The PCM is my first thought also. Advance Auto's test supposedly showed a flutter in the charging system, which could possibly be attributed to the voltage regulator, which is incorporated in the PCM.
But the drainage/dead battery hasn't happened in over 3 weeks. It even started with no problem today during the snow here in Atlanta. So the battery had to have decent CCA's.
Still haven't found a voltage drain in my limited time trying. And I'm kinda waiting on warmer weather to start disassembling the interior to get at what electrical issues I know of (rear hatch, left sliding door latch/lock, and passenger overhead courtesy light). And the alarm going off randomly when the van is locked by remote, I have no clue where that's triggered. Hoping the door/hatch lock issues might be the cause. Won't know until I get those remedied.