Questions that come to mind... how many times will this charge batteries? The site says 40. What is the concentration of salt water you need? Is it leak proof? What are the actual care and use guidelines? IE How often do you need to replenish the salt water mixture? How do you 'turn it off' once the batteries are charged? Salt is corrosive... how do you stop the reaction when it is not needed? SEEMS like a good idea but too many un answered questions. I'll stick with my solar for now thanks.