07-10-2014, 11:33 PM
A ceramic or concrete planter makes a good "bunker", especially if it's rectangular and shallow. A sack of sand on top is like an automated halon system. Fire is bound to tear through the sack material.
One problem with metal boxes is that their hinges and sharp edges are just as likely to start a fire as to prevent one. Any type of latch is dangerous, because it might lead to pressure buildup inside the enclosure. A strong sealed metal box with a lipo fire raging inside is basically a bomb. Some of our American cousins store their batteries in ammo boxes, in which case it's vital to ensure sufficient venting by drilling large holes.
Personally, I believe accidents are most likely during initial hookup to the charger, because that's when a tired or distracted brain might accidentally plug something where it shouldn't go, or choose the wrong setting on the charger. I charge up to a dozen batteries in parallel, and my closest calls have always been before the charging actually starts.
One problem with metal boxes is that their hinges and sharp edges are just as likely to start a fire as to prevent one. Any type of latch is dangerous, because it might lead to pressure buildup inside the enclosure. A strong sealed metal box with a lipo fire raging inside is basically a bomb. Some of our American cousins store their batteries in ammo boxes, in which case it's vital to ensure sufficient venting by drilling large holes.
Personally, I believe accidents are most likely during initial hookup to the charger, because that's when a tired or distracted brain might accidentally plug something where it shouldn't go, or choose the wrong setting on the charger. I charge up to a dozen batteries in parallel, and my closest calls have always been before the charging actually starts.