapids, Iowa
> RV-8A N2D finishing....
>
> Time: 05:33:03 PM PST US
> From: Bill Dube <bdube@al.noaa.gov>
> Subject: Re: RV-List: batteries
>
> --> RV-List message posted by: Bill Dube <bdube@al.noaa.gov>
>
> At 05:34 PM 12/2/2003 -0500, you wrote:
> >--> RV-List message posted by: "Tracy Crook" <lors01@msn.com>
> >
> >
> >I'll have to go look at the model number but it is a common (large
>size) motorcycle battery from NAPA. They supply several models of >the
same physical size that vary from 17 to 22 AH and I picked the >highest one.
Price was highest too, about $65 as I recall. Trouble >is I don't know what
the discharge rate was for that spec. >Generally, the faster you drain a
lead acid battery the lower its >rating goes, so the difference in ratings
might not even be real if >they used different discharge rates.
>
> There is a formula you can use called "Peukert's Equation" that
allows you to calculate the amp-hr capacity of the battery at any discharge
rate. To set the two constants in the equation, you must know the actual
capacity at two different discharge rates.
>
> Here is a link to a Peukert calculator:
>
> http://www.geocities.com/CapeCanaveral/Lab/8679/battery.html
>
>
> >It takes about 12 amps to keep my controllers, pumps, ignition coils
>(4) and injectors fed. The 22 AH should last well over 1 hr but it
>doesn't.
>
> The amp-hr specification is at the 20 hr discharge rate. Thus, if
you had a draw of 1.1 amps, the battery would supply 22 amp-hrs over the 20
hours that it took to run it flat. If instead, you pulled 22 amps from it,
it would might last only 15 or 20 minutes before it was dead.
>
> "Stiff" batteries with high CCAs and low internal resistance do
not suffer as badly from this problem. Also, NiCad batteries and Li-Ion
batteries lose very little capacity at modestly high discharges. That is
another reason that they make excellent back-up type batteries.
>
> > The 22 AH rating is probably at a very low current draw. The CCA
>rating is pretty low on this battery but the Mazda rotary doesn't >take
much torque to crank. No valve train to operate and only 3 >moving parts.
>
> If you were to get a battery with a greater CCA, but a slightly
lower amp-hr capacity, it would probably run your airplane longer without an
alternator.
>
>
> >My thanks to Bill Dube for the quick course on batteries. Just the >info
I needed to make an intelligent choice for the -8 I'm building. >I'll
probably spring for the ni-cads and leave the motorcycle battery >in the -4
test mule.
>
> Some of the aircraft style starting batteries can produce
> startlingly high CCA's, last nearly forever, and have excellent "dead
> alternator" capacity for their weight. They cost a fortune, however.
> Typically five to eight times the cost of a similar CCA lead-acid battery.
> Ouch!
>
> If you are interested in just the one hour capacity, and are not
going to use the NiCad to start the airplane, the cost is not as painful.
For the same one-hour capacity, a flooded NiCad will weigh about 1/2 as much
as a lead-acid battery and will cost _just_ three to four times as much.
>
> Aircraft starting NiCads are often available used and are often
in very good condition used. However, there are many models and styles and
they all don't have good CCA ratings. You can ruin NiCads if you stray
beyond their peak amperage (discharge) ratings. Also, some folks try to sell
worn-out NiCads, or even give them away, because they are expensive to
"throw" away as they contain cadmium. Load test before you buy a used NiCad!
>
> If you are planning a two battery system for reliability,
probably the best choice would be an AGM for starting and a NiCad for
back-up.
>
>
Message 15
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| Subject: | Re: adjusting charging on Rotax 912s |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
I have a couple of comments...
Most alternators don't produce their rated voltage until they
turn up to a particular RPM. I'd be a little surprised if the
Rotax alternator only goes up to 13.8V when turned at full RPM
(when loaded below rated output). For reference, the B&C dynamo
on my O200 doesn't make 14V until it turns up to about 1800 RPM
when lightly loaded. I'd also be a little surprised to find that
the Powersonic batteries require higher charging voltage than
other "12V" lead acid batteries.
If the designed regulator voltage setpoint is as low as has been
described, this seems like a quick and dirty solution. However,
it will only useable for regulators on which the sense wire
sinks a fixed amount of current over all operating modes. If the
sense wire current varies with operating condition, the added
resistance may provide unpredictable behavior on some regulator
designs. I believe that these circuits were likely designed with
a low resistance connection to the battery.
