Batteries that have not been used for a long time discharge themselves and, in addition, their plates can be sulphated. If these batteries are charged with a quick charger, they do not absorb the charging current or, due to the so-called surface charge, are too early "fully charged". They seem to be faulty. But before considering these batteries as faulty, they should be checked.
Check electrolyte density. If in all cells the electrolyte density differs by no more than 0.04 g/ml, then this battery can be charged with a standard charger.
If the density in one or two neighboring cells deviates more significantly (more than 0.04 g/ml), the battery has an internal short circuit and is faulty.
After charging, test the battery under load. If it does not achieve the specified values, then it is faulty.
To prevent battery aging, recharge a stored battery every three months.