Batteries

50+ year battery consisting of nickel and iron plates in an electrolyte of Potassium Hydroxide (similar to lye - which I'm guessing you could substitute).

Thomas Edison drove an electric car a hundred years ago. The batteries he used are easy to build and are still operational. Search for 'nickel iron battery', 'edison cell' or 'nife battery'. See http://www.beutilityfree.com/content/ I have a document on how to build one I need to dig up.