A car battery doesn't always explode just when being jump-started or charged. There are cases where they suddenly explode due to the installed position, for example, or as a result of a crash, as has been alleged in the probe leading to the Chevy Volt recall.

In any case, automotive battery explosions can cause severe injury and can even be fatal, depending on where one is standing during the explosion. These explosions present added considerations for adjusters who are tasked not only with processing the resultant claims but also in identifying subrogation opportunities.

Let's first examine the anatomy of a typical automotive battery before delving into cases of catastrophic failure. As shown in Figure 1 below an automotive battery, typically of lead/acid construction, is an electrochemical container that produces voltage, which causes electrical current to flow to various components in an automotive vehicle. An outer polymer case (high density polypropylene) acts as a container for an electrolyte (sulfuric acid), six cells and lead plates. Each cell delivers 2.1 volts, with a total voltage of 12.6 volts, at full charge. Vents are installed at the top of the battery to vent gasses formed during the normal charging cycles.