[Beginner]

12 Volt Batteries:
1. If a lead acid battery is competly dead and hooked up to a charger backwards, yes it will change polarity.
2. If a battery is completely dead and you hook it up properly it probally will not draw a charging current for several hours. There is an expination for this that I have forgotten, but if after 24 hours on a charger(outside the trailer) it still fails to charge, its dead.
3. It been my experience that a fully charged battery will not freeze.
4. What happened to your battery could be a one time occurance, unless there was a bad lot of batteries.
5. 12 Volt batteries have a nasty habit of just completely dieing. Usually that is caused by a bad internal connection. If this is the case, it will not draw a charging current.
Interstate used to have a 2 year free replacment warrenty provided you still have your paperwork.

I sincerely hope it didn,t damage the charger in your Airstream.