This thing will probably go viral, so here it is. A modeler was charging a largish LiPo in his garage, left it unattended for awhile, then heard the boom. http://helifreak.com/showthread.php?t=291770 John Edit: In skimming the rest of the thread, some people thought it was BS. Others suggest that other accelerants (e.g., spray paints, stored gasoline...) could have contributed to the explosion once there was fire. Nevertheless, I think there is little doubt the LiPo caught fire. The explosion itself could have been more like what happens in a potato cannon.