[scottyb]

Plates left exposed to the air will immediately sulfate. These plates are no longer active in the exchange of electrons.
The percentage of plates left exposed is equal to the capacity percentage lost.
The longer a battery sits and is not re-charged the more damaging sulfation build up there will be on the plates.
The charger is looking for approx. 63v for the cut off voltage. Check the pack under charge to see if it is still able to reach the charger cut off voltage... Even if it does, I fear your capacity will be diminished.
This may prove an expensive oversight