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luv2flypilot

Well Known Member
I have had to replace my Odyssey PC680 battery 6 times over the last 5 years. The last go around I only got 8 months before it would not produce enough cranking amps to start the engine. I use their charger/maintainer they claim will not hurt the battery if left connected to the battery indefinitely. I have even purchased another Odyssey charger to eliminate the possibility of a bad charger. I seem to not get much warning when the battery goes bad and does not seem to have much cranking amps. The battery indicates 100% charged on the charger when the battery seems to stop providing enough power to crank my engine over for start. I do have a higher compression engine (9 to 1) which makes it a little tougher to turn the prop than a standard build. Has anyone else had any issues with these batteries? My alternator seems to be putting out just fine, however I need to try and get reading at the battery for voltage and current when the engine is running to verify exact readings. I have also spoke with Odyssey however they don;t seem to be a whole lot of help and not to prompt on getting back to me.

Here are some of the specs on my airplane:

RV-7A, Serial #70839
Registration: N507RV
Engine: IO-360-B1BC3, 9 to 1, Roller Lifters, Flow Matched Cylinders, Dual Unison LASAR Ignition, Sky-Tec Starter, Silver Hawk Fuel Injection
Prop: Whirlwind 200RV, Aero Technologies P-520-036/A Governor
Panel: Vertical Power VP-200, AFS 3400EE EFIS, GNS-430W WAAS GPS, GPSMAP 496, SL30 Nav/Com, GTX-330 Transponder w/ Traffic, PMA9000EX Audio Panel, DigiFlight II VSGV Autopilot, Smoking Airplanes SA-101H Smoke System, Sony XAVW1 DVD/Entertainment Unit w/ Sirius Radio & Two Exterior Cameras
 
Going on 6 years on a PC680 on my RV9. Absolutely no problems. I use a $20 maintainer from WallyMart. Yes, I know it might not be optimum, but it still is withing a tenth of a volt of the "Odyssey charger". Battery still cranks O320 with vigor.

I'd be looking at the setpoint on the voltage regulator (set too low), or a phantom load. If a phantom load keeps the battery at a state of discharge, it will not last long. While flying, I normally see 14.3 VDC when the alternator is running. That might be slightly high, but it is in the right ballpark.
 
luv2flypilot said:
I have had to replace my Odyssey PC680 battery 6 times over the last 5 years. The last go around I only got 8 months before it would not produce enough cranking amps to start the engine. I use their charger/maintainer they claim will not hurt the battery if left connected to the battery indefinitely. I have even purchased another Odyssey charger to eliminate the possibility of a bad charger. I seem to not get much warning when the battery goes bad and does not seem to have much cranking amps. The battery indicates 100% charged on the charger when the battery seems to stop providing enough power to crank my engine over for start. I do have a higher compression engine (9 to 1) which makes it a little tougher to turn the prop than a standard build. Has anyone else had any issues with these batteries? My alternator seems to be putting out just fine, however I need to try and get reading at the battery for voltage and current when the engine is running to verify exact readings. I have also spoke with Odyssey however they don;t seem to be a whole lot of help and not to prompt on getting back to me.

Here are some of the specs on my airplane:

RV-7A, Serial #70839
Registration: N507RV
Engine: IO-360-B1BC3, 9 to 1, Roller Lifters, Flow Matched Cylinders, Dual Unison LASAR Ignition, Sky-Tec Starter, Silver Hawk Fuel Injection
Prop: Whirlwind 200RV, Aero Technologies P-520-036/A Governor
Panel: Vertical Power VP-200, AFS 3400EE EFIS, GNS-430W WAAS GPS, GPSMAP 496, SL30 Nav/Com, GTX-330 Transponder w/ Traffic, PMA9000EX Audio Panel, DigiFlight II VSGV Autopilot, Smoking Airplanes SA-101H Smoke System, Sony XAVW1 DVD/Entertainment Unit w/ Sirius Radio & Two Exterior Cameras
Click to expand...

I have a very similar plane, yet no problems whatsoever with my PC680. The notable difference between you and me is that I almost never use the charger. Not sure why you would have to unless you spend a lot of time running the avionics with the engine off. I seem to remember a number of cases like this desribed on VAF where bad batteries correspond with regular use of the charger. Screwy I know, but hey, who charges up the battery on their car every day? No need for it unless something else is wrong.
 
If I flew my RV every day, I'd agree with erich. But as the battery ages, slow sulfation takes its toll. If not flown for a week (or maybe a month) the actual charge in the battery can drop from internal currents that slowly discharge the battery. That is where a maintainer (not a simple charger) earns its keep.

