Yes, I am worried this battery is pretty much a goner. I check the next day and it was at 12.4V and 70%. I let it charge to 100% but haven't touched it since.
With the motorcycle the battery tender was the ticket. It worked really well at keeping up the battery and was pretty easy to deal with the 1-2 times a month I used the motorcycle. The really problem for me with the battery tender on this car is that it's my daily driver for at least Monday thru Friday. On the weekend it either comes out for a nice long cruise or sits in the garage if we need the SUV. Connecting and disconnecting the tender everyday during the week is going to get old very very fast!
I've given heavy thought to selling this car and just getting something else but the car isn't worth dirt right now. It seems I can only get a little over half the purchase price and it's only 2 years old with ~20K miles.