[Q] Question about CyanogenMod 11 topic

Hello, XDA developers. As you may see, this is my first post, but I would like you to tell me what happened with my cellphone.

Something weird happened with my S Advance after I rooted it and installed CyanogenMod 11. I was playing on it, as I changed MinFree settings and overclocked the processor and wanted to check how the performance increased. Suddenly, the phone abruptly shut off without showing the traditional dialogue box that should appear.
When I took the phone to connect it to my battery pack I waited for like 5 minutes and the battery symbol never appeared; after that I tried to turn it on but it didn't work either. As soon as I arrived home, I connected a proper charger to the S Advance and, still, it didn't respond at all.
About one hour later I took the phone and now, when I tried to turn it on (in normal and recovery mode), it would only vibrate for a few seconds, as if it was actually turning on - with the difference that nothing was happening. The only boot mode that I could enter to was the download mode.
Saddened because I thought it was bricked, I came to my room and plugged it to my computer. The screen instantly showed the battery charging sign, and when I turned it on everything was normal. I used my wall charger to try, and it keeps working fine.

I understand that when a phone battery reaches 0%, and you try plug it to a charger you need to wait like 10 minutes to actually turn it on. But in this case was an hour! And when I finally turned the phone the battery was at 0%.
Could you tell me what happened (for potential future ocasions)?