I had the very common intermittent battery light. My battery light would come on at weird intervals, with no apparent cause.

Checked battery by conducting a simulated load test
Checked alternator/generator output
Checked battery cables connection
All were ok

Once I turned the car off, it would go away for a while, even close to every few minutes.

Then I noticed that the battery has a bit of acid on top... its getting too hot!
I took off the battery cover, and left it off. It was close to 97 degrees out. After removing the cover I have yet to have the battery light come back on.

Keeping fingers crossed!

 

Good luck!! I had a LOT of corrosion on the top of my battery and had the intermittent battery light problem too. I changed out the negative cable and reset the codes and it's fixed. I left the top off the battery box to keep it cooler; I might oput it back on this winter. The dealership said I might have a cracked battery if it starts doing it again.