Not a battery expert but batteries should not freeze up Scott. Batteries should be charged or trickle charged if not used for a long time like storage. Lead Acid batteries can bad as you have learned. Good thing is Wal-Mart has these fairly inexpensively. Bad thing... who likes to spend money on batteries? All you can do is what you stated in your post, charge the battery and see if it holds a charge. If there is a lot of crud on the bottom of the battery, the internal plates may be shorted together and the battery pretty much useless. I'm sure there are others here that deal with batteries more than me...just my two cents. Good luck buddy.
Hoppes