A fully charged NiCad pack can deliver a 200amp spark when shorted. A club member in one of my flying clubs who ran a hobby business out of his van left a small foam airplane in the van on charge while he went in the house. a neighbor kid banged on his door to tell him his van was smoking. In spite of the fire department arriving quickly it was a total loss including $10,000 worth of hobby merchandise. I was told the plane battery was only a few hundred mah.