Yes, that's what seems to be happening with mine. It started off at -535. About an hour later, it's down to -117. A few hours later, it was down to -57. I joked with a friend that it started at Pluto, then onto Venus and now it's in Chicago

I suspect that by tommorrow, it will be back to normal. FWIW, my battery was disconnected for a couple of weeks before I got around to swapping out the alternator.