2011 V50 battery dies sporadically

[canfie1d]

I've got an intermittent problem that I hope someone else had had as well. I've done a lot of Google searching but turned up nothing so far.

My issue is that occasionally I will go to use my car and the battery is completely dead. I mean so dead that I can't even use the key fob to unlock the doors, the clock loses time, inserting or turning the key in the ignition does nothing at all.

I will say that I don't drive my car every day and when I do it is not far typically. I know that this has a long term draining effect on the battery but I would think that if this were causing my issue, my car would eventually try to turn over but be unable to but not be completely dead. Is that the correct assumption?

The issue occurs seemingly at random. Sometimes not for a month, other times twice in a week.

I've tested the voltage/amperage of the battery and it seems to check out ok.
- Multimeter reads ~14v when running, ~12v when off.
- I've checked for parasitic draw and that checked out OK too at ~50mA.
- I've also had my battery and alternator checked at Auto Zone and both check out ok.
- I left my car for a week with the ground disconnected and the battery held a charge perfectly.

Is it normal behavior for my battery to be that dead over the course of 1-2 nights or do I have something else going on?