LiFePo4 is one of the safer lithium battery technologies, but not quite as safe as Lithium Manganese Oxide (which are used in the fairly large Torqueedo trolling motor batteries). Lithium Cobalt Oxide is the dangerous one, but also the one with the highest energy density (and probably the cheapest one too, since hobby batteries use this one).
I have a Torqueedo LiMnO pack that is 500 watts, and I do sleep next to that on our sailboat. I would be *ok* with LiFePo4, but no way would I spend the night with LiCoO, even if she bought me dinner.
