The Samsung Galaxy Note 7 as of now has been discontinued, and it was because of battery issues. After the handset was launched many users complained of random heat up even when the handset was not used, and in some cases the Note 7 caught fire, even exploded.
After this incidence Samsung recalled the Note 7 and later on re-launched it again assuming the issue was fixed, the customers were given replacement units, however the replacement units also turned out faulty.
After extensive research, Samsung has now been able to pin point the exact cause of this problem. It was indeed related to the battery. There was a electrode deflection and incorrect positioning of negative electrode tip in the upper right corner of the battery and one more abnormality caused short circuit in the battery.
After this incidence Samsung will be following extensive battery check protocol for every devices launched in the future. They have also improved safety standard of their batteries.
Check the video for more details
https://www.youtube.com/watch?v=6s4uqr1serU&feature=youtu.be