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-   -   What killed this PC680? (https://vansairforce.net/community/showthread.php?t=99810)

APACHE 56 06-20-2013 12:26 PM

Bottom line is that it is the same battery it always was, they just reduced its rating after they actually tested it. The prior rating was an estimate.[/quote]

Thanks Brian.

blueflyer 06-20-2013 01:25 PM

Quote:

Originally Posted by APACHE 56 (Post 781072)
....... I told him that I may have had the charger ring terminals positioned between the #2 wire ring terminal and the batt. That, he replied, is not good. .......
Don

Don
Do you recall why he said this is a bad idea? It would seem that Odyssey makes these quick connectors to be used in just that manner. I will admit I have never read through the Odyssey battery literature to see what they say regarding this issue and there is no doubt Bill Bainbridge is much more knowledgeable than I.

APACHE 56 06-20-2013 04:02 PM

Good connections...
 
Quote:

Originally Posted by blueflyer (Post 781307)
Don
Do you recall why he said this is a bad idea? It would seem that Odyssey makes these quick connectors to be used in just that manner. I will admit I have never read through the Odyssey battery literature to see what they say regarding this issue and there is no doubt Bill Bainbridge is much more knowledgeable than I.

He was responding to my comment that I may have placed the charger pigtail below the cable ring terminal. His concern was insuring a good contact. I will continue to keep my charger cable permanently installed on the battery.

Walt 06-20-2013 04:51 PM

Quote:

Originally Posted by Bill.Peyton (Post 781119)
Walt,
I have to disagree with you.
The field of any alternator is what is used to regulate the output. The field line on the PP alternator is used for two things, one is to energize the field and the second is to sense the "output" voltage. If the voltage drop across the field wire running from the power source to the alternator is such that at the alternator end of the wire, it is less than the actual bus voltage, then the internal regulator will continue to increase the field current until the output of the alternator drives the voltage at the field terminal to whatever the regulator has been programmed. In the case of the PP alternator, it is 14.2 volts. So until 14.2 volts appears on the field terminal, the internal alternator regulator will continue to drive the field until the voltage is 14.2v.
With an externally regulated alternator, the sense line is different than the field line in that the sense line is connected to the bus and the field current is varied through the regulator. This is not to say that you can't trick an externally regulated alternator that does not have an adjustable output, to output a higher voltage by simply dropping the voltage to the sense line.

Bill,
Thanks for bringing this up and I stand corrected. I contacted PP and they confirmed they did indeed tap off the field terminal for the internal regulator sense functlion. However the problem I see with regulating the alternator by increasing the resistance of the field wire (same as installing a resistor in the field supply) is that as the voltage drops on the bus and the field draws more current there will be an additional voltage drop at the field, so the alterator will overcompensate. So the higher the field current the higher the bus voltage will be. At least thats my theory, I would be very interested to know how it actually works though in the real world.

Russ McCutcheon 07-05-2013 08:04 PM

It died on the 4th
 
I installed a new Concorde battery and flew with a good volt meter, I'm only charging at 13.90 volts. could this be cutting the battery life short? I am/was using the Odyssey charger between flights.

Bill.Peyton 07-06-2013 07:05 AM

Russ,
The normal charging voltage for a lead acid battery is 13.8 -14.2 volts. This is where most regulators are set. If it is not a sealed battery and you charge it with too high of a voltage, you will overheat it during the charge cycle and boil the water out which will require you to frequently check the level of the battery. I don't believe that charging it with the 13.9 volts you are seeing, will damage or shorten the life of your battery. What I question is the need to continually trickle charge your battery. Rarely do I see aircraft trickle charged during inactivity. The only instance you may need to do this is if the aircraft is rarely flown. I would contact Concorde and see what they recommend for both the charging voltage and the maintenance voltage.

Russ McCutcheon 07-06-2013 08:33 AM

Quote:

Originally Posted by Russ McCutcheon (Post 777568)
One more data point. I decided to replace my heavy Concord 25 battery with the PC-680, I kept it plugged into a battery Tender when on the ground, after 9 months it was done, I replaced it with a new PC-680 and never plugged it on to a charger, after 9 months it was done, I though I?ll try it one more time, I bought a new PC-680 and a new Odyssey 6A charger and kept it plugged into the Odyssey charger, after about 11 months it was starting to seem weak, after reading this thread I ran it down with the landing lights to 10 volts and recharged, I did this twice and it cranks like new again. I bet I have two good PC-680s sitting on the bench that just need rejuvenating.

Just to refresh it was the most recent Odyssey battery that died on the 4th; it lasted about a year using the Odyssey charger, a little better than the first two. If 13.9v is ok then I don?t know why I?m having problems using the Odyssey batteries, for now I have given up and bought and installed a new Concorde RG-25XC like the one that lasted the 7 previous years before trying the Odyssey.

Sam Buchanan 07-06-2013 11:55 AM

Quote:

Originally Posted by Russ McCutcheon (Post 785562)
Just to refresh it was the most recent Odyssey battery that died on the 4th; it lasted about a year using the Odyssey charger, a little better than the first two. If 13.9v is ok then I don’t know why I’m having problems using the Odyssey batteries, for now I have given up and bought and installed a new Concorde RG-25XC like the one that lasted the 7 previous years before trying the Odyssey.

Russ, 13.9v is low for an Odyssey, if I recall correctly they should be charged at about 14.5v. I doubt a PC680 will ever achieve full charge at 13.9v. But I don't know if undercharging will shorten the lifespan.

If you have an emergency bus with a diode in the circuit, voltage will vary depending on where you take the reading. The diode will absorb about 0.5v and make your system appear to be undercharging if you read voltage downstream from the diode. But you need ~14.5v going to the battery.

Bill.Peyton 07-06-2013 02:28 PM

What Sam said. Odyssey recommends charging there batteries at at least 14.5V.

Russ McCutcheon 07-06-2013 08:37 PM

Quote:

Originally Posted by Sam Buchanan (Post 785609)
Russ, 13.9v is low for an Odyssey, if I recall correctly they should be charged at about 14.5v. I doubt a PC680 will ever achieve full charge at 13.9v. But I don't know if undercharging will shorten the lifespan.

If you have an emergency bus with a diode in the circuit, voltage will vary depending on where you take the reading. The diode will absorb about 0.5v and make your system appear to be undercharging if you read voltage downstream from the diode. But you need ~14.5v going to the battery.

I was getting the 13.9 reading directly off the battery. I wonder how it would affect it since it only is in this under charged state for an hour or two each week, the rest of the time it was on their charger fully charged.

So I just put this battery in http://www.concordebattery.com/flyer.php?id=36
what?s the recommended charging voltage for it? I believe I can adjust my B&C regulator, I?ll be calling Bill (B&C) Monday.


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