The problem is faced when phone is connected to pc and somehow a condition is changed.
Drop sometimes is just by connecting, sometimes by turning MTP off, Sometimes Turning USB Debugging off
I called up Motorolla for a Solution and they replied to tell me to do a factory reset. I didn't believe them but tried anyway and viola, it worked!
Performing a factory Reset (in some cases) solves the problem of sudden battery drop to 0%
Note: This is not a permanent solution, There is a chance for problem to come back, but also there is a chance that your phone will not face the problem!
It's been a month after reset, I haven't seen the problem again!
Hope it helps you too!
Share your Experience too! Weather it worked for you or not!