Battery Questions

[winsa12]

Someone is selling (4) 12 V Trojan batteries that have been sitting unused for a year. I need new batteries and part of this build is to spend as little as possible.
1. Assuming they were not on a charger/maintainer over the winter will they be good? How can that be tested?
2. Is there anything adverse (other than lower range) of doing 4-12's instead of 6-8's in a 1989 36v to 48v Club Car with a 400 amp controller upgrade?

[NoleFan4Ever]

How old are the batteries and what do they read when you test them with a digital volt meter.

[winsa12]

1 year (supposedly never used) and I have not visited them yet. I guess I am looking for what should they test with a voltmeter?

[NoleFan4Ever]

See Below...

[Sergio]

I think based on the unknown history of the batteries, the only way to really know their state is to fully charge them and put them on a discharge machine.

[ThreeCW]

Batteries that are discharged (some say below 80% State of Charge) are prone to "sulfation". Depending on how long batteries are left in a sulfated state and their Depth of Discharge will likely determine if the "sulfation" permanently damages the batteries or if the "sulfation" is reversible. I have seen new automotive batteries that were left unmaintained for a number of months that were no longer able to accept a charge, likely due to sulfation.

As Sergio suggests, attempt to fully charge them. If the batteries are not able to acheive a 100% State of Charge (12.73 volts stabilized after being disconnected from the charger for 12 to 24 hours), then there could be irreversible damage to the batteries from sulfation. If they acheive the 100% State of Charge, then consider having them discharge tested at a battery shop.

Battery age can be "poorly represented" by those selling them. Make sure to check the date codes on the battery tops or on the posts to verify their age.

Sergio - considering that a new battery takes a significant number of charge cycles to fully develope its discharge potential, will a discharge test be valid in this circumstance? Is there a risk of damaging a new battery by discharge testing it due to being deeply discharged?

[Sergio]

I would not trust anyone that let batteries sit for a year to tell or even know the truth about their condition.

The main thing to avoid with new batteries is the discharge rate being too high.

The discharge machine depending if it is a 12v or 48v (best for 12v battery pack) will place either a 75Amp or a 56.25Amp load on the batteries.

That is a mild load and It will probably give you a better estimate than just taking a voltage reading.

[winsa12]

Thanks for the help guys.

In further conversations since I originally asked the question here I learned he claims he kept them charged.

I'm trying to weigh if the risk is worth the reward- $400 for $1,000 new cost...