Electrical Failure
Posted: Sat May 04, 2024 4:20 am
by pvs
Any help much appreciated
Started my Onex with no issues, All systems checked, EMS, Efis, Radio Strobe all worked normally EMS indicated 12.8 volts in system. Did a run up normal after couple minutes EMS indicated a low voltage warning then electrical system shut everything down. I recharged the battery. Next day same thing happened. Checked the battery terminal indicated 2.08 volts, disconnected the battery after recharge Voltage on the Earthx battery was 13.2 volts with good load resistance. All connections seem tight no corrosion observed. All fuzes were good. Any suggestions were to start???
Re: Electrical Failure
Posted: Sat May 04, 2024 9:28 am
by Bryan Cotton
Hey pvs, welcome to the forum. You don’t say what engine you have but I’m thinking AeroVee is a good guess. There is not much to the electrical system. You need good magnets, a good stator, a good voltage regulator, and it needs to be hooked up.
When I was troubleshooting I first checked the open loop stator voltage. I think the desired value is in one of the links below. Next I went through a few VRs and the John Deere unit is awesome.
Good luck!
Re: Electrical Failure
Posted: Sat May 04, 2024 9:32 am
by BRS
Need much more information.
At first glance it seems your charging system is off-line. So tell us about your installation. What engine & alternator? How is it wired etc?
I’d expect you checked the obvious (Alt-switch on, all fuses in the system, wires secure)
EarthX low volts is a BMS safety feature. It disconnects the cells when they get too low. A norminal voltage for a charged EX battery is 13.3.
Re: Electrical Failure
Posted: Sat May 04, 2024 9:34 am
by Bryan Cotton
23-27 VAC open loop on the stator at 3000 RPM.
http://www.sonexbuilders.net/viewtopic. … age#p56060
Re: Electrical Failure
Posted: Sat May 04, 2024 12:26 pm
by pvs
Thanks to all for the reply. it is an aerovee and is wired per instructions from sonex. it has a mil stratomaster Ems. when I disconnect the negative battery cable battery indicates 13.2 volts. Then after running the engine when the electrical system shuts down the battery indicates 2.08 volts. Disconnect the ground of the battery it indicates 13.2. checked for possible shorts in the can’t locate any. How would a charging system come off line after operating normally for about ten minutes. Ant thoughts Thank you
Re: Electrical Failure
Posted: Sat May 04, 2024 3:22 pm
by pvs
Bryan thank you so much for the links, get to the airport Monday start the quest.
Re: Electrical Failure
Posted: Sun May 05, 2024 9:18 am
by Scott Todd
Do the math. If it drops that much after a few minutes, its NOT the charging system. Without knowing more, lets look at a simple example. My two AeroVee’s with both ignitions, lights, and instruments draws around 7-8 amps. If I turn the Secondary ignition off, it goes down to around 1-2 but that’s not important here. So for easy math, lets we round it up to 10 and guess the battery is a 20 amp-hour battery, it should run everything for two hours. Starting takes a little out of it. So if its charged, we start the engine and run it for less than half hour, without out a charge system, the battery should be at least half charged. I guess that would be around 11-12 volts. NOT 2.08 volts. Borrow and toss an Odyssey in there and see what happens.
I know of about 20 experimental airplanes around me that use Odyssey. A few guys have played with the EarthX ones. The Odyssey guys replace them every three years because the Arizona summer just kills them. Most guys use the 680 in everything from Cubs to 6 cylinders. I use the slightly smaller one in my 3 airplanes and they always make it 3 years. Its $100 but I NEVER worry about them and they always work.
Re: Electrical Failure
Posted: Sun May 05, 2024 1:53 pm
by daleandee
Scott Todd wrote:I know of about 20 experimental airplanes around me that use Odyssey. A few guys have played with the EarthX ones. The Odyssey guys replace them every three years because the Arizona summer just kills them. Most guys use the 680 in everything from Cubs to 6 cylinders. I use the slightly smaller one in my 3 airplanes and they always make it 3 years. Its $100 but I NEVER worry about them and they always work.
I’m hesitant to enter this conversation because I’m not a fan of EarthX batteries and I seem to get excortiated whenever I mention that fact. I agree with Scott here in that putting an Odyssey battery in would likely solve the problem.
EarthX batteries have a BMS that will shut the battery off under certain conditions to protect the battery. In a plane that doesn’t require power to run that might be acceptable (still not to me). I don’t use EarthX because my Corvair airplane requires power to run and having the electrical system shut down isn’t something I can take a chance on.
