Safety tests of lithium 9-volt batteries for Navy applications

COTS batteries are relatively inexpensive, readily accessible, and extremely versatile. These attributes allow the military to save time and money during the research and development stages. Of these COTS batteries, a 9-Volt (9 V) lithium/manganese dioxide battery is the subject of this paper. This 9 V battery has the ability to provide a low magnetic signature, which is very important to the Navy for many applications, Also, it is Underwriters Laboratories (UL) listed at the unit level; however, these UL tests cannot be directly related to the safety of these 9 V batteries when they are combined in various series and parallel configurations. Naval Surface Warfare Center (NSWC) Carderock was tasked to rate the safety of several such specialized battery packs. It was found that packs consisting of two 9 V batteries in parallel were relatively safe, experiencing no violent behavior. Battery packs with six 9 Vs in parallel vented and deformed the 9 V batteries, but no smoke or flames were noticed. A battery pack with thirty 9 V batteries, 2 in series with 15 legs, experienced venting, smoke, and flames under certain circumstances, After testing, the six and thirty 9 V packs were required to include the addition of various safety devices.