I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
recently had a situation where I ran out of juice after 4 attempted
starts. While I am sure that I can improve my starting technique (I am
a newbie for this particular plane), I would like to have a bit more
power in my battery, especially in very cold conditions such as we have
up here in central Wisconsin.

An A&P told me recently that I am "stuck" with my G25 battery. He said
that he tested it and that it was "fine."

Based on a recent article in "Aviation Consumer", I learned that the G25
has only about 225 cold cranking amps. I noted that the G35S has 250
cold cranking amps.

(1) Is it true that I am stuck with a G25 battery and that NO OTHER
battery in the world can go in my plane? I find that a little hard to
believe.

(2) If there are other possibilities, can someone recommend one that has
better cold cranking amps that the G25?

Thanks in advance.

-Sami (N2057M, Piper Turbo Arrow III owner)

On 26-Jan-2004, "O. Sami Saydjari" > wrote:

> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
> recently had a situation where I ran out of juice after 4 attempted
> starts.

Since you live in central Wisconsin, you know how cold can sap a battery's
charge, particularly if left idle for a few days. But when you say it "ran
out of juice after 4 attempted starts" I am wondering (a) what you mean by
no juice, and (b) what constitutes an "attempt." If you mean that the
battery is discharged to a point where the prop will no longer turn with the
starter, that could mean a lot of things, including a defective starter. If
you mean the battery is completely flat (for example, will not power the
radios), then It could be a problem with your charging system or the leads
to the battery.

Four prolonged start attempts with a very cold engine could easily drain a
very cold battery. How, if at all, do you preheat?


> While I am sure that I can improve my starting technique (I am
> a newbie for this particular plane), I would like to have a bit more
> power in my battery, especially in very cold conditions such as we have
> up here in central Wisconsin.

I have an Arrow IV, also with an IO-360. I have found that when the engine
is cold (and "cold" here in the Seattle area is pretty mild by your
standards) it likes a very healthy shot of priming. I leave the mixture
rich and the electric pump on until fuel pressure begins to register (it
takes maybe 7-8 seconds), then pull the mixture back and crank. Then it
usually starts without difficulty. I presume that you have studied the
start procedure shown in the manual. The most critical (and perhaps
counter-intuitive) thing to remember is that the mixture needs to be in full
LEAN (i.e. cutoff) position while cranking. You need to keep your right
hand on the mixture while you turn the key with your left hand so that you
can quickly move the mixture to full rich as soon as the engine begins to
fire.


> (1) Is it true that I am stuck with a G25 battery and that NO OTHER
> battery in the world can go in my plane? I find that a little hard to
> believe.

The battery box in a normally aspirated Arrow is pretty tight -- not much
room for a larger battery. Weight and CG are also considerations.

--
-Elliott Drucker

"O. Sami Saydjari" > wrote in message ...
> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
> recently had a situation where I ran out of juice after 4 attempted
> starts.

The other thing you may wish to look at is the cable between the
battery and the engine. I believe that a lot of the Cherokee's benefit
from having this replaced.

Of course, your other option is to get an APU cable for your plane.
Used to help the Saratoga in the next tie down start his plane on
cold mornings.

Sami,
You can install a Concorde www.concordebattery.com CB-25, CB-25XC, RG-25
or RG-25XC.
1) Four attempted starts depends on how long you were trying. Most
starters have a 30 second continuous limit.
using that that is 2 full minutes of cranking. That would just about be
the limit for battery capacity.
2) Has your aircraft had the original battery cable (Aluminum in most
models) with the Bogert Copper Cable kit? This improves starting speed
and longevity.
3) Find a more open minded A&P Concorde recently modified the battery
cases so they will fit in the Piper Battery Box.
4) Place your battery on a Charger for an hour a day. Low current. A
standard appliance timer works fine.
5) Use a battery heater.

