12 hrs and down to 12.73 seems a bit soon to me to be that low. I would expect more like 13.2 next day and 12.x the day after that. Be prepared to see the SG in the "fair" zone, and the need to do some "recovery." It takes a while to bring them up to good shape but you can still use them. In fact using them is the best way to bring them back up!
EDIT I see in a note on testing the T-1275s that 1 hr 15 min after stopping the charge with batts at 14.94, the voltage had fallen to 13.43/13.40 Then next day voltage was 12.93/12.90. It falls more each day of course, but very slowly after reaching its real voltage at 12.7ish in a couple days.
