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Odyssey battery Rejuvenation

Mike S

Senior Curmudgeon
The following "borrowed" from Brian Chesteen. Rejuvenation instructions for a sulfated battery.

I have been in contact with the folks at the Odyssey battery headquarters. They are very helpful folks. They have instructed batterymart.com to give me credit under warranty for the 6 month old battery.

They tell me that the primary reason for an Odyssey battery to have the symptoms that my 6 month old and 3 year old battery had was sulfation.

They also gave me a special procedure to follow to desulfate the battery if it can be saved. The prodedure is to discharge the battery at the 5hr rate maximum down to ~10v under load. For the PC680, that is 3 amps max. And then to use the 6 amp Ultimizer to recharge the battery till it goes into trickle mode and to do this as many times as needed as long as the discharge time keeps taking longer than the last cycle.

I found my oldest battery (never threw it out) with a date code of July 09. It was replaced back in the fall of last year due to the same symptoms. I wanted to see if the special procedure could bring this thing back to life. So far I have completed 3 cycles on the battery. The first lasted about 5 minutes, the second almost 2 hours, and the third was well over 4 hours and tonight I plan to try another one. The bottom line is that this procedure seems to be working to revive this battery.

The only thing the support from Odyssey cannot explain is why these batteries are getting sulfated so quickly or at all in this application and with the continuous use of the Ultimizer charger.

I am a bunch more educated about these batteries now and I think the new one is going to last a long time even if I have to perform regular desulfating procedures on it. I still do not plan to keep it on the Ultimizer continuously.


This now reflects the latest info from Brian, as of 1-26-21. The original post stated the battery was to be drawn down to 10v OPEN circuit voltage-----that has been updated to reflect the current info from Odyssey to read 10v LOADED circuit voltage.
 
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Odyssey did come back with an answer on what they thought the reason was that I killed these 2 batteries so quickly.

They claimed the problem was sulfation of the battery by being stored (even shortly since I fly almost once a week) at something less than full charge.

Apparently the Odyssey is can sulfate quicker than other types of batteries due to how it is made and how thin the plates are.

Symptoms of this failure mode are apparent full charge voltage but no capacity to do any real work....

They claimed that the issue may have been my constant use of the Odyssey Ultimizer Charger (almost any smart charger will have the same issue).

They said that the Odyssey battery needs to spend a certain amount of time in the absorption phase of the charge. The length of time spent here is dependant on how discharged the battery is. The voltage needs to be at least 14 or more volts during this time. The manuals say 14.7v.

Here is the theory...When using the Odyssey Ultimizer, the charger looks at the voltage of the battery when you turn it on. If the voltage is high enough to start with or rises quickly, the charger will very quickly kick into trickle mode and won't spend much time in the absorption phase of the charge. Odyssey says this can cause what I experienced due to the fact that the battery is not getting fully charged.

Their recommendation was to always discharge the battery enough that the Ultimizer charger will not think the battery is fully charged quickly after hooking it up and turning it on. This will allow the normal absorption charge cycle to complete properly.

So to recap here are their recommendations:

  • Never store your Odyssey battery (even for just a week, the effect is cumulative) on less than a full charge
  • Never put the battery on the Ultimizer charger unless it is discharged enough to allow the absorption phase to complete properly. If it quickly switches to trickle after you used the battery, most likely it will not be fully recharged.


I think my habits of doing a ton of avionics tweaking/hangar flying on the ground and constantly just trusting the Ultimizer charger to take care of the battery was what killed my two batteries prematurely. I remember it switching to trickle quickly most times.

Folks that fly often and always fly long enough to allow their alternator to recharge their battery fully after starting may not experience this issue often if ever as long as their main bus volts are up where they need to be.

Folks that have low main bus volts while the alternator is running may have issues prematurely. The manual wants 14.7v...I doubt many of us have that high of main bus voltage while running. Mine runs between 14.2-14.4 and I have an internally regulated PlanePower alternator.

Since learning this info, I always either fly long enough to allow a full recharge or if I use the Ultimizer charger, I always run some load until the surface charge of the battery is burned off. This allows the Ultimizer to spend all the time it needs in the absorption phase. The difference in the time it takes to switch to trickle is significant using this method. So far so good with the replacement battery!
 
