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PC680 batteries

My buddy replaced his 680 in his RV-12 in Oct of 2018. It was dead by May 2019. Probably 34 hrs of flying time in that period. Dead cell. Air Spruce replaced it under warranty. New battery was dead by early Sept this year. Dead cell ,voltage falling of 0.1 to 0.2v per day. Lasted 4 months. Air Spruce replaced it again under warranty. Had to pay return shipping.

RV-12, and it charges normally, at 14.3V after start up, at about 8 amps and quickly falls, if on a Rotax 912, the rpms for warm up are kept at 24-2500 rpms. At 2000 rpm, the battery is -2 amps /hr.

I saw another post from someone also mentioning short battery life on their 680 recently.
 
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I?m curious to know if anyone looks for parasite drain that would lead to long term undervolt on the battery. Is the amperage draw truly zero when the master is off?
 
My first Odyssey lasted 4 years, the second lasted 3, and today my third one went dead only after 10 month of usage. I fly my -7 regularly and never used any battery chargers. As mentioned by others, quality has been going downward in the past few years, even though some people seem to be happy with theirs.
I?m tempted to just go to Walmart and buy a cheap tractor battery, cannot be any worse, can it ?
 
I?m curious to know if anyone looks for parasite drain that would lead to long term undervolt on the battery. Is the amperage draw truly zero when the master is off?

It is if that's all you have connected to the + terminal.......
 
Me too - no not the hash tag

10 year old 7, 1500 hours - I fly a lot.
First one lasted three years and totally drained twice but came back to life both times.

Second one lasted four years and totally drained once but also came back to life.

Third lasted over two years.

Fourth installed December 2018 - dead in September 2019 - never drained.
Fifth one installed September 2019 - Dead at Petit Jean October 2019 (this month). Again, never drained.

Sorry, Larry, there is NO parasitic drag. None!
I have both PC680s sitting on a bench and am testing them with a NOCO g7200 and load tester. We'll see, but I suspect something is being built differently at the factory.


Just installed an Apex.
 
My buddy is once again replacing his PC625 Odyssey in his Cozy MKIV with less than a year of service on it. We talked about it yesterday and he is going to give the Apex battery a try for a replacement.
 
wheres the best place to order a PC680 battery? I see they are on spruce +$18 shipping & batterymart with free shipping
 
I have a great 140 hour like new PC680 and a new in box battery minder. Shipping might be pricey but they are for sale.
 
Possible shorted rectifier diode in the alternator

My buddy replaced his 680 in his RV-12 in Oct of 2018. It was dead by May 2019. Probably 34 hrs of flying time in that period. Dead cell. Air Spruce replaced it under warranty. New battery was dead by early Sept this year. Dead cell ,voltage falling of 0.1 to 0.2v per day. Lasted 4 months. Air Spruce replaced it again under warranty. Had to pay return shipping.

RV-12, and it charges normally, at 14.3V after start up, at about 8 amps and quickly falls, if on a Rotax 912, the rpms for warm up are kept at 24-2500 rpms. At 2000 rpm, the battery is -2 amps /hr.

I saw another post from someone also mentioning short battery life on their 680 recently.

The symptoms you are reporting and the very short life spans of these batteries coincides exactly like the symptoms of an alternator that has one or more shorted rectifier diodes. 95% of the time when a rectifier diode fails it fails open circuit. You then generally lose one sixth of your alternators output for every diode that fails. So it's fairly easy to determine that you've got a bad alternator. However when a rectifier diode fails shorted, the alternator will still pass charging testing. However what is happening is that that diode is allowing AC current to pass to the battery. Alternating current will destroy a battery in very short order. Unless the charging system is tested with a high quality tester that has the capability to find this issue, the test won't find anything wrong.