You need to know what the AC output of the alternator is and what the DC output of the regulator is. I use and recommend the Yanmar voltaage regulator that was referenced earlier.
As for the Odyssey PC-680 only lasting three years … my experience shows that not to be true. I do buy a new one every three years for my plane (it is electrically dependant so I keep a fresh battery in there). I have placed the older batteries from the airplane in my 1974 VW Beetle, my zero-turn lawn mower, and other equipment. I have one that is ten years old and it’s getting a bit on the fritz but most of the ones I have seem to last at least eight years or so and it does get hot here in Carolina too. 8~)
Dale
3.0 Corvair/Tailwheel
Re: Electrical Failure
Posted: Mon May 06, 2024 4:47 pm
by Scott Todd
I didn’t say they only last three years. I said we replace them every three years, like Dale. I’ve only seen them fail after 4, 5, or even 6 years. But as a precaution, most just replace them. And as a reminder to other viewers, its 120F or more in our hangars in the summer. The few EarthX guys have more battery issues than ALL the Odyssey batteries combined.
Re: Electrical Failure
Posted: Mon May 06, 2024 6:57 pm
by Skippydiesel
Fascinating! The focus on Odyssey, why? They are only a lead acid battery, very much like what you can put in your motorcycle.
If you want to use a lead acid open your marketing befuddled minds and do the research - plenty of good motorcycle batteries out there with all the necessary specifications to make a good choice and at much lower purchase cost.
Re: Electrical Failure
Posted: Tue May 07, 2024 8:01 pm
by WaiexB22
daleandee wrote:
EarthX batteries have a BMS that will shut the battery off under certain conditions to protect the battery. In a plane that doesn’t require power to run that might be acceptable (still not to me). I don’t use EarthX because my Corvair airplane requires power to run and having the electrical system shut down isn’t something I can take a chance on.
Dale - Are you running one battery or two?
Re: Electrical Failure
Posted: Tue May 07, 2024 9:17 pm
by daleandee
WaiexB22 wrote:
daleandee wrote:
EarthX batteries have a BMS that will shut the battery off under certain conditions to protect the battery. In a plane that doesn’t require power to run that might be acceptable (still not to me). I don’t use EarthX because my Corvair airplane requires power to run and having the electrical system shut down isn’t something I can take a chance on.Dale - Are you running one battery or two?
One - Odyssey PC680
Dale
3.0 Corvair/Tailwheel
Re: Electrical Failure
Posted: Tue May 07, 2024 9:27 pm
by WaiexB22
Thanks!
Re: Electrical Failure
Posted: Tue May 07, 2024 9:40 pm
by daleandee
Just today I replaced a Odyssey PC680 battery in a Corvair powered Zenith 701 for a friend. His battery was eight years old (2016) and still cranking the plane just fine. We were assisiting the A&P with the condition inspection. I had suggested that the battery be replaced because several months ago he left the ignition on overnight and completely killed that battery. After recharging, it performed flawlessly but for the sake of safety (the Corvair requires power to run) a fresh battery was installed.
For those that apparently do not know the difference between a flooded lead acid battery and a Absorbent Glass Mat battery I suggest doing a bit of research and see why AGM is much better and then consider why Odyssey batteries receive a very high grade in the AGM department. Are there cheaper batteries that I can buy for my airplane? Nope, nada, no way …
https://www.autonationmobileservice.com … lead-acid/
Dale
3.0 Corvair/Tailwheel
Re: Electrical Failure
Posted: Tue May 07, 2024 11:39 pm
by Skippydiesel
Dale FYI:
Every motorcycle battery that I used in my last aircraft (current one came with an EarthX already fitted) was a motorcycle AGM.
All gave excellent service and at a very competitive price.
Anything sold under/with the name AIRCRAFT/AVIATION is at a premium cost.
Sometimes this is deserved but more often not.
Sometimes there is no choice (certified aircraft) but where there is you may be pleasantly surprised at what other cost effective options there are in the marketplace - you just have to be willing to check it out (do your homework ie know the dimensions of the battery, minimum CCA’s, terminal type/orientation/ etc before you start, only look at sites with full specification including weight))
Re: Electrical Failure
Posted: Wed May 08, 2024 9:59 am
by GordonTurner
I have installed dual Shorai LiFePo batteries in my Corvair powered Waiex. I purchased them directly from Shorai and found a 15% off discount code online somewhere that worked. Either one can crank the motor, and there is provision to parallel them if needed. Normally, one or the other is sitting completely isolated from the electrical system ready to directly power the secondary ignition if something happens to the electrical system/other battery/primary ignition.
