Title: Maybe improved, maybe not.
Review: January, 2012 review notes company has switched back to original formulation to give usage life advertised. I began using five in our home smoke detectors in June, 2010. By September, 2011 one had failed and the remainder failed by November, 2011, all in the middle of the night I assume due to lower temperature at that time. I would be leery of buying these until there are more reports confirming at least a five year usage life. I will not be buying any Ultralife batteries until then. Too bad since battery says they are made in USA.
Is this product review negative?