And yes, I have one car that I drive very infrequently (sometimes on a two week interval). It has a seven year old battery that I sometimes put on the same style maintainer I use on my RV. Still cranks just fine.
 
OK, this may sound harsh but take it with the warm fuzzy intent.

The definition of stupidity is to keep doing what you are doing while expecting a different result.

I suggest that you might need to carefully check your alternator and regulator, or other charging devices. You should not kill batteries like this. Phone Odyssey for some help.
 
Replaced my Odyssey battery thinking it was going bad, but not much improvement with a new Odyssey. Was about to return what I thought was a bad battery when I, along with my mechanic, checked the Skytec starter. Sure enough that was the problem. Replaced the starter and the battery works like a champ.

Just a thought.
 
Battery maintainer

I was starting to see a weakness in my less than 2 year old battery a year ago. After reading stuff on here I stopped using the battery maintainer (not Odyssey model) and everything has been find since, not more signs of battery weakness.

I fly nearly every week and more often than that now that the weather is better.

Cheers
 
Odyssey Charger

Luv2fly,

I offer the following assuming that you can detect no "cold" voltage drains.

What I, and several others on this site have found, is that keeping the Odyssey charger connected at all times prevents the charger program from going through a high charge voltage cycle designed to break up accumulated sulfate. The battery must be discharged by a significant amount before the charger steps up the charge rate sufficient for this process to take place--and connecting the charger after a flight, when the battery is fully charged, prevents this cycle from ever happening. This in turn significantly shortens the battery life. This is also why, in many cases, Odyssey's "rejuvenation process" works. I know that the charger info says that it can be connected continuously, but since stopping this practice, my batteries have been much happier and last far longer.

Oh, and by the way David, what you describe is the definition of insanity--not stupidity--neither of which applies in this situation!

Cheers,

db
 
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My friend's RV-8 was completed in 2010 with a PC680 battery purchased early that year. It's got a 9.2 compression IO-360 with Skytec lightweight starter and a Plane Power alternator that charges at about 14.5 volts. The battery is still going strong after 4 years and he never uses any kind of external charger or maintainer on it. The aircraft is not flown nearly as frequently as it used to be, maybe once a month when it used to be flown weekly/several times per week, but it still always cranks right up even after sitting for a full month.
 
My results are the same as others - better performance without using a tender. My flying (usually at least once/week) has slowed recently mainly due to work and secondly due to starting my -10. 2 weeks between flights, no tender, no problems - this PC680 since Nov '12.
 
A PC680 will hold a charge for 2 years if the average temp is 77f and stored with a full charge. There is NO NEED to place this battery on a maintain charger unless the open circuit voltage drops to 12.00 volts at the posts.

My 680 is going on eleven years with no problems. Sits for many weeks between flights at times. And has had one FULL discharge. Master left on. But when the master is off, the battery IS off line 100%. My alternator is set at 14.2 volts.
 
flyer46 said:
If I flew my RV every day, I'd agree with erich. But as the battery ages, slow sulfation takes its toll. If not flown for a week (or maybe a month) the actual charge in the battery can drop from internal currents that slowly discharge the battery. That is where a maintainer (not a simple charger) earns its keep.

And yes, I have one car that I drive very infrequently (sometimes on a two week interval). It has a seven year old battery that I sometimes put on the same style maintainer I use on my RV. Still cranks just fine.
Click to expand...

This is not really true. Sulfation only occurs when the battery has a charge lower than 80% and is for Lead Acid batteries. I don't remember the chemistry of the PC680, but I know it is different than flooded lead acid. Lead Acid batteries will typically lose as much as 1% of their charge per day and need a maintainer or an occassional charge when not used.

I am with the last poster, unlike lead acid the PC680 has an incredibly low internal discharge rate and therefore doesn't need a maintainer. It is possible that the unique chemistry is damaged by the constant float voltage, unlike a lead acid battery.

To the OP, I would also be checking for a current leak somewhere. If it is not the maintainer destroying your battery, my second guess would be a current leak.

Larry
 
I installed a Tempest TR-22-12 battery in 2009. Just ordered its replacement. $49

Did not leave it hooked up to a battery charger, but did top it up from time to time if the plane sat around for more than about a month. 5 years is good battery life.

I think the original was about$38 if memory serves.

Lots of other brands than Odyssey. Several at about half the price. My guess is that a lot of them are made in the same factory, just with different labels put on them.

Yep, I'm a skeptic!

YMMV
 
holy cow!,
had not heard of tempest batteries until now. $42 for an apples to apples tempest compared to a 680? really? how come everyone isn't using one?
 
