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Left the master on!

OK, I left the master on, ran down the battery, was gone for three weeks. Discovered the error and had the 20 month old Concorde battery charged up to 14.2 volts.

Now, I want to make this clear, I placed the positive lead on the positive first, then the negative. Positive cable runs off the master relay switch and negative comes through firewall, grounded to the engine.

Wiring started to smoke, actually glowed, (the thin wire from master relay to the master switch, plus one more wire I believe leading to the bus.) Pulled the lead from the positive quickly. So somehow the negative ground was lost.

My system has been charging above 14 volts and higher previous to this.

Any ideas? Bad relay, regulator, or a short somewhere else in the system?

Thanks

Chris
RV6A
613LE
Las Cruces, NM
[email protected]
 
Could the battery have been charged backwards by accident? (reverse polarity) Making the negative positive and the positive negative.
 
No idea, but suggestion for prevention

I have my strobes on a separate switch and I leave them on. When I forget the master (easy to do without any spinning gyros to hear) the lights get my attention or at least someone's. When on, they are a legal alternative to a rotating beacon.

Sorry, but I can't be of any help on the charging problem.
 
Charge on Bench

Chris,

Take the battery out and charge on the bench. No use in burning out your wiring system for the sake of a $150 battery. Try installation and ops check once the battery has been ruled out.

BTW-My concorde 25XC is 10 years old and still pumping good voltage.

JB
 
Polarity

Could the battery have been charged backwards by accident? (reverse polarity) Making the negative positive and the positive negative.

Polarity doesn't have anything to do with the problem as described by Chris. With everything switched off, the only thing that will make hot wires and smoke is a short. The short could be wiring or in a component.


John Clark
RV8 N18U "Sunshine"
KSBA
 
Conchord Batteries can't take deep discharge

I have replaced 3 25XCs because I left the master on. When they are deep discharged this way for days thay are a throw away. Don't waste your time trying to bring them back if you have abused them in this manner - they are like a black box of unknown contents after this has happened. They can be charged normally if they are simply at a low state of charge but when you discharge them beyond this condition something physically changes inside the battery case and they are no longer a battery (it sounds like a dead short in this case). You can't even jump start the engine with them in the system. They work very well otherwise but long term deep discharge is something they can't handle like a traditional car lead acid battery.

Bob Axsom
 
I have replaced 3 25XCs because I left the master on. When they are deep discharged this way for days thay are a throw away. Don't waste your time trying to bring them back if you have abused them in this manner - they are like a black box of unknown contents after this has happened. They can be charged normally if they are simply at a low state of charge but when you discharge them beyond this condition something physically changes inside the battery case and they are no longer a battery (it sounds like a dead short in this case). You can't even jump start the engine with them in the system. They work very well otherwise but long term deep discharge is something they can't handle like a traditional car lead acid battery.

Bob Axsom


Bob, with all due repect this is not true, at least I have found the Concord batteries can be completely discharged (don't ask ;)) and brought back to service with no problem. The trick is a very low voltage charger or battery minder. It must be charged low & slow.

You cannot just throw a car battery charger on these batteries and hope for the best.

http://www.batteryminders.com/batterycharger/home.php
 
Last edited:
Wiring started to smoke, actually glowed, (the thin wire from master relay to the master switch, plus one more wire I believe leading to the bus.) Pulled the lead from the positive quickly. So somehow the negative ground was lost.

Did you connect the battery charger to the battery?

What voltage and amps was the charger? Was it a car battery charger? What amps? I think you just over charged the system.

http://www.batteryminders.com/batterycharger/home.php
 
I don't think you charged backward. It does not sound like a charging problem neither (14V is fine, your alternator put out more than that). Somehow you have a short in your circuit. The thin wire from mater switch to master relay should not be hot. During normal operation the mater relay coil consumes only one amp. The wire should not even be warm. I don't think you lost negative ground. Remove the battery (get a new one) trace all the hot wires (burnt) and you may find the short. Don't put in a new battery until you have the short isolated. Use a ohm meter to trace your circuit.
 
Polarity doesn't have anything to do with the problem as described by Chris. With everything switched off, the only thing that will make hot wires and smoke is a short. The short could be wiring or in a component.

I agree with RVaddict, if the battery was charged backwards (which it can be) the system diodes (alternator and spike diodes on the relays) can all act as shorts which would cause this. If you didn't have any problems before and all you did was replace the battery seems unlikely that a short would develop out of the blue :confused:
 
I have my strobes on a separate switch and I leave them on. When I forget the master (easy to do without any spinning gyros to hear) the lights get my attention or at least someone's. When on, they are a legal alternative to a rotating beacon.