Michelle (A&P)


O. Sami Saydjari wrote:

> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
> recently had a situation where I ran out of juice after 4 attempted
> starts. While I am sure that I can improve my starting technique (I
> am a newbie for this particular plane), I would like to have a bit
> more power in my battery, especially in very cold conditions such as
> we have up here in central Wisconsin.
>
> An A&P told me recently that I am "stuck" with my G25 battery. He
> said that he tested it and that it was "fine."
>
> Based on a recent article in "Aviation Consumer", I learned that the
> G25 has only about 225 cold cranking amps. I noted that the G35S has
> 250 cold cranking amps.
>
> (1) Is it true that I am stuck with a G25 battery and that NO OTHER
> battery in the world can go in my plane? I find that a little hard to
> believe.
>
> (2) If there are other possibilities, can someone recommend one that
> has better cold cranking amps that the G25?
>
> Thanks in advance.
>
> -Sami (N2057M, Piper Turbo Arrow III owner)
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

As others have noted, there a number of batteries STCed for your airplane.
I am not sure how your mechanic tested your battery but just testing the
specific gravity or voltage is not really an adequate test of starting
ability. There was a recent article in Aviation Consumer about the
differences between batteries. I hope that you are preheating the engine
before starting in the cold and if you have Tanis heaters, you can add a
battery heater which will help a lot.

Mike
MU-2


"O. Sami Saydjari" > wrote in message
...
> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
> recently had a situation where I ran out of juice after 4 attempted
> starts. While I am sure that I can improve my starting technique (I am
> a newbie for this particular plane), I would like to have a bit more
> power in my battery, especially in very cold conditions such as we have
> up here in central Wisconsin.
>
> An A&P told me recently that I am "stuck" with my G25 battery. He said
> that he tested it and that it was "fine."
>
> Based on a recent article in "Aviation Consumer", I learned that the G25
> has only about 225 cold cranking amps. I noted that the G35S has 250
> cold cranking amps.
>
> (1) Is it true that I am stuck with a G25 battery and that NO OTHER
> battery in the world can go in my plane? I find that a little hard to
> believe.
>
> (2) If there are other possibilities, can someone recommend one that has
> better cold cranking amps that the G25?
>
> Thanks in advance.
>
> -Sami (N2057M, Piper Turbo Arrow III owner)
>

Michelle P wrote:
>
> You can install a Concorde www.concordebattery.com CB-25, CB-25XC, RG-25
> or RG-25XC.

Are any of these going to give him more cranking power than the Gill?

George Patterson
Great discoveries are not announced with "Eureka!". What's usually said is
"Hummmmm... That's interesting...."

"Testing" the battery means making sure it is fully charged, then
discharging it using a known load current, timing how long it takes
the voltage to reach 11.5V, and then computing the capacity by
multiplying the time to reach 11.5V by the load current.

According to Gill & the FAA, your battery should be up to delivering
a load current representing all the stuff it takes to get safely on the
ground for 30 min: this should include engine instruments, fuel gauges,
electric gyros, radios, transponder and some lighting.

A guess for the essential electrical load on your aircraft would
be about 25A. To test the battery, connect a 12V/25A=0.48 Ohm,
12V*25A=300W resistor to the battery, and time how long it takes
the battery to reach 11.5V. If your battery wont hold up this
load for 30 min, then it should be replaced...

Cranking is a separate test. An automotive service-station type of
carbon-pile battery tester can be used to put a load of ~225A on
the battery for 3 or so minutes. If the battery peters out short of
3 min, then replace it.

MikeM

O. Sami Saydjari wrote:
> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
> recently had a situation where I ran out of juice after 4 attempted
> starts. While I am sure that I can improve my starting technique (I am
> a newbie for this particular plane), I would like to have a bit more
> power in my battery, especially in very cold conditions such as we have
> up here in central Wisconsin.
>
> An A&P told me recently that I am "stuck" with my G25 battery. He said
> that he tested it and that it was "fine."
>
> Based on a recent article in "Aviation Consumer", I learned that the G25
> has only about 225 cold cranking amps. I noted that the G35S has 250
> cold cranking amps.
>
> (1) Is it true that I am stuck with a G25 battery and that NO OTHER
> battery in the world can go in my plane? I find that a little hard to
> believe.
>
> (2) If there are other possibilities, can someone recommend one that has
> better cold cranking amps that the G25?
>
> Thanks in advance.
>
> -Sami (N2057M, Piper Turbo Arrow III owner)
>

wrote:

