This advertisement, located on Genealogybank.com, indicated (as one of our blog respondents mentioned) that the battery was probably used as a "cure" for that which ailed a person.
Date: Monday, August 12, 1850
Paper: Springfield Republican (Springfield, MA)
Page: 2 obtained onGenealogybank.com
It's not often we get proof of our ancestors trying to use "cure-alls." Just goes to show that one never knows what one will discover.