Honda Civic Forum - Strange intermittent electrical issue on 01 LX Coupe

So a few months ago while I was driving home my HU kept cutting off for about half a second. I figured it was just the HU being stupid/old. As I got closer to home something on the dash cluster caught my eye, the SRS light was on momentarily. Then I noticed that at the same time the radio went off, the speedo and tach needles dipped, then the lights came on as if the car had just been started. This continued a few more times until I was home. At no point did the engine hesitate or stutter during all of this.

Once I got home, I began turning everything off and getting ready to shut the car off and decided to test a few things. So I turned the fan on full, turned the stereo back on kind of loud, and rolled the windows down/up. This managed to cause the cut out, but it also caused the engine to hiccup, as it was only idling and not actively powering the car along.

I shut the car off and went to my apartment and tried to research things, decided to go to Autozone to get the alternator and such tested. When I went back down to the car, it acted like the battery was dead. Turn the key, cluster barely lights up, no action from the starter at all, etc. Dome lights wouldn't come on, no power at all. Popped the hood, checked the battery terminals, which as I knew were clean and tight, no obviously loose wires, etc. get back in and try to start the car. Now it cranks, but refuses to turn over. Tried a few times cranking upwards of 10 seconds, but no start. I went back to my apartment for a few debating my situation, then went back down to try one more time to start the car. Fired right up as if nothing were ever wrong.

Drove to Autozone, the guy hooked up a tool to the battery, battery passed tests. Had me start the car. Alternator/starter passed. He suggested maybe the coils were of issue, possibly a few other ideas, I drove home wondering what the hell could be wrong.

Since then I've had the issue crop up 3 or 4 more times. I had a friend of one of my IT coworkers who is a mobile mechanic (same guy that took care of my front driver side wheel bearing) check some things, he tested the battery, looked around under the hood, messed around under the dash on the drivers side checking relays, etc., but was stymied. The issue happened this morning again, it was raining so I didn't bother to get out and muck about under the hood. After numerous turnings of the key and getting nothing, etc. the car slowly seemed to respond better and better until suddenly everything was full power and it fired up. The last time it did this (about a week ago) popping the hood and then shutting it kind of hard seemed to help, as it restored full power, and then I had to play at cranking forever until it finally decided it was ready to turn over.

Every time this happens the HU is reset, the OD and trip OD are not affected.

So the question is, has anyone had this happen before? Any ideas as to what the hell is going on? Weather doesn't seem to matter, it's happened both when hot as hell and when fairly cold, both morning and evening. It doesn't seem to be caused by bumps in the road either, I've watched for things like that when the radio starts cutting out which is why it's so damn annoying, there doesn't seem to be any specific cause, it just happens whenever it wants.