>
> Since you live in central Wisconsin, you know how cold can sap a battery's
> charge, particularly if left idle for a few days. But when you say it "ran
> out of juice after 4 attempted starts" I am wondering (a) what you mean by
> no juice,

I mean that the battery would no longer turn the engine over. The
instruments were still powered.

and (b) what constitutes an "attempt."

An attempt was about 30 seconds of turning the engine over in attempt to
get it to start.

> If you mean that the
> battery is discharged to a point where the prop will no longer turn with the
> starter, that could mean a lot of things, including a defective starter.

Hmmm, how does one determine if the starter is the problem?


>
> Four prolonged start attempts with a very cold engine could easily drain a
> very cold battery. How, if at all, do you preheat?

I pre-heated with an external forced air heater under the cowl and a
warming blanket on top of the cowl. This was done for about 2 hours in
advance of the flight.

>
>
>

> I presume that you have studied the
> start procedure shown in the manual.

Yes, I followed the procedure as descrobed in the POH, including the one
you described.


By the way, thanks so much for taking the time and energy to offer your
good advice here. I am so impressed by just how generous folks are with
their willingness to share their experience and expertise on this forum.

-Sami

>
> The other thing you may wish to look at is the cable between the
> battery and the engine. I believe that a lot of the Cherokee's benefit
> from having this replaced.

That is done, but good thought!

>
> Of course, your other option is to get an APU cable for your plane.
> Used to help the Saratoga in the next tie down start his plane on
> cold mornings.

I was hoping to avoid parasitism :)

Wow...thanks.

Michelle P wrote:

> Sami,
> You can install a Concorde www.concordebattery.com CB-25, CB-25XC, RG-25
> or RG-25XC.

Gee, I wish my A&P knew this. Growl.

> 1) Four attempted starts depends on how long you were trying. Most
> starters have a 30 second continuous limit.
> using that that is 2 full minutes of cranking. That would just about be
> the limit for battery capacity.

I see. OK. So, it sounds like 4 tries is about all I can expect, no
matter what battery I get?! Guess I need to get better at this starting
thing! :)

> 2) Has your aircraft had the original battery cable (Aluminum in most
> models) with the Bogert Copper Cable kit? This improves starting speed
> and longevity.

The new cable kit has been installed.

> 3) Find a more open minded A&P Concorde recently modified the battery
> cases so they will fit in the Piper Battery Box.

Good to know. Thanks.

> 4) Place your battery on a Charger for an hour a day. Low current. A
> standard appliance timer works fine.

This may be a bit awkward. My aircarft is in a communal hanger (hmmm,
sounds communist) and they need to move it around from time to time to
get to other aircraft.

> 5) Use a battery heater.

Hmmm...I had not heard of those. Have you or anyone else on the
newsgroup had good experience with those? I wonder if I can somehow
link it to my (newly installed....just last week) Tanis heater?

>
> Michelle (A&P)
>
>

>>
>

> There was a recent article in Aviation Consumer about the
> differences between batteries.

Yes, I read the article, but I was a bit confused about which batteries
were "equivalent" to mine and could be used in my aircraft. Another
responder in this thread answered that question.

> I hope that you are preheating the engine
> before starting in the cold and if you have Tanis heaters, you can add a
> battery heater which will help a lot.

I was preheating with forced hot air from an external heater. Last
Friday, I added a Tanis heater. Does one "add a battery heater" by
getting it from Tanis and having an A&P install it?