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This sounds familiar to what is going on with my battery. I have a two year old Odyssey 680 that is having a hard time swinging the prop. I have deep cycled the battery 5 times and after placing the battery on an analyzer the performance increase went from 30% to 35%. The batteries history is mostly short flights followed by connecting a battery minder. I have ordered a new 680 and was wondering if it would be best to charge the new battery before use or are these batteries fully charged?

Save the batteries fly more!



Russ Keith
RV-9A Flying N1909K
 
Timely information because I am having the same issue with my avionics backup battery which I am only getting a year of use from before having to replace.
 
I bought rv8 one year ago that has the 680 and the battery will not spin prop on first try. It takes a release of starter and a second try to get it to spin. This is when the temps are around 40 degrees. Should a healthy battery spin the prop first try at these temps?
 
How are you doing the discharge procedure?

The line you are quoting was from Brian--------sorry for the confusion, I did a color change to the OP to make it easier to figure out. Brian's words now in red.

Long winded way of saying----------ask Brian;)
 
How are you doing the discharge procedure?

I used an old headlamp off of something. It drew about the correct amount of current. You don't want a high discharge rate or the procedure will not be as effective. The efficiency of this procedure is tied to the discharge rate because the efficiency of the Odyssey goes down with increased rates of discharge.

At least that is what the folks at Odyssey told me....
 
3rd PC680 in 16 months

Add me to the data.

#1 purchased from Vans 9/18/12
Airworthy certificate July 3, 2013. The battery started failing on repeated starts during prop balancing.
#2 purchased from Aircraft Spruce 9/13/13
Stranded at KCHD. Fully charged, load test drops to 8 volts in 3 seconds.
#3 purchased from Batteries Plus on 1/22/14.

I have regularly used a Schumacher smart charger on #1 and #2. #3 has not been on a charger and based on this thread it wont. I will fly regularly and see what happens.
 
Rather that manually desulfating the battery might a product like BatteryMinder work? I would be interested in what Odyssey has to say about that product. We kept one on our Concord battery in our Cirrus for several years and enjoyed excellent service life. http://batteryminders.com/
 
I have had my PC680 for almost 1.5 years now and have kept it on a Battery Tender. Several of the others here at KJZP with the PC680 also have Battery Tenders on their batteries. The only problem was this one occurance.

When I finally got the Transponder certified and the ADS-B check out at an avionics shop after about an hour and 15 minutes with all the avionics running the battery would not crank the plane. They had a charger and we hooked it up to the leads that I use for the battery tender...

Still no luck...

Finally with just the aircraft sitting there we got a blade to finally turn over and it started... The amp meter showed a 30 amp charge when we turned on the alternator switch Normally this is about 4 amps after cranking.

Got back to Jasper hooked up the battery tender and it showed that the battery was dead or not connected properly.:( ( I assumed we killed the battery )
Went down the street bought another battery hooked it up and the battery tender again...( it too showed the battery was hooked up wrong or dead).:confused:

I am stumped... I hook up a 10 amp car charger to the battery tender leads that are connected to the battery... still Nothing... I am really stumped...:confused::confused:

then I brushed against an inline fuse holder..... that is installed on the Battery Tender wires to the battery..... opened up the cover and the fuse was blown.... It was a 5 amp fuse...:D

The avionics shop 25 amp rapid charger connected to the battery tender wires to my battery fried the fuse...

Replaced the fuse..... everything charged up....:)

Live and learn...

Jack
 
When I finally got the Transponder certified and the ADS-B check out at an avionics shop after about an hour and 15 minutes with all the avionics running the battery would not crank the plane. They had a charger and we hooked it up to the leads that I use for the battery tender...

Just FYI, I would never, ever, run a customers airplane on the battery for an hour or more (about 10 minutes is my limit without putting it on a GPU).. the results were quite predictable.
 
I used an old headlamp off of something. It drew about the correct amount of current. You don't want a high discharge rate or the procedure will not be as effective. The efficiency of this procedure is tied to the discharge rate because the efficiency of the Odyssey goes down with increased rates of discharge.

At least that is what the folks at Odyssey told me....

I need to try this. Any idea what in the airplane would put this 3 amp draw on it? Maybe just the master or position lights or....?
Thanks!
 
Any idea what in the airplane would put this 3 amp draw on it? Maybe just the master or position lights or....?

I get a gut reaction here about doing the battery cycling while it is in the plane.

