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Battery Replacement and Cold Cranking Amps
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) |
#2
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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 |
#3
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"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. |
#4
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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 |
#5
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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) |
#6
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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...." |
#7
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"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) |
#8
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#9
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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 |
#10
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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) |
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