>
> Mike
> MU-2
>
>
> "O. Sami Saydjari" > wrote in message
> ...
>
>>I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
>>recently had a situation where I ran out of juice after 4 attempted
>>starts. While I am sure that I can improve my starting technique (I am
>>a newbie for this particular plane), I would like to have a bit more
>>power in my battery, especially in very cold conditions such as we have
>>up here in central Wisconsin.
>>
>>An A&P told me recently that I am "stuck" with my G25 battery. He said
>>that he tested it and that it was "fine."
>>
>>Based on a recent article in "Aviation Consumer", I learned that the G25
>>has only about 225 cold cranking amps. I noted that the G35S has 250
>>cold cranking amps.
>>
>>(1) Is it true that I am stuck with a G25 battery and that NO OTHER
>>battery in the world can go in my plane? I find that a little hard to
>>believe.
>>
>>(2) If there are other possibilities, can someone recommend one that has
>>better cold cranking amps that the G25?
>>
>>Thanks in advance.
>>
>>-Sami (N2057M, Piper Turbo Arrow III owner)
>>
>
>
>

Great. I am certain that this level of capacity testing was not done. I
will have it done soon and let you know. Thanks.

-sami

MikeM wrote:

> "Testing" the battery means making sure it is fully charged, then
> discharging it using a known load current, timing how long it takes
> the voltage to reach 11.5V, and then computing the capacity by
> multiplying the time to reach 11.5V by the load current.
>
> According to Gill & the FAA, your battery should be up to delivering
> a load current representing all the stuff it takes to get safely on the
> ground for 30 min: this should include engine instruments, fuel gauges,
> electric gyros, radios, transponder and some lighting.
>
> A guess for the essential electrical load on your aircraft would
> be about 25A. To test the battery, connect a 12V/25A=0.48 Ohm,
> 12V*25A=300W resistor to the battery, and time how long it takes
> the battery to reach 11.5V. If your battery wont hold up this
> load for 30 min, then it should be replaced...
>
> Cranking is a separate test. An automotive service-station type of
> carbon-pile battery tester can be used to put a load of ~225A on
> the battery for 3 or so minutes. If the battery peters out short of
> 3 min, then replace it.
>
> MikeM
>
> O. Sami Saydjari wrote:
>
>> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
>> recently had a situation where I ran out of juice after 4 attempted
>> starts. While I am sure that I can improve my starting technique (I
>> am a newbie for this particular plane), I would like to have a bit
>> more power in my battery, especially in very cold conditions such as
>> we have up here in central Wisconsin.
>>
>> An A&P told me recently that I am "stuck" with my G25 battery. He
>> said that he tested it and that it was "fine."
>>
>> Based on a recent article in "Aviation Consumer", I learned that the
>> G25 has only about 225 cold cranking amps. I noted that the G35S has
>> 250 cold cranking amps.
>>
>> (1) Is it true that I am stuck with a G25 battery and that NO OTHER
>> battery in the world can go in my plane? I find that a little hard to
>> believe.
>>
>> (2) If there are other possibilities, can someone recommend one that
>> has better cold cranking amps that the G25?
>>
>> Thanks in advance.
>>
>> -Sami (N2057M, Piper Turbo Arrow III owner)
>>
>

Sami,
One battery heater supplier is:
http://www.reiffpreheat.com/Battery%20Heater.htm
Michelle

O. Sami Saydjari wrote:

> Wow...thanks.
>
> Michelle P wrote:
>
>> Sami,
>> You can install a Concorde www.concordebattery.com CB-25, CB-25XC,
>> RG-25 or RG-25XC.
>
>
> Gee, I wish my A&P knew this. Growl.
>
>> 1) Four attempted starts depends on how long you were trying. Most
>> starters have a 30 second continuous limit.
>> using that that is 2 full minutes of cranking. That would just about
>> be the limit for battery capacity.
>
>
> I see. OK. So, it sounds like 4 tries is about all I can expect, no
> matter what battery I get?! Guess I need to get better at this
> starting thing! :)
>
>> 2) Has your aircraft had the original battery cable (Aluminum in most
>> models) with the Bogert Copper Cable kit? This improves starting
>> speed and longevity.
>
>
> The new cable kit has been installed.
>
>> 3) Find a more open minded A&P Concorde recently modified the battery
>> cases so they will fit in the Piper Battery Box.
>
>
> Good to know. Thanks.
>
>> 4) Place your battery on a Charger for an hour a day. Low current. A
>> standard appliance timer works fine.
>
>
> This may be a bit awkward. My aircarft is in a communal hanger (hmmm,
> sounds communist) and they need to move it around from time to time to
> get to other aircraft.
>
>> 5) Use a battery heater.
>
>
> Hmmm...I had not heard of those. Have you or anyone else on the
> newsgroup had good experience with those? I wonder if I can somehow
> link it to my (newly installed....just last week) Tanis heater?
>
>>
>> Michelle (A&P)
>>
>>
>
>>>
>>
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