Another thought is that it might be possible to have a regulator
tuned to a little higher output voltage. Someone may already be
doing this. I assume there isn't an adjustment screw on the exterior
of the regulator. Maybe there is on the inside. The adjustment
may be made via proper precision component selection at the factory,
though. That would be bit of a bummer.
Finally, its good to keep in mind is that increasing parts count is
almost never good for reliability. As well, I don't think I want
any more 'controls' in my airplane. I'd much rather select components
that take care of themselves while I'm out buzzing around.
Regards,
Matt-
N34RD
> --> AeroElectric-List message posted by: Joa Harrison
> <flyasuperseven@yahoo.com>
>
> I ran across this post on the S-7 yahoogroup... what do you all think,
> does this sound like a reasonable solution or does the problem not
> exist?
>
> Joa
> _____________________
> " About Dale's comment regarding charging voltage/batteries: Using a
> float charger as you described, would probably do a good job of keeping
> the battery up. I use them at home for my motorcycles, too. However
> there's no AC in the hangar, except for running my Honda generator.
> Some background on this: You may recall my asking if anybody was having
> kickback problems on cold starting. This seemed to be related to the
> battery gradually being discharged. I talked to the techs at Lockwood
> and they said that charging voltage in the range of 13.5 to 13.8 was
> about typical for the 912. Checking the Powersonic Website, I find that
> they recommend 13.5 to 13.8 for float charging, that is, charging over a
> long period. But for intermittent charge/discharge use, which would be
> as used in our aircraft, they recommend the charging voltage of between
> 14.4 to 14.7.
>
>
> Adjusting the charging: The white wire from the regulator (the C lead),
> is the wire that the regulator uses to look at the voltage. I inserted
> into this wire, a 0 - 25 ohm variable resister. I mounted it under the
> dash on a small tab. Turning the adjustment will vary the charging
> voltage anywhere between 13.7 and 15.1 volts. I can adjust it in
> flight, if I wish. Right now I have it set at 14.5. I'll let you all
> know how this is working out in the future. Joe Shelton S7 242K
> Kingman, AZ"
>
>
> ---------------------------------
> Free Pop-Up Blocker - Get it now
>
>
Message 16
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| Subject: | velocity completed |
--> AeroElectric-List message posted by: plaurence@the-beach.net
Bob,
You may recall Dr. Fred Marconi's Velociy XL.
You were kind enough to modify a schematic. The wiring was completed a few days
ago and the aircraft will soon be test flown.
Thank you for all you patience and help.
However, your not getting off that easily.I'm working on a RV9A. You'll be hearing
from me soon.
Thanks again
Peter Laurence
do not archive
Message 17
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| Subject: | Re: LED questions |
--> AeroElectric-List message posted by: plaurence@the-beach.net
On 26 Nov 2003 at 17:47, Robert L. Nuckolls, III wrote:
type in LED on Google. You'll find lots of primers.
peter
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net>
>
> At 10:24 PM 11/26/2003 +0000, you wrote:
> >--> AeroElectric-List message posted by: "Neville Kilford"
> ><nkilford@etravel.org>
> >
> >Can I second this enquiry please? Bob, can you point us at a
> >back-to-basics article about LEDs and dimming them? It would be very
> >useful to know, for example, how to calculate the resistor values for
> >one / some LEDs in series / parallel, etc.
> >
> >Thanks in advance.
>
> Eric has done well in this regard already. There's an old article I
> did on the topic several years ago at:
>
> http://www.aeroelectric.com/articles/leds3.pdf
>
> Bob . . .
>
>
> advertising on the Matronics Forums.
> http://www.matronics.com/chat
> ====
>
>
>
>
>
Message 18
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| Subject: | Re: two RG batteries in autos |
--> AeroElectric-List message posted by: "Ned Thomas" <315@cox.net>
Hi Joa,
I bought my 17 ah battery too soon before my experimental was ready. So when
the Toyota 4runner batt died I installed the 17ah AGM sealed battery. It
has the V6 and never started better. Been running for a year that way.
Plenty of cranking power
Ned
----- Original Message -----
From: "Joa Harrison" <flyasuperseven@yahoo.com>
Subject: AeroElectric-List: two RG batteries in autos
> --> AeroElectric-List message posted by: Joa Harrison
<flyasuperseven@yahoo.com>
>
> Would two of the 17ah batteries wired in parallel be enough to start and
run a car adequately. You could swap out an aircraft battery every year for
a car battery and then you would have essentially new car batteries every
two years.
