So, today I turned on my G750JH and the USB on which I boot Ubuntu (without installing) was plugged, the fans were really loud, it didn't concern me much, since it was my first time booting up linux on a USB stick. Anyway, I turned it of, removed the USB stick, booted up Windows 8 (which took 2-3 secs, usually it takes 8-9, I have an SSD) the fans were again noisy as hell again, when I went on to the Desktop, the battery was crossed with a red X, took out the battery and placed it in again and the X disappeared, and then I restarted my laptop, the fans were normal, but the LED light for the battery was blinking green-orange.
I don't know if the blinking was there when I booted Ubuntu and when I booted Windows after it, I only noticed it the second time I booted Windows.
I wrote down in detail above what I did.
It never happened before to me.
ASUS G750JH-T4086D
CPU: Intel Quad Core I7-4700HQ@ 2.4GHz
GPU: Nvidia GeForce GTX 780M
RAM: 16GB
Memory: 1TB + 250GB SSD (Samsung 840 EVO 250GB)
OS: Windows 8 64-bit
Display: Anti-Glare (yup, I'm bragging about it :P)