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Starting issues - battery or not battery ?

Erimo

Well Known Member
Recently I changed the PC680 battery after repeated starting problems. She was less than 2 years and 150 hours old. The starter only worked if the battery had just been fully charged. Otherwise I heard the starter solenoid click but no starter and propeller motion.
With the new battery, the engine started immediately for 1 month (3 hours flight every weekend) and then again yesterday the same failure as with the old battery, a day after a 90-minutes flight. After half an hour of charging, the starter operates again and the engine starts instantly.
I do not see how the battery alone can explain this failure.
Actually the engine starts if the battery is fully charged, but even a little discharged the starter should turn slower ?
Do you have any ideas ?
 
Check the alternator output?

Bonjour Eric,


Did you recently check the output voltage from the alternator?


If too low, that might explain a weak battery. The new one would probably have enough charge for a few starts on a low recharge rate.??
 
I'd start by looking at your alternator output voltage. The PC brand of sealed cell batteries likes to see a least 14.2 volts in flight to really charge. What is your buss voltage in flight? If it's down around 13.6 volts these batteries will not charge much.
 
I would look closely at the starter. At about 70 hours, my starter on my RV-14A's stock IO-390 failed. The starter contact on the firewall would click, but the starter solenoid would not engage. I sent the starter to Sky-tec and they agreed the starter was to blame. On replacement, they suggested I replace the stock 149-12XLT (similar to the previously stocked 149-12LS) with the 149-12NL. There was a bit of modification to be made, but that starter has worked well so far. There are a couple of RV-14A blogs that cover the modifications.
 
Which starter? The standard lightweight 149LS has known issues with the solenoid in the starter failing or intermittent (mine was). Skytec replaced my starter with the beefier 149NL by request and all happy again.
 
Also check the lugs on the wires for corrosion and check the connection from the wire to the terminal. Poor wire connections would give the same symptoms as a undercharged battery.
 
Also check the lugs on the wires for corrosion and check the connection from the wire to the terminal. Poor wire connections would give the same symptoms as a undercharged battery.

This! But don't forget to check ALL connections. Ground to engine, ground to firewall, "+" to battery, "+" to starter, and ALL connections between the "+" battery post
and the "-" battery post.
 
Similar problem in mine turned out to be the starter relay (at about 250 hrs). I bought a new battery too and it's back on the shelf waiting for a real failure...The original PC680 is 4 yrs old...

All other stock components, alternator, starter, solenoid, connections, all ok after 4 yrs on the ramp.
 
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Recently I changed the PC680 battery after repeated starting problems. She was less than 2 years and 150 hours old. The starter only worked if the battery had just been fully charged. Otherwise I heard the starter solenoid click but no starter and propeller motion.
With the new battery, the engine started immediately for 1 month (3 hours flight every weekend) and then again yesterday the same failure as with the old battery, a day after a 90-minutes flight. After half an hour of charging, the starter operates again and the engine starts instantly.
I do not see how the battery alone can explain this failure.
Actually the engine starts if the battery is fully charged, but even a little discharged the starter should turn slower ?
Do you have any ideas ?

Your symptoms point to a charging problem. The fact that ground charging works well each time, but won't work after a flight, where the Alt should have recharged the depleted energy, points to a problem in your airplanes charging system.

Charge battery and confirm voltage above 12.8, then fly for an hour. Two hours after flight, measure the battery voltage. If below 12.8 two hours after shutdown, your charging system is not working properly.
Larry
 
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I'd start by looking at your alternator output voltage. The PC brand of sealed cell batteries likes to see a least 14.2 volts in flight to really charge. What is your buss voltage in flight? If it's down around 13.6 volts these batteries will not charge much.

Hi Eric and Bob,

On last flight (last sunday) the ALT output was 14.3V.
 
Which starter? The standard lightweight 149LS has known issues with the solenoid in the starter failing or intermittent (mine was). Skytec replaced my starter with the beefier 149NL by request and all happy again.

I don't know the starter's reference. Next time I remove the cowls I'll watch that.
If I had to replace the starter, who I'll have to contact ?
 
Also check the lugs on the wires for corrosion and check the connection from the wire to the terminal. Poor wire connections would give the same symptoms as a undercharged battery.

