Electric submarines have pretty large batteries with very low-voltage cells but where a cell is big enough to deliver huge amounts of current. Completely safe t

Electric submarines have pretty large batteries with very low-voltage cells but where a cell is big enough to deliver huge amounts of current. Completely safe to touch with bare hands, even wet hands, but if you drop a metal tool that shorts a cell, the tool may be vaporized and the resulting metal fumes are very dangerous.