This white paper explores the use of bobbin-type lithium thionyl chloride (LiSOCl2) batteries to power remote wireless devices for up to 40 years. Such extended battery life demands a superior quality battery with a self-discharge rate of less than 1% per year. This claim must be verified by actual results from the field and through long-term testing. Tadiran has continually tested batteries for over 26 years, resulting in a huge database that accurately predicts long-term battery performance.