I would remove the battery, and do the rejuvenation cycle on the bench.

As to the load, 3A load on a 12V system is 36 watts-------easier to find something labeled in watts than amps. A headlight was mentioned earlier, probably a good place to look for something putting out 36W.

Good luck, let us know how it works for you.

However you end up doing this, please be safe.
 
I get a gut reaction here about doing the battery cycling while it is in the plane.

I would remove the battery, and do the rejuvenation cycle on the bench.

As to the load, 3A load on a 12V system is 36 watts-------easier to find something labeled in watts than amps. A headlight was mentioned earlier, probably a good place to look for something putting out 36W.

Good luck, let us know how it works for you.

However you end up doing this, please be safe.

New battery just landed on the porch. Will switch them out then try the rejuvenation on the bench as you suggest. Did you do this to the one I gave you a couple years ago? Sounds like what it need. Hope it's not the starter that's bad. I asked the starter and alternator manufacturers about overhaul and they both said their products should go 2000 hours. They have 800 on them. This battery did sit several months while I overhauled the engine. I did that math too but don't have any 30 something watt gadgets. May just go to the auto parts store and look for bulbs.
Thanks!
 
I bought my first battery in 2007, changed it 2012 just because I figured it didn't owe me anything. Then I sold it for $40 :D it never had a charger used on it but once or twice briefly. Second battery working well and never seen a charger of any type.
 
Did you do this to the one I gave you a couple years ago?


No, I did not try the rejuvenation on it-------did not know of it at the time.

As I recall, I just put it on the battery minder for a week or so in the de-sulphide mode. After that I used it while doing bench testing of the panel while I was building it.

As this is the backup/e buss battery, it is not used to start the plane, so all has been fine with it. Finally changed it out last annual, just because------it is now in my motorcycle.

167981_400x400.jpg
 
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Rather that manually desulfating the battery might a product like BatteryMinder work? I would be interested in what Odyssey has to say about that product. We kept one on our Concord battery in our Cirrus for several years and enjoyed excellent service life. http://batteryminders.com/

In the 15 years I have been using the BatteryMinders I have never had to replace an Odyssey.

Also before shut down I turnoff most amp drawing avionics and allow the battery to charge with the alternator until the volts are at least 14.2. This is especially important at night taxiing with lights on. Goes back to my 57 Chevy with a generator a guess. ;)
 
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Here is the "rest of the story" directly from EnerSys:

The manual reconditioning cycle requires slowly discharging the battery to a loaded voltage of 10.5V then charging the battery at 6A or higher not to exceed 15.0V while charging or the battery can become overheated due to overcharging. The discharge, charge procedure can be performed multiple times. With each successive discharge, it should take longer to discharge the battery from a “full” state of charge to 10.5V using the same load. This would indicate recovery of capacity with longer run times. The best discharge rate for this sized battery is about 3A. A headlamp on a motorcycle works pretty good too…

If at any time during the charging process the battery begins to vent, hiss, or gets so hot you cannot hold your hand on the battery, then discontinue charging and allow for the battery to cool completely (1-2 days) before attempting to charge the battery again. Warm is OK. Hot is bad. If the battery is overheating at a charging voltage less than 15.0V, then there may be an internal issue that may be permanent and irreversible. If this situation occurs twice then the battery should be replaced. If the charger keeps exceeding 15.0V and causing an overheat situation, discontinue using the charger.

ODYSSEY Battery basics…

Most conventional batteries are considered fully charged at 12.6-12.7V. The ODYSSEY TPPL AGM battery is not considered fully charged unless it has a resting voltage of at least 12.84V. The usable energy of the ODYSSEY battery is from 11.2V (0% state of charge) OCV to 12.84V OCV (Open Circuit Voltage should be checked 8 – 24 hours post charge with no loads). When the battery goes below 10.0V OCV it is over discharged and is getting into the chemical part of the battery and can cause permanent damage. At less than 10.0V the ODYSSEY limited warranty deems the battery over-discharged due to abuse or neglect (usually unintentional). The ODYSSEY charger/maintainer or any approved maintainer can maintain the ODYSSEY battery indefinitely in or out of the application provided it has enough charging current to counteract the parasitic loads of the application. If the battery becomes over-discharged (below 11.0V OCV) then the sooner the battery can be fully charged the better. If the battery remains connected to the application during storage or extended periods of non-use, to prevent over-discharge and maintain the battery at a full state of charge, an ODYSSEY program approved maintainer would be required and/or disconnecting the battery prevent over discharge. There is a link to a list of ODYSSEY approved 12V chargers located on the ODYSSEY website Literature page for your reference.