> wrote:
>The most critical (and perhaps
>counter-intuitive) thing to remember is that the mixture needs to be in full
>LEAN (i.e. cutoff) position while cranking. You need to keep your right
>hand on the mixture while you turn the key with your left hand so that you
>can quickly move the mixture to full rich as soon as the engine begins to
>fire.


Over the years, a lot of people have recommended this procedure (mostly
CFIs), but no one has explained to my satisfaction WHY this would work.
Why are you leaning the mixture at exactly the time an extra-rich
mixture is needed? After all, that is why we prime and crank with the
throttle mostly closed. I have come to believe it is one of those old
wives tails that CFIs propagate to make it appear to students that they
are "fixing" a bad start.

Since I have been working on my instrument rating through the fall and
winter, I have been doing a lot more cold weather (well, California
cold) starts than I have in past years. My starts improved immensely after
I started doing one thing: after priming about 150% of my usual
warm-weather cold-start procedure, WAIT for 30-60 sec. before cranking.
This gives the primer fuel time to evaporate in the cylinders and form a
combustible mixture. Works every time, with no pumping of the mixture
control.


Ross Oliver

"O. Sami Saydjari" > wrote in message
...
>
Does one "add a battery heater" by
> getting it from Tanis and having an A&P install it?
>

Of course everybody needs to get paid.for your battery to be warm. It
shouldn't be too difficult though.

http://www.tanair.com/accessories.html#BATTERYHEATERS

Mike
MU-2

Ross Oliver wrote:
> > wrote:
>
>>The most critical (and perhaps
>>counter-intuitive) thing to remember is that the mixture needs to be in full
>>LEAN (i.e. cutoff) position while cranking. You need to keep your right
>>hand on the mixture while you turn the key with your left hand so that you
>>can quickly move the mixture to full rich as soon as the engine begins to
>>fire.
>
>
>
> Over the years, a lot of people have recommended this procedure (mostly
> CFIs), but no one has explained to my satisfaction WHY this would work.
> Why are you leaning the mixture at exactly the time an extra-rich
> mixture is needed? After all, that is why we prime and crank with the
> throttle mostly closed. I have come to believe it is one of those old
> wives tails that CFIs propagate to make it appear to students that they
> are "fixing" a bad start.
>

Well, (1) it's what my POH says to do, and (2) it seems to work.

Remove SHIRT to reply directly.

Dave

Often overlooked are the master and starter solenoids. These things
get burned contacts and they begin to present a resistance that shows
up as reluctant cranking. A voltmeter placed across the solenoids' big
terminals should show 13 volts when the system is off, and NO voltage
when it's on (or cranking). Any voltage while the solenoid is closed
indicates resistance across the contacts. Even a small amount of
resistance at high current flows will cause significant voltage drop
(E=I*R; A .02 ohm resistance at 200 amps gives a 4-volt drop). Check
the cable connections the same way. Check both the master and starter
solenoids with the engine cranking.
An ohmmeter isn't really good enough to detect bad solenoid
contacts. The resistances are small, and increase with heat caused by
electical flow. An ohmmeter won't detect the heated resistance.


Dan

(Dan Thomas) writes:

>Often overlooked are the master and starter solenoids. These things
>get burned contacts and they begin to present a resistance that shows
>up as reluctant cranking. A voltmeter placed across the solenoids' big
>terminals should show 13 volts when the system is off, and NO voltage
>when it's on (or cranking).

