This exact scenario was accomplished at a cold storage company in Long Beach California. When we arrived the forklift battery was in very poor condition. It Mechanical Workshop Safety Ppt had been sitting for years on a palet because the company was told that it was no good and they needed to replace it with a new one.
Like most companies though they were not aware of a way to bring it back to a new condition American Run Multinational again. In fact they believed that this task was an impossible one.  
Low and behold though we put our piece of equipment on the battery and it would not accept a charge at all. In fact it only took a few amps to bring the voltage up to 60 volts! Gradually the voltage was brought down by the machine and over a two day period the it would finally accept a full charge on their own charger.  
It was left on their charger over night on equalize. The next day when we returned the all the acid readings where right where they were supposed to be and we did a load test which was found to be 94% of a new. It continues to be used back in service for a full shift to this day. And it was a battery that was fixed with no cell changes. 
All over the world now forklift batteries are being restored and used for twice their life instead of being discarded or scraped. Doing this helps make companies more green and promotes the saving of the environment. Also companies can save a significant amount of money.

By master