I wouldn't get my hopes up either, there is a point where batteries enter a state of what is essentially "permanent" discharge where there is actually a chemical change in the way the anode, cathode, and electrolyte behave. You can try to prod them back into working, but it would take special equipment, and even then, you run the right of a thermolytic reaction that will cause the battery to essentially become a bomb, so I would advise against it, unless you really, really know what you are doing.