As with any smartphone, the iPhone has its strengths and it has its weaknesses, and the device’s battery is definitely one of the latter. The iPhone’s notoriously small battery is one of Samsung’s favorite targets when making fun of the iPhone, and the iPhone 6S definitely isn’t an exception, quite the contrary actually. If you pay attention to Apple’s official promo for the iPhone 6S, you’ll notice that it says the device has a 1715 mAh battery, which is actually SMALLER than the battery on its predecessor.