The development of the storage battery was based in part
on a nostalgic desire for the glory days of Menlo Park. Edison
poured quite a bit of his energy into the project, and he refused
to listen to detractors who labeled it a folly like his ore-milling
project. And he was correct in that the battery did become important
to industries and consumers, it was just not in the way that he
had anticipated or perhaps desired. Because they were known for
their long life and reliability, they were most often used as stand-bys
for power plants, railways, miners' lights, and military equipment.