Battery advise.

[rplarry]

So without any charging what should each batteries voltage be at the moment? Can they actually last 2 years with no charging?

A fully charged lead acid agm or flooded battery will be about 2.12 volts per 2v cell. Or 12.72 total for 6- 2v cells. The ones I bought a year ago were charged at the warehouse and after 3 weeks resting in the back of my truck they were at 2.15v per cell. Not sure why they were so high but they seem to be working just fine for me. I would check those batteries out and if they hold a charge they are probably worth a try. Scrap value right now is about 20 cents a pound so you will be able to get some money back for them when they die.
Hope this helps
Larry

[mtdoc]

FWIW there are some AGMs that claim to have a shelf life of "up to 2 years at 25* C".

Perhaps this is just marketing hype?

Checking the voltage at rest is a good idea.

[niel]

mtdoc,
look at it from a different angle. i am assuming this is until death or 100% dod they are taking it to. so we start at 100% soc and divide that by 24 months and we get a 4.17% monthly rate of discharge. this is even worse than what it is for my sunxtenders which are at 1%-3%/month.

[mtdoc]

mtdoc,
i am assuming this is until death or 100% dod they are taking it to.

Surprisingly I think that is not what they are saying.

"Longer storage life
Unlike conventional batteries that need a recharge every 6 to 12 weeks, a fully charged ODYSSEY battery can be stored for
up to 2 years at 25°C (77°F) from a full state of charge. At lower temperatures, storage times will be even longer."

I don't think it would be much of a claim if after 2 years the batteries were dead.

Of this could be marketing hype. On the other hand Odyssey batteries have been around for a while and have a good reputation in the marine - offshore cruising world- were they get alot of abuse.

Not trying to dispute that most batteries - even AGMs would not be in any kind of good shape after 2 years without a charge - just that at least one company claims their batteries can be stored this long. I have no idea if it's an accurate claim.

[Blackcherry04]

It's hard to compare Odyssey DRY cell technology as it relates to flooded lead acid batteries. I have one in a Jet Ski and while pricey, they do last without attention.

[mtdoc]

True enough. Flooded LAs behave differently than AGM's (like the Odysseys). I believe the OPs question was about AGM's.

BTW I have observed that a fully charged Odyssey's resting voltage does not change after 3 months without charge - but I can't say it's accurate to extrapolate that stability out to 2 years...

[basewindow]

Hi again.

E-mailed the guy and asked him to check the voltage as they are now. He says they are at 12.2 to 12.4. How does that sound? Should I get him to check each individual battery as there are 6 2v?

Cheers,

Cam.

[techntrek]

I would do each 2 volt battery, yes.

[bill von novak]

E-mailed the guy and asked him to check the voltage as they are now. He says they are at 12.2 to 12.4.

That's pretty hopeful - low but may be recoverable.

How does that sound? Should I get him to check each individual battery as there are 6 2v?

If he can do that, yes. You may find one cell at 1.5 volts or something (which means you're out of luck) or you may find them all just above 2 volts, in which case odds are good that they have retained much of their capacity.

[basewindow]

Thanks for the advise. When I asked to have each 2v battery checked, I never ended up with a reply. One can only assume one or more was probably no good. Shame.