The safety and reliability of batteries are closely related. Examples are given to demonstrate how changes made in battery materials and design parameters to improve either safety or reliability may also enhance other characteristics. In one example, replacement of the glass in the glass-to-metal seal of Li/SO2 cells to improve reliability also eliminated a serious safety problem associated with discharged cells. The second example relates to design parameters in Li/SOCl2 cells for increased safety. A Taguchi analysis indicated several parameters affected safety upon reversal. The indicated levels of these parameters for improved safety also suggest improved reliability, although the long-term reliability studies have not yet been completed.