Battery ....RIP,......... Death By Polar Vortex??

The weather warmed up into the 30's today. I need to pop the back seat up in the Buick and test the battery. It still isn't happy.
Yep mine tested bad. I bought it January of 2014. 5 years old but I remember the shop I bought it from was glad to get it off their rack. It was pretty dusty so it could have sat for a year or longer in the shop. LOL It's a 840 cca battery and it failed at 654 cca. It's fully charged but only at 12.45v. Time for a new one. Too bad it's a special battery though. (because it's under the back seat and is completely sealed and vented to the outside) I might have to order one.