Charlie
 
The symptoms you are reporting and the very short life spans of these batteries coincides exactly like the symptoms of an alternator that has one or more shorted rectifier diodes. 95% of the time when a rectifier diode fails it fails open circuit. You then generally lose one sixth of your alternators output for every diode that fails. So it's fairly easy to determine that you've got a bad alternator. However when a rectifier diode fails shorted, the alternator will still pass charging testing. However what is happening is that that diode is allowing AC current to pass to the battery. Alternating current will destroy a battery in very short order. Unless the charging system is tested with a high quality tester that has the capability to find this issue, the test won't find anything wrong.

Charlie

Would putting a 'noise filter' and additional diode on the alternator output help?

High Capacity diode
Large Capacitor
Maybe even an inductor

?
 
To test for a shorted diode (rare) just put you meter on AC with the engine running, should be '0'.
 
To see the AC ripple voltage output of an alternator you need to connect as close to the alternator as possible.

Connect - to alternator case, + to alternator output.

The battery acts like a large capacitor. If you test at battery, you may not see the AC ripple.
 
Most inexpensive multimeters just use an internal diode for ?ac?. Procedure: connect multimeter to ?hot? wire, near alternator. Connect other multimeter lead to ground. Set multimeter to ac. Turn on electrical power but leave engine off. If voltmeter reads zero, good. If it does not, reverse the leads. It should then read zero. Start the engine, alternator on, read any ac voltage present.
 
For the past 4-6 weeks, I've been noticing some suspicious behavior during the first start of the day. The prop would turn just a bit and then stop turning for a half second or so (with a slight buzzing sound during the no prop rotation) and then begin turning again. Wasn't sure if it was the PC680 battery or what?

Sunday, the battery didn't have sufficient power to turn the prop. It was OK to turn on the PFD, and the fuel pump, but it was only showing 11.7 volts. Previous flight was just four days prior, where the prop was slow to turn initially, but no issue other than that.

Took the battery in to get tested and they said that it had 2% charge only, but that it tested OK once charged up. I bought a new PC680 anyhow, even though this one was only 14 months old. I just didn't trust it, after the slow prop turns I've been experiencing.

Installed the new battery this afternoon, and took the airplane for a flight. The prop turned much faster during the start, and no hesitation at all...

14 months isn't exactly impressive battery life...
 
Took the battery in to get tested and they said that it had 2% charge only, but that it tested OK once charged up.

Seems to be a bit of a red flag to make sure your charging system is doing its job.
 
Seems to be a bit of a red flag to make sure your charging system is doing its job.

With the alternator on, voltage is 14.3 and alternator is putting out 13 amps. After engine start, there is an initial 18-19 amps shown, and then after a short bit, amperage goes down to 12-13. The alternator seems to be charging the battery OK.
 
At what voltages do you normally see your PC680 before engine start with some consumers turned on? Let‘s say at around a 4Amp load?
 
If the voltage is above 14, then the charging system is working fine.
If you have any more problems starting the engine, the next things to check are
wire terminations, battery contactor, starter contactor, and starter motor.
 
Another plan that worked for me

I always thought that the internal regulated alternators I used did not smack the PC680 with enough volts - at least the voltage wasn’t quite what the battery needed for a full charge (14.7V for charging per the Odyssey charts). I changed over to the B&C setup, then looked at what the Odyssey folks said should be used during charging: 14.7V. I set the B&C controller to that number and the battery started acting very different from previous normal voltages (13.7 - 14.0) to 14.5 - 14.7V in flight. Resting voltage changed a little - maybe to 12.4 or so - but the battery seemed to have more oomph when asked to start the engine (TCM IO550-N).

In-flight voltage settled around 14.5 - 14.7, with the alternator showing about 25A on the takeoff roll and around 8-10A in flight (with some time to charge up).

My pile of PC680s is still in the shop - used for weights etc. I expect this particular battery to keep going as it seems ‘happier’ with the higher voltage from the regulator.

So my fix for this problem was to jack up the charging voltage to 14.7, per B&C and Odyssey instructions. If possible, you should jack up the charging voltage for the PC680 in your plane; you might need to change to B&C parts to do this?