PCHunt said:
I installed a Tempest TR-22-12 battery in 2009. Just ordered its replacement. $49

Did not leave it hooked up to a battery charger, but did top it up from time to time if the plane sat around for more than about a month. 5 years is good battery life.

I think the original was about$38 if memory serves.

Lots of other brands than Odyssey. Several at about half the price. My guess is that a lot of them are made in the same factory, just with different labels put on them.

Yep, I'm a skeptic!

YMMV
Click to expand...

bobnoffs said:
holy cow!,
had not heard of tempest batteries until now. $42 for an apples to apples tempest compared to a 680? really? how come everyone isn't using one?
Click to expand...

Another option is the Panasonic, etc, wheelchair batteries. I used a couple of them (~$40) before going to the PC680 eight years ago:

http://thervjournal.com/battery.htm

But the take-away I've seen from all the PC680 threads the past several months is....don't use a trickle charger on these batteries. The batteries that haven't been continuously charged seem to have a long service life, the charged ones often fail prematurely.
 
I inadvertently wired the voltage sense for the alt external regulator to the battery bus rather than the main bus when I was building.
If I ever went more than a week without flying I'd have a weak battery, 2 weeks and a completely dead battery. I'm amazed it came back to life at all with charging.
Turns out the voltage sense drains a few mA even when everything's shut off.
Moved it to where it should have been all along. Never had a flat battery in 5 yrs since. Never trickle charge. Might be worth checking, I know others have made exactly the same error.

Cheers
 
new PC680

Installed the new PC680 today. It has a date code of 3-14 so it could be up to three months old right out of the box.

The doc booklet packed with the battery stated that 12.65v is a battery ready to be put into service. My battery measured 13.2v after spending 2-3 months in the box.

There is an interesting paragraph in the Odyssey doc that may explain why some have been told they need a trickle charger. It seems some of the V-twin motorcycles are ridden at such low rpm that the battery will discharge faster than the slow-turning alternator can charge. Odyssey recommends a charger for those applications.

But unless there is a significant keep-alive load on our batteries, the doc states trickle charging is not needed for applications like ours. The PC680 should hold a charge for a very long time. Odyssey recommends charging these batteries at 14.1-14.7, I wonder if all RVs are capable of charging at these voltages.
 
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I have to agree with what David B stated,
I too just replaced another Odyssey PC680 the second one since I have had the electrical system operating back in 2012. This one only lasted from November 2013.

I too was told exactly what David say.... the battery does not need a tender on a fully charged battery... so I am not connecting anything unless I don't fly for a couple months but I don't see that happening.

Smilin' Jack
 
gasman said:
A PC680 will hold a charge for 2 years if the average temp is 77f and stored with a full charge. There is NO NEED to place this battery on a maintain charger unless the open circuit voltage drops to 12.00 volts at the posts.

My 680 is going on eleven years with no problems. Sits for many weeks between flights at times. And has had one FULL discharge. Master left on. But when the master is off, the battery IS off line 100%. My alternator is set at 14.2 volts.
Click to expand...

I too have a PC680 and as stated above, it only gets the charger if

1.) I flip the master on and see < 12 volts

2.) have the avionics on for an extended period

It goes against what Odyssey says, but I've only heard of the PC680 dying young when constantly on a trickle charger.
 
It's hard to believe you have had that much trouble with your Odyssey batteries. I am on my third one in 10 years. I generally replace every 3 years or so just because. All of our RV's in my area are also running Odyssey batts, I haven't heard of anyone having trouble either. You need to look at the possibility of other problems. First, not knowing how old your kit is and not knowing when you purchased a wiring kit, you need to see if you have the bad cables that were delivered a few (4 or 5) years back. Van's (or their vendor) used the wrong die and under-crimped the #2 gauge wires in many wiring kits. I helped a friend build a '7A. All was well until a starting problem developed after a few years and was traced to under-crimped wires. He had also replaced his battery thinking that was the problem. After cutting of the nice heat shrink tubing you could clearly see the wire move inside the terminal end as the crimp was not deep enough. You need to perform a voltage drop test of your starting system. It's easy to perform if you know how to do it. You can look it up on google or contact me and we can go over how to do it. I simply cannot believe you have had such poor service with your batts.
Rex 530-945-9000
 
680

I am on my second Odyssey over 6 years but the first one is still starting my lawn tractor on a regular basis. I don't use a maintainer and even if the airplane sits for 2 or 3 weeks, the battery cranks just fine.... no issues. I will buy another when the time comes.
 
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