Galaxy Note 5 Battery
There's been a bunch of chatter about a 4,000+ mAh battery though that still hasn't been confirmed and the size of the battery remains up in the air at this point.
The Galaxy Note series is known for its all day battery life. So, if Samsung does decide to kill off the removable battery like rumors suggest, there's a good chance that it will tack on a large battery to offset the change.
A non-removable battery means that Galaxy Note 5 users would be unable to replace the stock battery with an extended one.