Just my take, not trying to ripple the waves...but...I grew up on a farm in a cold place "on the edge of the prairie" here in CONUS -- Dave, you can freeze a discharged battery...for sure! Been there, done that, more than once ...!!! Once discharged it's like pickle juice or vinegar and the electrolyte's specific gravity drops and it does indeed...turn into ice crystals. Charging a frozen battery is delicate, best to let it thaw first, or watch the amps unless you want an explosion. That would be ugly. And you've likely killed it for the huge CCA load we put on 'em with these engines, regardless.
Read the attached article (below)...or google this phrase, if you want to learn more about it, and to know how to protect your batteries from freezing: "freezepoint of discharged battery". If you read the Wikipedia article, you'll see mention also of sulphation of the lead plates -- hence the desulphate mode on the charger in the earlier post.
-Rich
You won't be reading it today...
Wikipedia is shut down for 24 hrs to protest SOPA/PIPA acts in Congress