Strada double wireless... do these symptoms sound like a battery? Or... possessed?

It has always worked well but yesterday I noticed -0- cadence... then it came on / went off / came on again / etc.

Then, I noticed the distance wasn't changing real-time but instead, the displayed figure wouldn't change and then it'd jump ahead all at once and, at the end of the ride the resultant figure was the correct distance-- so, it was accurately keeping track but not displaying in the normal manner.

It actually froze on '666' (6.66 miles) for more than a minute which was pretty funny.