In July, 2005, plaintiff Paul Schanhaar adjusted the plug on a piece of machinery that also included lead-acid batteries and an explosion occurred,apparently causing him permanent hearing damage.
Lead-acid batteries produce hydrogen gas while charging, which is combustible at concentrations in excess of 4%. Products with lead-acid batteries, therefore, should be designed with vent-holes to avoid high concentrations of hydrogen gas.
U.S. District Court Judge Ann D. Montgomery (D. Minn.) ruled last week in favor of defendant EnerSys, the battery manufacturer, in this products liability action, including a picture in her opinion that says it all (see Mem. Op. & Order at p.3). Maybe this illustrates why cars are not designed with combination ash-tray/gas caps?