>
> Joa
>
>
> ---------------------------------
> Free Pop-Up Blocker - Get it now
>
>
Message 19
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| Subject: | Re: two RG batteries in autos |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:29 AM 12/3/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: Joa Harrison
><flyasuperseven@yahoo.com>
>
>Would two of the 17ah batteries wired in parallel be enough to start and
>run a car adequately. You could swap out an aircraft battery every year
>for a car battery and then you would have essentially new car batteries
>every two years.
A 17 a.h. battery would work fine in a car. Plenty
of cranking ability. Not sure about the swap-out
your describing. Are you talking about rotating
an aux battery out of the airplane after 2 years
service into a car?
Bob . . .
Message 20
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| Subject: | Re: RV-List: batteries |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 06:55 PM 12/3/2003 +0000, you wrote:
>--> AeroElectric-List message posted by: czechsix@juno.com
>
>
>Bill,
>
>This is interesting stuff (I'm cc'ing this post to the Aeroelectric list
>since it's very relevant to the subject matter discussed there). I've
>pondered my options for a backup battery on my dual Lightspeed -8A. I've
>settled on the 16 ah Odyssey for my main battery, and this should give me
>a pretty good reserve if the alternator craps out because my essential
>loads for panel and one Lightspeed ignition are 3-4 Amps max. The backup
>battery will feed only the other ignition system and is normally charged
>from the main battery/alternator via a Schottky diode. So....odds of the
>backup battery ever being called upon to do its job of keeping the engine
>running after everything else is dead is pretty unlikely. Chances are it
>will just be dead weight for the life of the airplane. With that in mind,
>I'd like to minimize the amount of dead weight that I have to carry around
>for that improbable "just in case" scenario.
>
>The cheapest/simplest way (and recommended by Klaus Savier when using dual
>Lightspeeds) is to put in a SLA 4.5 ah backup battery. These can be had
>for $10-30 from what I've seen online, but they weigh 4-5 lbs, and should
>probably be changed every other year to make sure the capacity is there if
>you ever need it. Lithium Ion sounds appealing due to it's light weight,
>but as you pointed out, charging is not so simple (Eric Jones, are you out
>there? Weren't you working on a charging management module for Lithium
>Ions in airplanes?). Not sure about NiMH...they seem to be getting more
>popular in lots of consumer stuff. Too expensive? Charging issues??
If you want purely a standby battery that's never loaded, consider
an alkaline pack built from D sized cells. Reasonably priced, easy
to acquire. VERY long shelf life. Don't need a charging circuit.
If you plan to maintain a battery from the bus, then I'd recommend
you stay with lead-acid . . . no special charging concerns.
Are you going to have a vacuum system?
Bob . . .
Message 21
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| Subject: | Re: COM antenna feedback |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
True that cubical quads are highly directional. But that's with a 2nd
element. If the antenna only consists of a single element, it is less
directional. I have tested this by constructing a loop that can be
handheld and then rotating it while listening to a signal. You can't
really hear any difference. And since the airport tower you're talking to
is usually either ahead of you or behind you, I think the little bit of
directionality may be constructive. I will be testing this more
scientifically soon.
Dave Morris
At 10:05 AM 12/3/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>At 12:57 PM 11/30/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
> >
> >For anyone with a non-metal skin aircraft having trouble with the ground
> >plane and/or wanting to try a different type of antenna that has a small
> >amount of gain over the typical whip antenna, I've designed a loop antenna
> >for composite aircraft that would also work on an aircraft with wood
> >skin. The information is at
> >http://www.davemorris.com/dave/MorrisDFLoop.html and the antenna can be
> >squared off if your tail cone is more square than round.
>
> This is one element of the famous "cubical quad" beam antenna
> popularized by hams beginning 40 years or more ago. This is a
> highly directional antenna with maximum performance for stations
> broadside to the "loop" and sharp nulls off the edges. Consider
> a simple, center fed dipole bonded to inside surface of fuselage
> with center on side. Wrap ends up and over, down and under the
> fuselage curvature. Trim to optimum length with antenna analyzer.
> This will provide near-omni directional performance ad a minimum
> of fabrication effort and cost.
>
> Bob . . .
>
>
Message 22
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| Subject: | VLM-14 & LR3C-14 |
--> AeroElectric-List message posted by: "Chuck Borne" <caborne3@charter.net>
Bob,
I'm utilizing these components in my RV-4's Z-1 electrical system and was wondering
if there are any special installation considerations for integrating the
two into the system. It seems that there may be some redundant functions/features
between the two.
