[Al Skierkiewicz]

Matt,
When the battery swells unchecked (like not putting it in the snow) the case seams usually come apart and the battery acid oozes out. If the temperature rises very rapidly, a far more violent case failure will occur. Regardless, the battery uses sulfuric acid. While this is somewhat diluted (typically about 30% acid) getting in your eyes nose or mouth (or other sensitive areas) will not be something you are likely to forget. If you get acid on your clothes, you may not notice a problem until after they are washed. Many fabrics will dissolve where they are touched by the acid.

In this particular case, only one cell will likely suffer from the damage, the one closest to the corner. If that cell swells internally, it may push against the plates in the next cell and cause a short there.