Actually, get the meter probes on the WIRES, as the path
look like this:


wire-lug-nut-bolt-solenoid-bolt-nut-lug-wire

By measuring from the wire to the wire, you confirm that the lug's
well-connected to the wire, the nut is cleanly contacting the lug,
etc....

You likely want an analog meter (remember those) as it will be hard to
read bouncing digits on a DVM.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

Dan,
No voltage across the contact is unrealistic. O.5 volt is considered to
be the acceptable limit.
If you replace the master and starter solenoids. Have your A&P install
diodes reverse to the flow across the contractor terminals. The will
prevent the contact from arcing when they disengage. It is the contact
arcing that increases the resistance and causes the voltage drop. 0.5
volts across the contacts is 0.0013 ohms.
Michelle

Dan Thomas wrote:

>Often overlooked are the master and starter solenoids. These things
>get burned contacts and they begin to present a resistance that shows
>up as reluctant cranking. A voltmeter placed across the solenoids' big
>terminals should show 13 volts when the system is off, and NO voltage
>when it's on (or cranking). Any voltage while the solenoid is closed
>indicates resistance across the contacts. Even a small amount of
>resistance at high current flows will cause significant voltage drop
>(E=I*R; A .02 ohm resistance at 200 amps gives a 4-volt drop). Check
>the cable connections the same way. Check both the master and starter
>solenoids with the engine cranking.
> An ohmmeter isn't really good enough to detect bad solenoid
>contacts. The resistances are small, and increase with heat caused by
>electical flow. An ohmmeter won't detect the heated resistance.
>
>
> Dan
>
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

On 27-Jan-2004, "O. Sami Saydjari" > wrote:

>> But when you say it "ran out of juice after 4 attempted starts" I am
>> wondering (a) what you mean
> > by no juice,
>
> I mean that the battery would no longer turn the engine over. The
> instruments were still powered.
>
> >and (b) what constitutes an "attempt."
>
> An attempt was about 30 seconds of turning the engine over in attempt to
> get it to start.

Well, from what you say your (cold) battery is able to crank the engine for
a total of about 2 minutes before it gets run down. That doesn't sound too
bad to me. You should note, however, that cranking non-stop for 30 seconds
is way too long. You are probably over-heating your starter. Anyway, the
real problem isn't your battery but that your (preheated) engine failed to
start. Properly preheated, it SHOULD start with no difficulty. I would
strongly suspect the impulse gear in the left mag. Or you may be flooding
the engine because of improper start technique (a preheated engine needs
only a little bit of priming) or because of a mechanical problem with the
fuel injection system. After cranking unsuccessfully for a bit, try the
"flooded engine" start technique. (Electric fuel pump OFF, Throttle FULL
OPEN, mixture to IDLE CUT-OFF.)


>
> > If you mean that the battery is discharged to a point where the prop
> > will no longer turn with
> > the starter, that could mean a lot of things, including a defective
> > starter.
> >
>
> Hmmm, how does one determine if the starter is the problem?

That doesn't sound like your problem, but a starter would be suspect if it
failed to vigorously crank the engine with a freshly charged battery. Of
course, that problem could be caused by other problems such as loose
electrical connections or corroded battery terminals.


-Elliott Drucker

Thanks for the informed input. The resistance across the contacts
would get larger as the solenoid ages, and there are a lot of old
solenoids out there. We had a starter solenoid weld itself closed and
burn out the starter. New starter $1200, new solenoid $28. They're
worth replacing.
Two other items that can cause hard starting in the cold: (1)The
impulse couplings on the mags can get sludged up somewhat, and when
cold they won't give the sharp snap needed to make a spark. (2)If the
engine isn't preheated and the weather is cold enough, the first
combustion cycles will create enough water vapour in the cylinders to
frost the sparkplug electrodes and short them. My old A-65 is famous
for this. You get a very brief run and then it dies, and no amount of
fooling with it will make it go.