The next build has the same single alternator/controller setup, but pushing two EarthX 680-sized replacements in that ship. I hope that does not open up another can of worms!! The new ship is totally electronic (fuel, ignition, G3X etc) so a failure would not be a healthy situation...
 
I always thought that the internal regulated alternators I used did not smack the PC680 with enough volts - at least the voltage wasn’t quite what the battery needed for a full charge (14.7V for charging per the Odyssey charts). I changed over to the B&C setup, then looked at what the Odyssey folks said should be used during charging: 14.7V. I set the B&C controller to that number and the battery started acting very different from previous normal voltages (13.7 - 14.0) to 14.5 - 14.7V in flight. Resting voltage changed a little - maybe to 12.4 or so - but the battery seemed to have more oomph when asked to start the engine (TCM IO550-N).

In-flight voltage settled around 14.5 - 14.7, with the alternator showing about 25A on the takeoff roll and around 8-10A in flight (with some time to charge up).

My pile of PC680s is still in the shop - used for weights etc. I expect this particular battery to keep going as it seems ‘happier’ with the higher voltage from the regulator.

So my fix for this problem was to jack up the charging voltage to 14.7, per B&C and Odyssey instructions. If possible, you should jack up the charging voltage for the PC680 in your plane; you might need to change to B&C parts to do this?

The next build has the same single alternator/controller setup, but pushing two EarthX 680-sized replacements in that ship. I hope that does not open up another can of worms!! The new ship is totally electronic (fuel, ignition, G3X etc) so a failure would not be a healthy situation...

Recommended charging voltage is different than a float voltage. Yes, when charging a battery you should run it all the way up to the charging voltage. However, once it is charged, it should not be floated there; It is too high and will take life off the battery. If you dig into the specs more, you will find another recommendation for floating voltage or maintenance voltage. It is usually listed in volts/cell and it is usually in the neighborhood of 13.8-14.2 for 12V SLA batteries.

It is true that a battery in an auto/aircraft configuration never reaches a full charge due to not hitting the charge voltage. However, it also doesn't burn out prematurely by constantly running at the charging voltage. It is a trade off. Charging voltages should only be used by charging systems that are capable of turning it off or reducing voltage once charged.

I question your statement that B&C recommends 14.7 volts. They should know better than that and I wonder if you mis-understood something. Odyssey definitely does NOT recommend a constant float voltage rate of 14.7; Only a final charge rate of 14.7. They are very different.
 
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Recommended charging voltage is different than a float voltage. Yes, when charging a battery you should run it all the way up to the charging voltage. However, once it is charged, it should not be floated there; It is too high and will take life off the battery. If you dig into the specs more, you will find another recommendation for floating voltage or maintenance voltage. It is usually listed in volts/cell and it is usually in the neighborhood of 13.8-14.2 for 12V SLA batteries.

It is true that a battery in an auto/aircraft configuration never reaches a full charge due to not hitting the charge voltage. However, it also doesn't burn out prematurely by constantly running at the charging voltage. It is a trade off. Charging voltages should only be used by charging systems that are capable of turning it off or reducing voltage once charged.
+1
Running above 14.2vdc in steady state is not a good for battery longevity.

When doing hangar flying (running the panel) I set my 30amp regulated power supply to 13.8vdc to start, then ease it up to 14.2 after the batteries take on the initial charge, just like your alternator will do.

I never use a battery charger for this.

Carl
 
OK - so who makes the right parts?

I have not seen another piece of equipment that will punch the PC680 with 14.7V as it requires. B&C said turn it up, and the Odyssey chart said the same thing. Please tell me what I should replace (or add to) my system with so that the dang PC680 stays charged besides the charger in the hangar?

Flew around for about 20 min today - landed with idling voltage around 13.2 or so at shutdown; that changes to about 12.3 overnight. In the air, voltage was around 14.3 with amps at 10-12 or so.

I do not think the current system will cook (overcharge) the PC680, but it will be charged within limits if I fly long enough.

So: tell me what I should do instead of what I am doing? Note I have a pile of 680s in the shop, and this one seems to be working closer to what it is supposed to do: staying alive.