Thanks,
Chuck Borne
Message 23
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| Subject: | Firewall Penetration |
--> AeroElectric-List message posted by: brucem@olypen.com
Bob,
I would like to use something like your RAC stainless steel flanged elbow
fitting for firewall penetration of wires in my GlaStar. Searches of the
internet and marine hardware stores has not turned up anything equivalent. A
RV-6 builder friend found a SS shower grab bar at Home Depot; the sawn-off ends
could provide flanged elbows. The problem is massive base and wall thickness
and a 1-1/2" diameter - I only need 3/4".
So do you know of any supply source willing to sell me two of the 1" fittings
that you use?
Thanks, Bruce
McGregor
---------------------------------------------
This message was sent using OlyPen's WebMail.
http://www.olypen.com
Message 24
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| Subject: | Re: Firewall Penetration |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 03:47 AM 12/4/2003 +0000, you wrote:
>--> AeroElectric-List message posted by: brucem@olypen.com
>
>Bob,
>
>I would like to use something like your RAC stainless steel flanged elbow
>fitting for firewall penetration of wires in my GlaStar. Searches of the
>internet and marine hardware stores has not turned up anything equivalent. A
>RV-6 builder friend found a SS shower grab bar at Home Depot; the sawn-off
>ends
>could provide flanged elbows. The problem is massive base and wall thickness
>and a 1-1/2" diameter - I only need 3/4".
>
>So do you know of any supply source willing to sell me two of the 1" fittings
>that you use?
I'm working on a source for a heavy (.050") stainless
weldment in sizes 1/2", 3/4" and 1" in right angle and
straight versions. . . should know more after first of
the year.
Bob . . .
Message 25
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| Subject: | Re: COM antenna feedback |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:32 PM 12/3/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
>
>True that cubical quads are highly directional. But that's with a 2nd
>element. If the antenna only consists of a single element, it is less
>directional. I have tested this by constructing a loop that can be
>handheld and then rotating it while listening to a signal. You can't
>really hear any difference. And since the airport tower you're talking to
>is usually either ahead of you or behind you, I think the little bit of
>directionality may be constructive. I will be testing this more
>scientifically soon.
Great. I'd be pleased to hear the results. Do you have a way
to watch an airborne receiver's AGC voltage? I've used flat turns
about a point and a step attenuator to maintain constant AGC
voltage on a distant station to generate some pretty fair
plots of as-installed antenna patterns.
Bob . . .
Message 26
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| Subject: | Little Batteries |
--> AeroElectric-List message posted by: "Randy" <rnvcrothers@comcast.net>
I have heard of RVers, the kind that stay on the ground, switching to the
sealed Odyssey type batteries. This is partly to save some space and maybe
some weight but primarily because of how fast they accept a charge. Is
there something about the construction of these batteries that would allow
them to take a charge faster than a normal lead acid battery? Or is this
just more rumor and BS?
Randy
Message 27
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--> AeroElectric-List message posted by: rmickey@ix.netcom.com
Bob,
I recieved the loadmeter and intalled it today. The Loadmeter still doesn't work.
Did you test it before you sent it?
Ross Mickey
Message 28
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| Subject: | Re: COM antenna feedback |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
I may chop a few inches out of it and hook it up to my 2m ham rig and watch
the S-meter. Unfortunately TI dismantled the antenna test range they used
to have in the field next to my office. It would have been cool to see my
Dragonfly on the top of a 50 foot tower like they used to do with the F-16s
and the Tomahawk cruise missiles we used to see out there.
Dave Morris
do not archive
At 10:24 PM 12/3/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>At 09:32 PM 12/3/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
> >
> >True that cubical quads are highly directional. But that's with a 2nd
> >element. If the antenna only consists of a single element, it is less
> >directional. I have tested this by constructing a loop that can be
> >handheld and then rotating it while listening to a signal. You can't
> >really hear any difference. And since the airport tower you're talking to
> >is usually either ahead of you or behind you, I think the little bit of
> >directionality may be constructive. I will be testing this more
> >scientifically soon.
>
> Great. I'd be pleased to hear the results. Do you have a way
> to watch an airborne receiver's AGC voltage? I've used flat turns
> about a point and a step attenuator to maintain constant AGC
> voltage on a distant station to generate some pretty fair
> plots of as-installed antenna patterns.
>
> Bob . . .
>
>
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