Electical power outage on 182RG
Electrical power outage on 182RG
I would be grateful for your help answering two questions about a recent electrical outage I experienced in a 1979 182 RG.
Following occur
I flew my 182RG for approximately two hours in Florida without any issues.
Then, I landed the plane at a non-towered airport during a practice instrument approach.
Then, I taxied to the active runway and took off again.
An electrical outage occurred at some 600 feet AGL. No prior warning of electrical issues via low voltage or amp monitors
The Garmin GTX750, GNS430, GTX345, GFC 500, etc. were without power. The engine still worked.
Immediately, I landed the plane again at the airport via the regular pattern.
During the short flight after the power outage
o I confirmed that none of the circuit breakers had been activated.
o I lowered the flaps and the landing gear. There was sufficient power to operate these – albeit flaps took a long time to decent, and there was insufficient power to enable landing gear to lock in position fully.
· After landing, I established that the battery showed 20.9v volts, and a lot of its fluid contents had evaporated. It is an old battery type—not sealed.
I have at least two questions.
· If a battery fails due to liquid content evaporating (but still retained some 20v charge), should the deterioration have been detected by low voltage or amp monitors? In other words, should I have had an advanced warning of the electrical problem?
· If a battery fails in a 182, should the alternator and the wiring design have enabled the plane to be electrically powered and avoid the whole power outage outcome? In other words, should the 182, in flight, be able to operate on just the alternator with no battery?
Comments
Good questions. I'm assuming you've put a new battery in.... How old was the old battery and did you service it at the last annual? And how long ago was the annual?
Also, there may be other issues with your plane that revolve around the alternator and voltage regulator.
Have you consulted with your mechanic and your service manual?
Scott Sherer
Wright Brothers Master Pilot, FAA Commercial Pilot
Aviation Director, Cessna Owners Organization Forum Moderator and Cessna Owners Author.
Need help? Let me know!
Hi Scott
Thanks for the quick response. The battery was +3 years old. It was serviced in the last three months to ensure sufficient fluid and had and held an appropriate charge. Since the power outage, I have replaced the battery.
I have consulted with my mechanic, plane’s service manual and avionics shop about what occurred. However, I am still eager to learn more and cannot obtain sufficient answers to some questions I have. I’d like to understand.
A) Whether there is potentially an issue with my voltage or amp monitors. Hence my question, about if a battery fails due to liquid content evaporating (but still retained some 20v charge), should the deterioration have been detected by low voltage or amp monitors? If there should have been a warning, we know to explore whether electrical monitors are working correctly. What is your view on the answer to the question raised?
B) We are looking at the alternator to check that it is working correctly. I would nevertheless like to understand, if a battery fails in an 182, should the alternator and the wiring design have enabled the plane to be electrically powered and avoid the whole power outage? If there should be sufficient electrical power in flight, with just the alternator operating, then we also know to explore the electrical wiring. What is your view on the answer to the question raised?
Regards
David
First my disclaimer, I am not an A&P nor IA. But I am the 15 year owner of a R182 who flys a good bit a year. So take that for what it’s worth. I have had a complete electrical failure as the nose gear came off the runway. As a result, I learned that it was due to an internal battery failure. The battery on an airplane like ours is absolutely required all the time for the system to function. Unlike an old car where once started the alternator does the rest. Regarding should you have detected it? Hard to say. In my experience I have rarely had any warnings prior to electrical issues. In the case of my complete failure, no warning. In fact the battery even showed correct charging and correct charge when checked with a multimeter, it just happened to be an internal failure that showed up when the demand of the hydraulic pump was applied to the system. Replace your battery and go from there. Hope this helps a little.
A battery at 20 volts is 'dead', fully discharged, and the alternator is off line or failed.. If the battery is left with the plates exposed, it can have a shorted cell. The alternator will try charging it but would only get to 22-24 volts... this will cause the battery to get hot as well as overload the alternator.
Did the voltage get to 28 volts after the new battery was installed and the engine running ? If it is, then the old battery had failed.
I would think the question is where and how did the battery boil off? Was your amp meter or voltage gauge showing an over charge? I’d think your voltage regulator and or charging system needs to be checked and or replaced. If your battery is boiled that would be my first place to look. You may just fry another battery if you don’t
great comment !
The regulator should be set to 28.5 to 29.0 volts, and there should be a 'blast tube' from the upper baffles, to provide cooling air to the alternator.
Overcharging, volts greater than 30 volts will cause out-gassing of hydrogen in a flooded cell battery. AGM batteries are a bit more tolerant .
Hi
Thanks for all the helpful comments.
In response to the observations made
1) we have replaced the battery
2) agreed we need to check the voltage regulator and charging system to ensure it is working properly
3) Amp meter or voltage gauge did not show an overcharge before power outage
4) we plan to test, on the ground with the engine running, the battery to ensure it is charging appropriately and that electrical monitors work
regards
David
David,
Please reply with the info on getting your electrical system volts ok...battery [ a Concorde ?], alternator working ok and setting the voltage regulator.
We all benefit from how to get all our aircraft 'stuff' working ok.!
I’d buy a cheap harbor freight volt meter that plugs into your cigar lighter port if you have one. In my old 172 i had it plugged in pretty regularly when i flew.
i believe that the amp meter tells you your generator or alternator is working. The volt meter tells you your battery status.
If, he really had cooked the acid out of the battery, either he has a shorted cell calling for full charge, or the alt system is getting full field and charging that sucker like crazy. That should show up on the cheepo cessna ammeter with the needle on the charge side ALL the time, not centered.
My take is he had a bad battery. Since he hasn't replied in a while,, must be working ok!
Yes, need bat for alternator to work. Alternators need field voltage to get it going. Once going, you can turn the bat off, but if you kill the alt, need bat back on line to restart the alt.
IA 47yr A&P DAL A/C Inspector 172n
This note summarises the findings into why an electrical outage occurred in my 1979 Skylane 182 RG at some 600 feet AG, with no prior warning of electrical issues from either low voltage or amp monitor.
Thanks for all the helpful comments about the possible causes of the outage. Our findings are consistent with the comments made.
Causes
Regards
David
An alternator will only deliver as much current to the battery as the battery is asking for. Unless the alternator voltage exceeded limits AND the overvolt relay didn't open, there's not a way for the alternator to damage the battery.
However, there are plenty of ways for a battery to fail which can cause it to fail and overheat.