The list of approved 12V chargers is provided due to the many chargers that are programmed for the vast majority of batteries on the market that prefer low amp charging and lower float voltages that do not fully charge or maintain the ODYSSEY battery properly. The minimum recommended charging current for an ODYSSEY battery is 40% of the 10 hour amp hour rating of the battery for cyclic or deep discharge applications (about 6A for a single 16Ah rated PC680 for example), a constant float voltage of 13.5-13.8V and no constant voltages exceeding 15.0V in any kind of de-sulfation/reconditioning/equalize mode. At greater than 15.0V the battery can overcharge, overheat, and/or go into thermal runaway. Maintaining any ODYSSEY battery at less than 13.5V will bring the battery down and maintain it in an undercharged condition causing sulfation and premature failure. This would not be considered a manufacturing defect failure.

For seasonal applications (non-daily use applications that set for more than 3 days in a row frequently) regular use of an approved maintainer that meets the charge voltage requirements noted in the previous paragraph is highly recommended during the season and/or a disconnect switch. The preferred storage method is to fully charge the battery before storing and disconnect the battery from the application (shelf storage mode). Stored in or out of the application with no loads, the battery would not require charging for up to 2 years at 77°F or until it reaches 12.0V, whichever comes first. The self discharge rate increases significantly for temperatures above 25°C (77°F) and for every 10°C (18°F) temperature increase the storage time to recharge is decreased by half. Charge maintenance is critical to maximizing the life and performance of the battery. Freezing will not harm the battery and self discharge rates reduce significantly at colder temperatures.

It is recommended that the ODYSSEY battery be charged if it is less than 12.65V (about 80% state of charge) when put into use per the ODYSSEY Owner’s Manual (link provided on website Literature page for your reference). Automotive alternators are meant to top off a slightly discharged battery and maintain a fully charged battery. Most standard alternators/stators are not meant to be deep discharge recovery chargers and can become damaged if consistently used like one as well as not fully charging the battery with limited use. A battery discharged to below 80% capacity may not reach a full state of charge, regardless of how long you drive the vehicle using a standard alternator. Typical alternators only run at full amp output for a very short period of time before reaching its charging voltage and dropping into a very low amp trickle charge.

Low amp trickle “charging” a discharged ODYSSEY battery is very inefficient and also can contribute to premature sulfation. Constant duty alternators (usually on heavy duty vehicles) have constant charging current that is high enough for a long enough period of time (when driven/ridden) to get the battery to a full state of charge efficiently. Once the battery is at a high state of charge (at least 85% SOC), an approved low amp trickle maintenance charging is able to complete charging process without prematurely sulfating the battery. The Cyclic Charge Voltage range printed on the top label of the battery is the recommended voltage at the battery from the applications charging system (alternator or stator). At less than 14.1V the battery may not be getting fully charged for infrequently used applications. You can verify the battery voltage by checking the voltage at the battery at least 8 hours after application use (or off charge) and if the battery voltage is not at least 12.84V then the battery is not considered fully charged. Voltage readings taken right off charge or after use (alternator/stator charging) will be inflated and inaccurate so for a true OCV reading, you should wait at least 8 hours before checking the voltage (OCV) with 24 hours being preferred.

Any lower amp (less the 6A for PC680 for example) charger that floats between 13.5-13.8V at the battery and never exceeds a constant voltage of 15.0V in any kind of automatic reconditioning, equalize, de-sulfation mode can be used as a maintainer only provided the charging current is high enough to counteract the parasitic loads of the application and maintain the acceptable voltage in float mode at the battery. With proper charge maintenance, the battery should have a service life of 2-3 times that of the same sized (Ah rated) battery in the same application with the same usage. ODYSSEY batteries have an 8-12 design life and have been known to function successfully well past the design life of 12 years.

Please contact me if you have any questions, concerns, or need further assistance. Sincerely,

Kathy Mitchell
 
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Earthz replaced Odessy

my 680 was about 4 years old including build time and 135 hours flight. It slowly lost crank performance and died last week. I just flew it at least once per week and alternater voltage was always 14.2.
The new earthx 680 cranks like crazy. will it also die slowly like the Odessy without removing and deep discharge like the Odessy died ?
 