Yes, I'll check all wires connection. But I'm sure there is no corrosion.
I think to check too, the impedance between solenoid and starter, and voltage between them while starting.
 
This! But don't forget to check ALL connections. Ground to engine, ground to firewall, "+" to battery, "+" to starter, and ALL connections between the "+" battery post
and the "-" battery post.

Yes, of course. Thanks.
 
Similar problem in mine turned out to be the starter relay (at about 250 hrs). I bought a new battery too and it's back on the shelf waiting for a real failure...The original PC680 is 4 yrs old...

All other stock components, alternator, starter, solenoid, connections, all ok after 4 yrs on the ramp.

It's why I'll check voltage and power at starter solenoid output during a starting.
 
Your symptoms point to a charging problem. The fact that ground charging works well each time, but won't work after a flight, where the Alt should have recharged the depleted energy, points to a problem in your airplanes charging system.

Charge battery and confirm voltage above 12.8, then fly for an hour. Two hours after flight, measure the battery voltage. If below 12.8 two hours after shutdown, your charging system is not working properly.
Larry

Today I checked the battery voltage after 3 days on ground : 13.05 V. After 45 mn of recharge : 13.75 V (with a Optimate saving charger).
I''check before and after flight the next time (this WE I hope).
 
Today I checked the battery voltage after 3 days on ground : 13.05 V. After 45 mn of recharge : 13.75 V (with a Optimate saving charger).
I''check before and after flight the next time (this WE I hope).

Presuming that you flew it 3 days ago and left the plane without charging it on the ground, then came back and measured batt voltage at 13V. If that is the case, your plane is charging just fine while flying. Issue is likely something with the Starting circuit. That could be cables or their connections, starter solenoid, the starter, or the ground connection from the eng block to airframe/battery.

Most likely culprits are the starter solenoid and corroded or loose connections. Might start by measuring voltage drop at: Input of solenoid, output of solenoid and starter. That may point you in the right direction.

Larry
 
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This! But don't forget to check ALL connections. Ground to engine, ground to firewall, "+" to battery, "+" to starter, and ALL connections between the "+" battery post
and the "-" battery post.
AND the wire on the starter itself to the starter-mounted solenoid. AND the crimps not just the terminals. On my SkyTec starter I had a bad crimp on that short wire that caused a similar problem.
 
Originally Posted by Mel:
----------------------------------------------------
This! But don't forget to check ALL connections.....
-----------------------------------------------------

Having experienced similar symptoms, I'd look carefully at the starter relay (the one on the firewall). It's the one "connection" which doesn't lend itself to visual inspection...(until you take it apart :)
 
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Two similar issues I’ve experienced.

As others have mentioned check all your connections.
I had nut on the fat wire on the downstream side of the starter contactor come loose. It arced and welded itself. So it still worked but super patchy.

The other one which I have seen a few people do (myself included) is inadvertently wire the voltage sense on an external alternator regulator to the battery bus.
That regulator will draw a tiny current (about 20mA) with everything shut off.
Obv not a problem if you fly regularly but if you leave it a week or two..
Easy to test. See if there’s any parasitic drain on the battery with the master off.

Cheers.
 
Our starter troubles

We had a Skytec LS starter that was becoming intermittent. Especially after the first flight so we assumed it was some sort of heat-related issue. We could hear a relay clunk but no sign of rotation from the prop. Difficult to troubleshoot at first but was becoming worse with time.

The first thing we did, in addition to checking connections and voltages, was replace the firewall mounted start relay. No joy.

After taking off the snorkel which was preventing us from seeing the starter and solenoid well discovered the rivet that holds the little plate for the small ground signal to engage the starter was loose.

Update on part number for this solenoid which was earlier referenced as a borg warner BWD S5613. NAPA now shows this as a ECH ST421 which is cross referenced to early 2000's Crown Victoria's as well as the Ford Pickups.
 
Thanks

Thank you for all your advises.

I just found the starter relay connector nut to starter wire not completely tight.
So the split washer was not enough crushed.

I don't know if the issue is definitively fixed, but any start failure since this tightening.

:)
 
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