Sorry, but I can't be of any help on the charging problem.

I know they (strobes) are a legal alternative to the beacon, BUT, they are really hard on everyone's eyes outside the airplane when you're on the ramp. As a courtesy, I always turn my off exiting the runway so everyone else is not blinded by them, especially at night. This was standard ops in the airlines. If you taxied on a ramp with your strobes on you could expect to get harassed. Same with a taxi light when you are pointing at another plane.
Just MHO.
 
Nothing is absolute

Thanks for the respect and I mean that. If you get the battery to comeback then it probably never really had a catastropic failure. Battery manufacturers are very secretive with good reason. In 1973 I was the resident representative for MDAC-E at Eagle-Picher in Joplin Missouri for the Airlock batteries used on the Skylab Project . We went to extreme lengths to match the cells (I can go into my detailed notes from that assignment if necessary). Every cell was made very carefully and serialized. The process was closely witnessed and every step was independently inspected to assure conformity. The cells were activated and sent through several charge/discharge cycles using a constant voltage technique so not to damage the cells as they neared full charge. Data was automatically taken for every cell and recorded on 9 track tape which I drove to St. Louis at night and delivered to Don Webb for processing. Based on the processing results the cells were assigned to battery sets with many more cells than required for each battery. The full set of charge/discharge cycles were rerun and the data processing cycle repeated several times. The cells were reassigned and physically moved to new battery cell groups to closely match the cells based on their actual performance. The cells had a very flat discharge curve until near the end of their capacity then the flat discharge would turn down very quickly (knee) and rapidly drop to zero. When the knee was recognized by a specific voltage level we shorted out the terminals on the specific cell to isolate it from the other cells in the battery unpackaged battery. These cells were designed with a feature to limit damaging gas production during discharge cycle but there is a limit and forcing flow through a cell that is depleated can be damaging.

The design compromises for performance and reliability in the Concorde batteries are unknown to me but on one ocassion I took my battery out on the ramp at Santa Ynes, CA and had the shop try to trickle charge it back to life and I ordered a new one from Aircraft Spruce while I drove the rental car up to Monterey. When I returned to fly back to Arkansas the dead battery was still dead in spite of the shop's effort to restore it. I took the battery that had been delivered by Aircraft Spruce, installed it and flew home. On each of the other ocassions I personally tried to charge at a 2 amp rate, it failed, I let it set for a day or so and tied again and it failed again. Whether the plates soften and decompose and particulates fall out of the grid and the buildup shorts or the dielectric is changed, I don't know but I have personally experienced the failure enough to know that If you leave your master on for several days there is a good chance that your Concord battery will be destroyed. I still use them and they give me good reliable service but I have increased my personal discipline to make sure I turn off the master switch.

Bob Axsom

Bob, with all due repect this is not true, at least I have found the Concord batteries can be completely discharged (don't ask ;)) and brought back to service with no problem. The trick is a very low voltage charger or battery minder. It must be charged low & slow.

You cannot just throw a car battery charger on these batteries and hope for the best.

http://www.batteryminders.com/batterycharger/home.php
 
Bob, with all due repect this is not true, at least I have found the Concord batteries can be completely discharged (don't ask ;)) and brought back to service with no problem. The trick is a very low voltage charger or battery minder. It must be charged low & slow.

You cannot just throw a car battery charger on these batteries and hope for the best.

http://www.batteryminders.com/batterycharger/home.php

Uuuhhh.....a Battery Minder will not charge a battery below about 10 volts or so. My Battery Minder wouldn't charge my Odyssey when I left my master switch on. I had to use a conventional charger. I looked in the Battery Minder manual and sure enough, it will not charge a discharged battery.
 
Uuuhhh.....a Battery Minder will not charge a battery below about 10 volts or so. My Battery Minder wouldn't charge my Odyssey when I left my master switch on. I had to use a conventional charger. I looked in the Battery Minder manual and sure enough, it will not charge a discharged battery.

Exactly my experience also, after 8 hours or so on lowest setting on my "regular" automotive charger, the Battery Minder topped off the charge, and went into blinking mode.

This was after a couple of weeks of Battery Minder alone.
 
