2003 highbeam flicker, electrical issues

I bought my 2003 Impala October of last year and a few months ago started having
electrical problems. These issues initially only occurred when it was hot out (85F+) but
over time seem to happen even when it's cooler (70F+). Every 5-10 seconds or so all
of these things happen at once.

1. The high beams and reverse lights flicker on and off.
2. The low battery warning appears in the 'Message Center' window
3. The warning chime goes off repeatedly.
4. There is a clicking sound coming from both interior fuse boxes.
5. The radio/clock display flickers on and off without audio issues.

Occasionally the car won't have any problems and I'll be able to drive a 35 minute
commute without hearing/seeing any of these issues.

I've also noticed that when it's dark out (I'm assuming once it's dark enough to trip the
auto headlight sensor) the radio display and the headlights/reverse lights won't flicker,
but the warning sound will still chime and the batter warning message will appear.

The last time I took it to the dealership, it was one of those days when it just wasn't
displaying these symptoms. They said there was no error code that showed an issue
at the moment and that they couldn't see anything wrong with the BCM at the time.

Any ideas other than just taking it back to the dealership again when it's actively
displaying the issues?