Was going to buy a battery, but my son (who's an engineer suggested we check voltage) Checked battery - got 12.5V with car off (not started for 24 hours), 12.5 with ignition on and 14.5 with car running. Also compared the "car off" readings to a new battery, they were the same. We're now going to check the wheel sensor connections.
I wish one of these guys that the battery replacement actually cured their problems had done a voltage check before, but I have yet to run across any post that plainly states such.