Extra PC680 - Sell or Keep

Returned a bad battery to batterymart.com under warranty and received a new replacement. Sure like working with businesses with integrity! But, now I have two as I bought one so I wouldn't have to wait to fly. I like having spare maintenance items on the shelf but don't know how long a battery can sit. Sell or keep?

I'm no chemist or battery expert, but from what I have read -- I think it will die just as quickly sitting on the shelf as in your airplane. If it were me, I'd sell it.

I agree... sell it. I had PC680 in my plane since 2012 and have just changed it out. The 680 never did turn the prop with gusto even when new and fully charged. I definitely did notice that if it had been a couple weeks since last flight it was even more sluggish. I'd bet it wouldn't last long on the shelf.

Paul 5r4 said:

I agree... sell it. I had PC680 in my plane since 2012 and have just changed it out. The 680 never did turn the prop with gusto even when new and fully charged. I definitely did notice that if it had been a couple weeks since last flight it was even more sluggish. I'd bet it wouldn't last long on the shelf.

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Most sealed lead acid batteries, like the odyssey, have a very low self-discharge rate relative to standard flooded lead acid batteries. Most SLA batteries (i.e. AGM technology) can go 6-12 months with very little loss in capacity. A flooded battery would likely be at 50% capacity or less in that time frame. I believe the loss is on the order of 1-2% per month, where a flooded is .5-1% per day.

I would expect you had other issues, such as a current drain somewhere on your aircraft or a high resistance somewhere in your starter circuit or a defective battery.

SLA's can sit for a long time and be ready to go, assuming you don't leave them on a trickle charger, as that will destroy them.

Larry

Some information from the Odyssey battery company

I recently emailed EnerSys, the company that makes Odyssey batteries. Here's some of the information they provided which may be helpful:

ODYSSEY Battery basics. ODYSSEY batteries are an AGM Lead Acid battery however the TPPL (Thin Plate Pure Lead) technology requires that the batteries be charged at a higher current than most batteries and maintained at a slightly higher voltage than other standard lead acid batteries on the market. They are also truly dual purpose batteries that can be used for both cranking and deep cycling. Due to the technology, proper charge maintenance is critical to maximizing the life and performance of the ODYSSEY battery.
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 (for example 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 warrantable 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 before charging is required. 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.

airmel said:

...Freezing will not harm the battery and self-discharge rates reduce significantly at colder temperatures.

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Thanks Melinda. Maybe keeping it in the freezer is an option. Next to the proseal . Certainly can't keep it in the hanger in Texas!

larrynew said:

Returned a bad battery to batterymart.com under warranty and received a new replacement. Sure like working with businesses with integrity! But, now I have two as I bought one so I wouldn't have to wait to fly. I like having spare maintenance items on the shelf but don't know how long a battery can sit. Sell or keep?

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That battery can sit for years and still be serviceable for many tasks. I had one under my workbench that has been out of the plane for six years after it was in service in the RV for about six years. That 12 year-old Odyssey will still crank the lawn tractor and performs well for when I need a 12v power supply. I'm now using it for running an electric fueling rig for my biplane.

If you just need a utility battery for the hangar or work bench it will last for a very long time. Just charge it a couple of times a year.

I'm in San Antonio (53T) in need of a PC680 if your looking to sell it before I order one.

David one two ten seven 89-08 four eight.

David,

Email sent.

Thanks,
Larry