Power one batteries are manufactured in Ellwangen, Germany, at the world's most up-to-date and biggest production site for hearing aid batteries. They are produced on fully automated high-speed lines. The high degree of automation of this  process means that very few manual operations are required - the risk of error is therefore minimal. Each individual cell is tested for its electrical and mechanical characteristics in accordance with its specifications. A highly developed film seal for every cell guarantees that the battery does not dry out or drain prematurely. This long shelf life has been demonstrated in long-term tests even under extreme climatic conditions.