- take two flowerpots. flowerpot 1 is the base, flowerpot 2 is the top.
- cut a notch out out of the rim of flowerpot 1. this is for lipo charging wires.
- fill flowerpot 2 with sand.
- cover flowerpot 2 with a sheet of thin plastic, something like grocery bags.
- secure the plastic around the rim.
- attach a piece of chickenwire to flowerpot 2.
- put the batteries in flowerpot 1.
- place flowerpot 2 upside down over flowerpot 1.
- if the batteries catch fire, the plastic will burn and the sand will flood the batteries in flowerpot 1.
It would be nice to have this setup sitting on the porch and just run the charging cables outside.