A screenshot of the battery usage with the new battery I bought a few days ago. After heavy usage using Wifi assisted GPS with Maps navigation with screen permanently on for over 4 hours, and using Cinema FV-5 to record some nice fantastic 4K videos aswell.
In contrast to my old battery screenshot taken from 19th September 2014, after which the battery wanted to give up after 5 hours.
By the time I had travelled to the shop to change my old battery, the battery had bloated itself up to approximately 1.5 times its normal size, and when I showed the battery to the shop assistant he asked me if I keep the charger plugged in when the battery is full & I told him that I do if a charger is nearby.
The battery drain had started a few months ago when the battery still looked like a normal sized Samsung Galaxy Note 3 battery, so I wouldn't suggest you should wait until it's bloated to change it, because the battery drain you receive compared to when you first bought the Samsung Galaxy Note 3 will inform you whether the battery needs changing or not.
Symptoms I experienced with my old battery:
1. Great reduction in battery life compared to when it was new
2. Battery charging symbol appeared in Notification Bar whilst battery level kept getting lower
3. Reboot after switching phone on sometimes (battery power unable to meet the high demands of tthe entire system loading up).
I also had some root applications which started at boot fail & say they needed root until I changed the battery. I suspect other parts of the system and applications will also fail if the old battery had been left to degrade further than it already had.
Greetings