Dan

Michelle P > wrote in message >...
> Dan,
> No voltage across the contact is unrealistic. O.5 volt is considered to
> be the acceptable limit.
> If you replace the master and starter solenoids. Have your A&P install
> diodes reverse to the flow across the contractor terminals. The will
> prevent the contact from arcing when they disengage. It is the contact
> arcing that increases the resistance and causes the voltage drop. 0.5
> volts across the contacts is 0.0013 ohms.
> Michelle
>
> Dan Thomas wrote:
>
> >Often overlooked are the master and starter solenoids. These things
> >get burned contacts and they begin to present a resistance that shows
> >up as reluctant cranking. A voltmeter placed across the solenoids' big
> >terminals should show 13 volts when the system is off, and NO voltage
> >when it's on (or cranking). Any voltage while the solenoid is closed
> >indicates resistance across the contacts. Even a small amount of
> >resistance at high current flows will cause significant voltage drop
> >(E=I*R; A .02 ohm resistance at 200 amps gives a 4-volt drop). Check
> >the cable connections the same way. Check both the master and starter
> >solenoids with the engine cranking.
> > An ohmmeter isn't really good enough to detect bad solenoid
> >contacts. The resistances are small, and increase with heat caused by
> >electical flow. An ohmmeter won't detect the heated resistance.
> >
> >
> > Dan
> >
> >
>
> --
>
> Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P
>
> "Elisabeth" a Maule M-7-235B (no two are alike)
>
> Volunteer Pilot, Angel Flight Mid-Atlantic
>
> Volunteer Builder, Habitat for Humanity

(2)If the
> engine isn't preheated and the weather is cold enough, the first
> combustion cycles will create enough water vapour in the cylinders to
> frost the sparkplug electrodes and short them. My old A-65 is famous
> for this. You get a very brief run and then it dies, and no amount of
> fooling with it will make it go.
>

Very interesting. I never heard of that. Is it common? I did note
that the engine did sputter briefly on my first try. I wonder if it was
not adequately preheated (used forced air for only about 2 hours).
Well, I have an A&P looking at it over the next couple of days. I will
report his findings. Thanks for all the sage advice.

-Sami

Wow, you'd think if the starter stuck on, the first thing you'd
do is reach for the master! Quickly! Seen that happen on one
plane actually, when someone turned on the master, the prop
started spinning.

Paul

"Dan Thomas" > wrote in message
om...
> We had a starter solenoid weld itself closed and
> burn out the starter.

(Ross Oliver) wrote in message >...
> Over the years, a lot of people have recommended this procedure (mostly
> CFIs), but no one has explained to my satisfaction WHY this would work.
> Why are you leaning the mixture at exactly the time an extra-rich
> mixture is needed? After all, that is why we prime and crank with the
> throttle mostly closed. I have come to believe it is one of those old
> wives tails that CFIs propagate to make it appear to students that they
> are "fixing" a bad start.

Mainly because if the electric boost pump is running and the mixture
control is in any position other than idle cut-off fuel is being
sprayed into the engine through the injection system.

You want to add slightly more than enuff fuel to get the engine
started, then shut off the flow of fuel (mixure to ICO), it'll lean
slightly when cranking (and after starting, with the mixture back, no
more is being added), reach the proper ratio to start-and-run, then
shove the mixture ahead to add metered fuel to keep it running.

No OWT's-just the operating parameters/limitations of "modern"
continuous-flow fuel injection.

TC

Student and instructor didn't realize the solenoid had stuck after
starting the engine. There was a bit of "funny noise" in the headsets,
but they didn't get alarmed until they saw the ammeter indicating a
massive charge rate. Engine noise will drown out most starter noise,
especially if the starter drive disengages with engine speedup as an
O-200 does.
One bush operator I know of installs a red indicator light on the
panel, wired across the starter feed, to alert the pilot to a stuck
starter. It isn't rare.
We always make sure the prop path is clear when turning on the
master. It's not wise, either, to hangar airplanes with wings
overlapping props.

