I have quite a few LiPo batteries, very energy dense, very high discharge rates but very charge sensitive.
The 'exotic' bike and car batteries do have regulators and charge balance controllers built in so that they don't explode the first time your regulator dumps a few more volts than intended into them.
The old damaged ones have given much fun as they aren't that safe to transport (I store them in a high temperature fire proof bag in a steel box) so I just kill them by puching a little hole into them. Sometimes you just get a jet of fumes come out, other the fumes ignite into a very realistic imitation of a blow torch just at a slightly higher temperature.
Great fun