The batteries are super light, not cheap but reasonably priced, and quality seems high. And no BMS to shut them down (yes, that means you better not forget to turn off your master). I also installed a thermocouple on each battery so I expect to get a warning if things aren’t going well.
Re: Electrical Failure
Posted: Wed May 08, 2024 12:25 pm
by GordonTurner
If anyone is interested, here’s a 10% coupon. Better than a poke in the eye with a sharp stick as they say 
Re: Electrical Failure
Posted: Wed Jun 05, 2024 4:14 pm
by Art Tiller
I have a similar issue with my new to me Sonex AeroVee. I have had just a few flights in my airplane. The last couple of flights my MGL Stratomaster went blank on me taxing in to my hangar. Did a little trouble shooting and have decided that my 8 year old EarthX is due for replacement.
So, if my battery box will accept it, I may buy an Odyssey PC680 AGM. $155 vs $699 for the EarthX. Changing it out every three years seems like a good deal.
Re: Electrical Failure
Posted: Wed Jun 05, 2024 5:18 pm
by Bryan Cotton
Art Tiller wrote:So, if my battery box will accept it, I may buy an Odyssey PC680 AGM. $155 vs $699 for the EarthX.
The EarthX ETX680 is $379 at ACS.
https://www.aircraftspruce.com/catalog/ … key=402696
I’m still an EarthX fan. Weight is the enemy.
Re: Electrical Failure
Posted: Wed Jun 05, 2024 6:33 pm
by daleandee
Bryan Cotton wrote:
Art Tiller wrote:So, if my battery box will accept it, I may buy an Odyssey PC680 AGM. $155 vs $699 for the EarthX.
The EarthX ETX680 is $379 at ACS.
https://www.aircraftspruce.com/catalog/ … key=402696I’m still an EarthX fan. Weight is the enemy.
I’m solidly in the Odyssey PC-680 camp and with an electrically dependant airplane I intend to stay there. I’ve been using these for many years and never had a failure. (I do have one that is nearly ten years old in my Z-turn that I suspect may not make it through another winter).
Weight may be the enemy but I heard a wise man make a statement that I took to heart:
“Don’t trade anything for reliablility! What ever you can get in exchange for reliability isn’t worth it.”
FWIW,
Dale
3.0 Corvair/Tailwheel
Re: Electrical Failure
Posted: Thu Jun 06, 2024 7:13 am
by GordonTurner
So sayeth the WW.
Re: Electrical Failure
Posted: Fri Jun 07, 2024 8:34 am
by Art Tiller
Yesterday I discovered “Battery Box Sizes”. Being a second owner and not very inclined to change out battery boxes I feel locked into Earth X Battery box size “E”. So, If I stay with EarthX then the most reasonable battery for me is either the ETX680 79MM. (I have no idea what the “79MM” means) or the ETX680 76MM. They are the same size as the ETX900 but have less cranking amps. I take it that is not a deal breaker for the AeroVee 2.0. Is there an AGM battery out there that shares the same dimensions as the EarthX ETX900? Probably not.
Re: Electrical Failure
Posted: Fri Jun 07, 2024 5:54 pm
by GordonTurner
Hi Art
I’m using a Shorai LiFePo….(?) battery intended for motorsports. Super light and small, wide selection of power, multiple case and terminal arrangements. I actually have two. See above for discount code.
Oh, and they come with a large amount of high quality dense foam of various thicknesses to get it fitted. Give me a shout if you are interested and have questions.
Gordon
Re: Electrical Failure
Posted: Tue Jul 02, 2024 12:06 pm
by DBrown
Bryan Cotton wrote:
Art Tiller wrote:So, if my battery box will accept it, I may buy an Odyssey PC680 AGM. $155 vs $699 for the EarthX.
The EarthX ETX680 is $379 at ACS.
https://www.aircraftspruce.com/catalog/ … key=402696I’m still an EarthX fan. Weight is the enemy.
Me too! I also have a small 1.3ah AGM backup battery. They are $15 and 1lb, I just replace it at every Condition inspection. No dig on Odyssey I just prefer the weight savings and the redundancy