We decided to put that claim to the test, and chucked in Apple's first ever phablet – the iPhone 6 Plus – to the mix as well so you can see how the three generations of 5.5-inch iPhones compare.
In our simple test we cranked screen brightness up to maximum levels and connected all three to the same Wi-Fi network. We then ran a website script on the handsets for two hours, followed by a Real Racing 3 gaming session until they died.
Which phone came out on top? Well, let's just say the iPhone 7 Plus has a bigger battery for a reason...
Watch our full battery test video below
- Read our iPhone 7 Plus review