My 680 is going on 10 years and still passes a LOAD test. My alternator voltage is always 14.2. It was drained to full dead once when I left the master on. Did a slow charge (less than 1 amp) to 13.8 volts, and has been good ever since.
I never use a maintainer between flights.
 
"Automotive alternators are meant to top off a slightly discharged battery and maintain a fully charged battery. Most standard alternators/stators are not meant to be deep discharge recovery chargers and can become damaged if consistently used like one as well as not fully charging the battery with limited use. A battery discharged to below 80% capacity may not reach a full state of charge, regardless of how long you drive the vehicle using a standard alternator. Typical alternators only run at full amp output for a very short period of time before reaching its charging voltage and dropping into a very low amp trickle charge. "

Never, ever, that I am aware of, have I observed the alternator in my plane behaving in that way. It's capable of well above the 6 amp charging current that Odyssey says the battery wants to see, and is capable of topping the battery off to the set point of the regulator, or about 14.6V. I find the foregoing, honestly, baffling.
 
Possible clue

Thanks Bill,
The alternator is B&C SD-8. Maybe it did not put out the six amps you reference with other loads at 14.2 Volts ? Would that explain the gradual loss of pervformance ?
 
keeping battery charged during functional test

I'm about to start functional test of my panel, in the hangar. How do I keep the Odyssey battery charged up during running the avionics? Trickle charger? Minder? I'm thinking maybe I better us an old car battery and not use the Odyssey until I'm ready to fly it.
 
Has anyone tried this item from Spruce. Thinking about getting it so my Odyssey 680 doesn't strand me somewhere.

POWERALL SUPREME PORTABLE 12V 600A JUMP STARTER
 
Has anyone tried this item from Spruce. Thinking about getting it so my Odyssey 680 doesn't strand me somewhere.

POWERALL SUPREME PORTABLE 12V 600A JUMP STARTER

Why would your PC680 strand you? A fully charged 680 will hold 90% of its charge for six months. If the battery is gradually losing capacity you should have enough warning signs (slower cranking) to replace it before it fails.
 
Well I was tricked into buying a new O PC680 after a year. I wasn’t told there was a year warranty for full free replacement until after I purchased the battery. Yep got rid of the Ultimizer and bought a Noco G3500. Great Great product!!! Resurrect old batteries which is stated in the instructions IN DETAIL ,mAGM , lithium, normal 6 & 12V, small and Large, cold,it’s the Genius series. It does all the thinking for you according to the manual, Love my charger!
Ron
 
Car battery during testing here

Hi all.

When I was doing the testing on all elec-systems after installation (avionics, lights, flaps etc) on both 7's I've bulit, I hooked up a 50-60 amp 12V car battery to the elec system, and let the Odyssey sit disconnected in it's tray.

That way, I could do all the testing I needed without any rush or Odyssey capacity problems.

Just my 2 cents from Norway...
 
I have had 4 PC680 batteries over the last 20+ years. All of them have lasted approximately 7 years. I replaced them because they began to crank the engine with a little less vigor. I’ve only used my charger during this time, maybe 6 times total, on all 4 batteries. I fly frequently, so no need. When I need to do maintenance on my avionics, I use a 12V power supply connected downstream of the master relay, so the battery is taken completely out of the loop. Maybe constant charging doesn’t help? I think that turning on your avionics for programming/maintenance, or any other electrical load, while at the same time having your charger connected might lead to the sulfation you are trying to avoid.

I had an EarthX battery on my fourth RV (RV8) And that is an amazing battery in two ways. It will spin your engine faster than what you’re used to, and it is very light. However, it comes at 3X the cost. I only had that wonderful RV8 for a year, unfortunately, so I can’t judge the battery long term reliability, but I assume 7 years is pretty good for any battery. For me, being able to taxi on your starter (EarthX) has no value, and the PC680 starts my engine just fine. The only real advantage of an EarthX is weight. If I can do what my doctor wants - eat healthier, drink less beer, exercise every day, and loose 10+ pounds, I’ve accomplished what an EarthX would do for me, and I’ve saved enough money to buy a new Odyssey every few years for the rest of my life (which will be longer)!
 