Charging the wrong polarity is possible with an Odyssey so it is likely possible with yours also. This is with the correct leads on the correct posts. Having done the same trick with the master as you my Odyssey was dead after going back to the plane about 3 weeks later. The thing with the Odyssy is that it never reads like it is dead when putting a meter on it, but will come in around 11v or so. It is however totally dead. Using a charger that was purchased specifically to charge this type of battery the dumb thing just wouldn't charge from the way it was acting. After a call to the local battery store (where I bought the charger) that is a dealer for Odyssey they said that once one of these things go dead you have about a 50/50 chance of it trying to charge with the polarity wrong. The solution was to get it started the correct polarity and then switch over to the proper type of charger for these batteries. With a trip to somebodys house who has an old charger on a cart from the gas station days in the 50's we nailed that pesky battery with that for a few minutes to show it who the boss was going to be. A groan came the charger and the sound of real work being done filled the garage. Once the charge was inititialized and in the right polarity it was finished up on the bench with the charger I bought from the Odyssey store. I've been using this battery since.

Keep us posted on what you find. I always like to learn on the electrical problems.
 
Having joined the club of those who have left the master on last year. I got my Odyssey back to life by putting it on the charger with another battery in parallel for the first minute. My charger wouldn't start otherwise. I guess I was lucky as the battery has performed absolutely fine since

Peter
 
Battery discharged

No, no,.... I did not leave the master on, but still found the Odyssey discharged today! The master solenoid would not pull in.

I last charged it about 3 months ago, or so. I know that the Dynon "stay allive" and the ELT will use some electrons to keep things going, but I did not realise that they would discharge the battery that quick. So I put the charger on and found that after several hours, at about 6-8 Amps, the Dynon was showing still only 11,2 V, with the charger off. What I do not understand is why the battery is warming up, it never did that before, when I charged it for testing the instruments during installation. It is not "hot" hot, but just slightly warm, after several hours.

What best to do? I am not leaving it on, unattended, overnight, so I have switched everything off now and will try again tomorrow.

Regards, Tonny.
 
Tonny, I don't know if this will help much, but you might want to disconnect the "keep-alive" circuit on your Dynon unit. There was discussion on the Dynon website forum where people were having some issues with their Dynons not booting up properly (or something like that) after installing the firmware updates. Dynon's recommendation was to disconnect the keep-alive wire.

I did that and, when I noticed that I wasn't getting any fuel flow reading on my EMS, discovered that the yellow keep-alive wire is only one of THREE yellow wires in the EMS harness! Oops. I reconnected the yellow wire that I'd disconnected and cut the correct wire and miraculously had a fuel flow reading! Imagine that.

So, apparently Dynon doesn't think that you need a keep-alive wire anyway. One less thing to draw current.
 
Battery down from 11,2 to 10,4 V overnight....

Turned the master on this morning: the Dynon was showing 10,4 V. So the battery is definately not back up to where it should be. I understand from reading these posts that others have hit the battery with a fairly high charging current (+40 A), after it got discharged for some reason, either from the alternator or with a heavy charger. They, apparently, did not experience any problems in getting the battery back to life. I am wondering if that will do the trick?

I would hate to have to order a new battery when this one has not even seen any active duty, especially because by the time I get it to my doorstep it will be twice as expensive as what it cost in the USA (shipping, VAT, Import tax, Customs fees, etc.).

Thanks in advance for any advice.

Regards, Tonny.
 
buy locally

Tonny

I know these batteries are avaliable in the UK so I'm sure you should be able to buy locally in Belgium. One friend got one cheap off ebay.
Do a quick search on google

Cheers

Peter
 
I have replaced 3 25XCs because I left the master on. When they are deep discharged this way for days thay are a throw away. Don't waste your time trying to bring them back if you have abused them in this manner - they are like a black box of unknown contents after this has happened. They can be charged normally if they are simply at a low state of charge but when you discharge them beyond this condition something physically changes inside the battery case and they are no longer a battery (it sounds like a dead short in this case). You can't even jump start the engine with them in the system. They work very well otherwise but long term deep discharge is something they can't handle like a traditional car lead acid battery.

Bob Axsom

I've had only one RG-25XC for over 10 years, and have left the master on 4-5 times over 1100+ hours. They will come back to full capacity (or close to it) after a few charge cycles.
 
Success !

Yesterday I took a heavy 70 A charger back home, from work. Took the battery out of the plane and hooked it up. I started it up in the lower range, while monitoring the Voltage on a digital meter. After a couple of minutes I was able to go to the ?High? setting without the voltage going over 15 V. Left it on that for about 45 min., while it was charging at approx. 22 A. After that I switched it back to the ?low? setting and left it charging for a couple of hours. When I turned everything off, the battery stabilized at 12,9 V. This morning I checked it again and it was still at 12,9 V. So I?m confident that the battery is fine.

From now on, I will leave it disconnected as long as I am still building and will top it up every now and than, to keep it in good condition.

Regards, Tonny.
 
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