I have an electric furnace with a digital, battery operated thermostat. The furnace has stopped kicking off at the desired temp. I woke up this morning and the thermostat registered 73 degrees when we always keep it set at 68 degrees at night. I turned it down to 65 to see if that would cause it to kick off and it didn't. Then I turned the furnace off completely, and now it is just blowing out cool air and has been doing this for about thirty minutes. The fan is set to automatic, furnace turned off, breaker is not tripped. I have no idea what is going on.

You have a sequencer sticking. You will need to replace it or have someone replace it.