The following "borrowed" from Brian Chesteen. Rejuvenation instructions for a sulfated battery.

... The prodedure is to discharge the battery at the 5hr rate maximum down to ~10v OCV.

Here is the "rest of the story" directly from EnerSys:

The manual reconditioning cycle requires slowly discharging the battery to a loaded voltage of 10.5V then charging the battery ...

Can anyone clarify the exact specifics of this procedure? Do you run the battery down to a LOADED voltage of about 10 or an UNLOADED / OCV voltage of about 10? There's a big difference here. I've tried both recently trying to desulfate my Odyssey PC625.

To reach an OCV of about 10V I have found that I must run the battery down to a loaded voltage of about 5.00V then let it rest for about five hours, after which it rebounds to a pretty consistent unloaded OCV of 10.50V.

However, if after running the battery down to a LOADED voltage of only about 10V, it soon rebounds to an OCV of much higher and when placed on charge, the charger quickly transitions to trickle mode (not good).

Anyone know the exact specifics of Odyssey's intent for this desulfation procedure?
 
Can anyone clarify the exact specifics of this procedure? Do you run the battery down to a LOADED voltage of about 10 or an UNLOADED / OCV voltage of about 10? There's a big difference here. I've tried both recently trying to desulfate my Odyssey PC625.

To reach an OCV of about 10V I have found that I must run the battery down to a loaded voltage of about 5.00V then let it rest for about five hours, after which it rebounds to a pretty consistent unloaded OCV of 10.50V.

However, if after running the battery down to a LOADED voltage of only about 10V, it soon rebounds to an OCV of much higher and when placed on charge, the charger quickly transitions to trickle mode (not good).

Anyone know the exact specifics of Odyssey's intent for this desulfation procedure?

This is going back a few years but:

The procedure is to discharge the battery at the 5hr rate maximum down to ~10v LOADED. For the PC680, that is 2.9 amps max. For the PC625 that is 3.2 amps.

You also must use a charger that can pump at least 40% of the 10hr rate for your battery at 14.7v. The 10hr rate for the 625 is 1.7 amps.

I found that if the battery is gonna recover, it can take several cycles like this to get anywhere. Each cycle it should take longer and longer to discharge. If the discharge cycles are not taking longer than the previous one, either the battery is recovered or not repairable.
 
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I understand the procedure, but where the confusion comes in, as quoted, is that Mike S stated to run the battery down to an open circuit voltage of about 10V, while flyingriki stated a that it should be a loaded voltage.

Correct me if I’m wrong. When you read the voltage with the light bulb connected, that is the loaded voltage. When you remove the light bulb, you will see voltage rebounding, slowly increasing until it levels off at its maximum value several hours later. After that rest period with no load, that is the OCV.

My first experience:
1. Charge with an approved charger.
2. Remove charger as soon as it switches to maintenance mode.
3. Allow battery to rest 8 to 24 hours.
4. Measure voltage. (12.84 is fully charged.)
5. Hook up headlamp and begin draining battery. Periodically measure loaded voltage while the light bulb is hooked up.
6. Remove light bulb when voltage reads 10.50V (as per flyingriki’s post).
7. Measure voltage with light bulb removed. It will be slowly rising. Eventually it rebounds to about 12V several hours later.
8. Hook up charger. (Charger almost immediately switches to maintenance mode. This is not good. Hence, try option 2.)

Option 2:
Steps 1-5 the same.
6. Continue past loaded voltage of 10.50V and drain down to 5.00V in hopes of hitting that 10V OCV point after the battery fully rebounds several hours later.
7. Allow battery to rest several hours until voltage stabilizes at its maximum value.
8. Read voltage after about 5 hours rest: 10.00V.
9. Hook up charger. Charger now stays in charge mode for about 5 hours.

If I understand OCV vs LOADED voltage correctly, then Option 2 is the correct procedure. However, my gut feeling (and maybe some literature from Odyssey?) says that running a battery down to 5V will damage it. Hence my request for clarification.
 
8. Hook up charger. (Charger almost immediately switches to maintenance mode. This is not good. Hence, try option 2.)

12.0 volts is 80% + discharged. If your charger is not going into charging mode with a 12.0 volt open circuit, you need to be looking at a higher quality charger. The CTEC versions are top end and the higher end versions also don't trickle charge. They monitor voltage and only charge when the voltage drops to a certain level and turn off when fully charged. This approach is safe for long term charger connection on SLA batteries.

