Odyssey PC680 Battery Problems

[gasman]

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.

[lr172]

Originally Posted by flyer46

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.

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

[PCHunt]

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

[bobnoffs]

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?

[Sam Buchanan]

Originally Posted by PCHunt

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

Originally Posted by bobnoffs

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?

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.

[Richard Connell]

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

[Sam Buchanan]

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.

[RVbySDI]

Originally Posted by Sam Buchanan

Odyssey recommends charging these batteries at 14.1-14.7, I wonder if all RVs are capable of charging at these voltages.

My GRT shows 14.2 VOLTS during flight. I have a Plane Power 60 amp alternator.

[Smilin' Jack]

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

[rzbill]

Originally Posted by lr172

I don't remember the chemistry of the PC680, but I know it is different than flooded lead acid. Larry

PC680 style absorbed glass mat (AGM) or recombinant gas (RG) battery details vs flooded batteries.

Quick summary: PC680s are lead/sulfuric acid batteries like the flooded units however, the physical construction introduces different chemistry (the RG part of the equation)