Dan

"Paul Sengupta" > wrote in message >...
> Wow, you'd think if the starter stuck on, the first thing you'd
> do is reach for the master! Quickly! Seen that happen on one
> plane actually, when someone turned on the master, the prop
> started spinning.
>
> Paul
>
> "Dan Thomas" > wrote in message
> om...
> > We had a starter solenoid weld itself closed and
> > burn out the starter.

My plane has a red light which comes on when the starter
solenoid is engaged. One of the after startup checks is
"Starter warning light out". This is in a Scottish Aviation
Bulldog, but I use a PA-38 checklist and I belive that's
in the checklist. Mine has stuck once. Another press on
the starter button freed it. Never had any problems since.

Paul

"Dan Thomas" > wrote in message
om...
> One bush operator I know of installs a red indicator light on the
> panel, wired across the starter feed, to alert the pilot to a stuck
> starter. It isn't rare.

Here is an update on the battery saga. I had a different A&P do a
capacity test. He advised me that my battery fell below some reaonsable
threshold voltage within seconds. Time for a new battery. Arg, I am so
frustrated with the other A&P for not taking the time to do a real test.

Oh, and the previous A&P advised me that I had a Gill G25 battery. So,
I ordered a Concorde RG 25XC to get the added cranking power. Well,
unfortunately, it turns out I have a Gill G35, so they ordered the wrong
battery and it would cause a 2-3 day delay in the replacement to order
the RG-35AXC. So, now I am going with a new Gill 35.

-Sami
N2057M Piper Turno Arrow III

O. Sami Saydjari wrote:
> I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
> recently had a situation where I ran out of juice after 4 attempted
> starts. While I am sure that I can improve my starting technique (I am
> a newbie for this particular plane), I would like to have a bit more
> power in my battery, especially in very cold conditions such as we have
> up here in central Wisconsin.
>
> An A&P told me recently that I am "stuck" with my G25 battery. He said
> that he tested it and that it was "fine."
>
> Based on a recent article in "Aviation Consumer", I learned that the G25
> has only about 225 cold cranking amps. I noted that the G35S has 250
> cold cranking amps.
>
> (1) Is it true that I am stuck with a G25 battery and that NO OTHER
> battery in the world can go in my plane? I find that a little hard to
> believe.
>
> (2) If there are other possibilities, can someone recommend one that has
> better cold cranking amps that the G25?
>
> Thanks in advance.
>
> -Sami (N2057M, Piper Turbo Arrow III owner)
>

"O. Sami Saydjari" > wrote in
:

> Oh, and the previous A&P advised me that I had a Gill G25 battery.
> So, I ordered a Concorde RG 25XC to get the added cranking power.
> Well, unfortunately, it turns out I have a Gill G35, so they ordered
> the wrong battery and it would cause a 2-3 day delay in the
> replacement to order the RG-35AXC. So, now I am going with a new Gill
> 35.

A lot of smaller A&P's don't actually have a load tester (or much of
anything else in the way of test equipment). Unfortunate, but that's
the way it is.

FWIW, one turbo-Arrow III owner to another, I really like the RG-35
series, but haven't had very good luck with them in my Arrow (in spite
of carefully checking voltages, copper cables, etc.). Other folks have
results that tends to follow one of two patterns. Either, like me, the
Concorde RG batteries are really good for only a few months and limp
along for another six or so; or they seem to work great for years and
years. [And I have seen what seems to be a breakdown between the two
results along the lines of the type of plane.... but don't know why.]

The wet cell type (like the G35 you are getting) seem to work better for
me. OTOH, I keep trying -- I now have a new RG-35AXC in there, and it
DOES seem to be lasting longer than the RG-35 or RG-35AX did (which
wasn't all that long).

I know you haven't had the Arrow long. It's a great plane and I think
you will enjoy it a lot. But you might want to start getting to know
more about the hardware. The logbooks can make some very interesting
reading (especially between the lines) and will tell you things like
what kind of battery you have, and when your vacuum pump was last
replaced, or the last time your AI was overhauled. Fun *and* useful
reading for a cold winter evening.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------