I think running the battery down to 5 volts is going to do more damage then the recovery procedure will regain. That is a HEAVY deep cycle and eats away a good amount of the lead plates. There is a reason that battery manufacturers tell you NEVER to run a battery below 10 volts.

Larry
 
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Simple procedure works on 30AH AGM Deka batteries-

$15 Inverter of 300W continuous output.
100W 110VAC box fan. High is 10amp draw. Low is about 5, so High for 30AH and Low for small batteries

Any charger with 4 Amp setting that is happy to start above 10 volts. Less Amps is ok, more isn't better.

I find most inverters have a 10.5 ish voltage cutoff and alarm just prior- a fine point.

Discharge and recharge until the time to recharge has gotten longer and levelled out. Takes 3-4 cycles.

Battery still becomes non-aviation by year 5.

Note- I do NOT find Concorde RG-25XCs recover once they lose some AH past year 3, even with the Aviation use only dedicated $200+ BatteryMinder 128CEC1-AA-S5.

The 20AH Deka AGM might be a great sub $100 option to the 680-size Oddessey if the terminal placement is compatible.

Constant/continual float charging is not a proven idea with most any aviation battery and charger combo. It will be fine for a wet acid car battery in storage vs. finding a dead battery, but is typically far from ideal, floating either a bit or far too high. The battery will crank but have degraded capacity if the alternator fails.

A 4 Amp-rate top off preflight or post flight is normal for me- like a mag check- time to end lets you get a feel for the battery.

A real load test, timed to cutoff of say 10.5 volts under load for most of these batteries is what tells the real tale. The way the battery cranks the engine adds the critical electrical connections, each of which can be a problem to trace.
 
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Clarification from Odyssey

Thanks for the inputs. I just got clarification directly from Odyssey:

Those above who state to run the battery down to any kind of open circuit voltage are mistaken. Verbatim from Odyssey: “There’s really no good way to know how that voltage is going to bounce after the load is removed.

From the attached reconditioning procedure guide: the battery is run down until the voltage UNDER LOAD is 10.00V.

1. Discharge the battery using the vehicle headlights or connecting some electrical load to the battery and discharge to 10.0V under load measured with a hand-held digital volt meter. Once 10.0V is achieved, disconnect the electrical load or turn off the headlights or other electrical system or device. ...” The rest as stated above.

There is a big difference between a loaded voltage of 10V and an unloaded voltage of 10V.

Happy reconditioning!
 

Attachments

  • ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf
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Thanks for the inputs. I just got clarification directly from Odyssey:

Those above who state to run the battery down to any kind of open circuit voltage are mistaken. Verbatim from Odyssey: “There’s really no good way to know how that voltage is going to bounce after the load is removed.

From the attached reconditioning procedure guide: the battery is run down until the voltage UNDER LOAD is 10.00V.

1. Discharge the battery using the vehicle headlights or connecting some electrical load to the battery and discharge to 10.0V under load measured with a hand-held digital volt meter. Once 10.0V is achieved, disconnect the electrical load or turn off the headlights or other electrical system or device. ...” The rest as stated above.

There is a big difference between a loaded voltage of 10V and an unloaded voltage of 10V.

Happy reconditioning!

Their story has changed a few times over the years hence the confusion on the subject. I will update my post to reflect the latest suggestions.
 
The only problem I see is that you have to watch the voltage pretty close in order to (1) shut it off at the right time and (2) note the time of discharge which should get progressively longer. It sure would be nice if there was an automatic way to do this.

-Marc
 
The only problem I see is that you have to watch the voltage pretty close in order to (1) shut it off at the right time and (2) note the time of discharge which should get progressively longer. It sure would be nice if there was an automatic way to do this.

-Marc

There are tons of automated battery cycling gizmo's out there. I have no idea which one brings the most bang for the buck.
 
So, would someone please recommend how EXACTLY how (and with what) one should DISCHARGE the Odyssey battery before recharging in order for desulfation to take place. (I'm able to monitor voltage on the main bus through my aux DC power receptacle mounted on the dash).

Has anyone tried the Battery Minder charger which has a built in desulfation function?

What other battery makes are available which may not be as prone to the sulfation issue?

Thanks
 
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