See: https://www.odysseybatteries.com/docs/odyssey_battery_charger_manual.pdf

Look to page 9 (the charging rate and voltage) and then tell me what to do besides set the regulator at 14.7V as the Odyssey charger does. It says the battery is full when it has 14.7V...which at that point my ship’s amp meter would show 0 amps (remember I set the regulator at 14.7)...or am I wrong about amps vs volts?

Then again, I could be reading the Odyssey manual wrong...
 
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I've been running my B&C reg at 14.6 - 14.7v for the last 15 years with the PC680, never had any issues with my batteries, however I do replace the battery every 3 yrs as preventive mntc.
 
responses in line

I have not seen another piece of equipment that will punch the PC680 with 14.7V as it requires. B&C said turn it up, and the Odyssey chart said the same thing. Please tell me what I should replace (or add to) my system with so that the dang PC680 stays charged besides the charger in the hangar?

First, stop using a charger in the hanger. History on this site has shown that that MANY SLA battery failures are related to long-term charger use. SLA's don't need long term charging and the wrong type of charger will insure a short life.

Flew around for about 20 min today - landed with idling voltage around 13.2 or so at shutdown; that changes to about 12.3 overnight.

A good SLA battery will read 12.8 - 13.0 approximately 12 hours after charging or flying. At 12.3, your battery is toast - 45% capacity.

I do not think the current system will cook (overcharge) the PC680, but it will be charged within limits if I fly long enough.


Not sure what you base that opinion on, but this is america and you are welcome to have one and express it.


So: tell me what I should do instead of what I am doing? Note I have a pile of 680s in the shop, and this one seems to be working closer to what it is supposed to do: staying alive.

Stop putting your battery on a charger when not flying, unless it is an odyssey branded charger. An SLA battery will hold about 85% of it's charge over a 6 month period. It has a very low self-discharge rate compared to the flooded lead acid battery in your car.

See: https://www.odysseybatteries.com/docs/odyssey_battery_charger_manual.pdf

Look to page 9 (the charging rate and voltage) and then tell me what to do besides set the regulator at 14.7V as the Odyssey charger does. It says the battery is full when it has 14.7V...which at that point my ship’s amp meter would show 0 amps (remember I set the regulator at 14.7)...or am I wrong about amps vs volts?


The odyssey charger is a charger and it shuts off once the battery is charged. It then turns itself back to charging mode if the voltage drops. This prevents it from cooking the battery. This does not mean that you should constantly float your battery at that voltage. Auto batteries are also charged around 14.8 volts. Find me an auto manfucturer that uses a regulator with a 14.7 voltage; They all use about 14.3-14.4. If you do more research, you will begin to understand the difference between charging voltage, equalizing voltage and float voltage.

Back in the day, I sold very large phone systems. Customer called one day furious that there battery bank on the UPS only held for 30 minutes during a power outage only a few months after installation. When we investigated, we found that the customer had left the switch on equalize (.4 volts higher than the float) and he had cooked the batteries.


Then again, I could be reading the Odyssey manual wrong...
 
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Saying that putting a charger on a PC-680 is bad and will ruin the battery is not correct. Use the correct charger and the battery will last a long time.

Two things kill these batteries:

1. Overcharging at too high a voltage or for too long using a charger that doesn't adjust the charge according to the battery's condition

2. Not charging the battery enough and letting the voltage fall too low for a period of time.

The best thing to do is to fly at least once a week with an alternator that puts out the correct voltage range. If that is not possible, then the proper charger will extend the battery's life. Over the years as I flew less, I had a problem with the batteries not lasting more than a year or two. I bought Yuasa battery maintainer/chargers and leave on the batteries any time it's sitting. This has improved my battery life to 4 years so far and the battery spins the prop very well.

There are cases where people have used the wrong charger and ruined the battery - all chargers are not the same. I just want to clarify that using a charger on the battery is not going to destroy it if you use the correct one.
Same batteries still working after 9 years.....
 
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