As the number of big smartphones with big batteries grows in Asia, Samsung has generally been reluctant to follow the trend with its popular Note series. While the Note9 features a host of changes, I think the enlarged battery is easily the most significant, and the one that will set it apart from rivals. At 4000mAh, this new Note has a full 20% more battery capacity than its predecessor. And while that may not sound crazy, it amounts to 700mAh, which should easily make the Note9 an all-day-and-then-some device for even heavy users. That's a big upgrade, and one that smartphone enthusiasts have been asking manufacturers to provide in their high-end handsets for years.