When it comes to the new iPhone 6S, according to Apple, "the only thing that's changed is everything".
You know what hasn't changed, though? Battery life. Sure, the actual battery has been made physically smaller than the iPhone 6, yet somehow it lasts just as long.
That said, as much as we love our iPhones, they're just not the longest-lasting mobiles on the block and sometimes struggle to make it through a heavy day of usage on a single charge unless you've gone Plus-size. That dreaded 'battery low' alert can pop up at the most inopportune of moments, but not if you make 'eking out' your speciality.
1. Do some detective work
If your iPhone consistently struggles to make it through the day, you need to take remedial action. The first thing to do is identify what the problem is. Here's a clue: there'll almost certainly be an app involved.
To find out precisely which app is gobbling all the power, head into the Settings menu and select Battery. Scroll down to the Battery Usage section, and it'll give you the lowdown on the most power-hungry apps over the past 24 hours and even the past week. Yeah, it's Facebook, isn't it?
2. Restrict sneaky apps
Part of the problem with apps like Facebook and Twitter is that they keep on operating in the background, even when you're not directly using them. This saps a fair amount of power.
If you're not desperate to find out the minute your old high-school acquaintance has a Starbucks Frappuccino, consider switching this feature off by heading into Settings >> General >> Background App Refresh and disabling the feature for non-essential apps.
3. Turn off notifications
Do you find it stressful when your iPhone bombards you with notifications from every last installed app? Perhaps you don't, but your iPhone does. Pulling out those snippets of data and pushing them to your screen eats up precious battery percentage points.
Have a long hard think about which notifications you actually want or need. Then, go into the Notifications section in Settings and flick the Allow Notifications toggle to the off position. Your iPhone (and everyone around you) will thank you for it.
4. iOS 9's Low Power Mode
Have you downloaded iOS 9 to your iPhone yet? Perhaps you've got a shiny new iPhone 6S Plus that comes with it pre-installed (you lucky thing). Either way, there's a great new feature that can stretch out your battery life when things get hairy.
The next time your iPhone's battery life hits precarious levels (20%), or when you know you're going to need it to stay powered on for a protracted spell, head into the Battery menu in Settings and flip the Low Power Mode toggle on. This will turn off various power-sapping settings and features until you can get to a wall socket.
5. Turn off whizzy effects
One of the things Low Power Mode does to extend your iPhone's battery life is to reduce unnecessary animations. Believe it or not, iOS is full of them, and they all require additional processing power (particularly from the GPU) to execute. More processing power means more battery usage.
You can deactivate these effects manually in two ways. First, go into Settings >> General >> Accessibility, then turn the Reduce Motion option on. Second, Go into Wallpaper within Settings and ensure that you have a Still rather than a Dynamic wallpaper selected.
6. Drop the screen brightness
Unless it's a particularly sunny day, you probably don't need your iPhone's screen brightness to be cranked right up. There's a very good incentive to turn it down, too, as the display is the most power-hungry component of all.
You can drop your iPhone's screen brightness simply by pulling up Control Centre - swipe up from the very bottom of the screen - and shifting the top slider to the left. You should also head into Display & Brightness in Settings and turn Auto-Brightness off, as your iPhone does like sneaking the brightness up again when you're not looking. The cheeky scamp.
7. Turn off location services
There's one particular function of your iPhone that demands a fair amount of power relative to the amount of use it often gets. We're talking about location tracking, which harnesses your phone's GPS, Bluetooth, Wi-Fi, and mobile network connections to stay aware of where you are.
Unless you're using a navigation or fitness app, it's pretty inessential that your iPhone knows your location in this way. Disable the function by going into the Privacy section of the Settings menu and selecting Location Services. Here you can turn the iPhone's tracking function off altogether, and even set exceptions for key apps (like Google Maps, for example).
8. Speed up the auto-lock process
If you don't habitually reach for your iPhone's power/sleep button every time you finish using it for something, then you're relying on your phone's auto-lock system to power the screen down.
As we've already noted, screen-on time is where battery life takes the biggest hit, so it's a good idea to minimise it. Head into Settings >> General and select Auto-Lock, then drop it right down to 30 seconds. Your iPhone will now enter sleep mode of its own accord much quicker.
9. Engage in a little Email DIY
For many people, email simply isn't the instantaneous communication method it used to be. That job has been delegated to various chat and social networking services. If you think about it, then, you might not need your iPhone to pull in emails for you on a regular basis.
There's a good chance you can get away with just checking your emails manually whenever it occurs to you, which would save a good amount of battery power. Go into Settings >> Mail, Contacts, Calendars, then select Fetch New Data and turn Push off. Also, if you have additional accounts like Gmail or Outlook, switch them from Fetch to Manual.
10.Stop those bad vibrations
The iPhone 6S has a sophisticated new Taptic Engine that provides vibration-based feedback, but every iPhone has a vibration motor of some kind. These tiny mechanical motors sap precious power, often unnecessarily.
If you can get by on sound alone for things like ringtones and notifications, head into Settings >> General >> Accessibility, select Vibrations, and flick the toggle to the off position.
11. Use Wi-Fi wherever possible
As a general rule of thumb, surfing the web on your phone using a mobile network connection drains more power than when on a decent Wi-Fi connection.
This may not be the case if you have a strong 4G signal and the alternative is a weak public Wi-Fi hotspot, but generally the need to transmit data over large distances and constantly reestablish a connection saps your iPhone's battery quicker than Wi-Fi. 3G network connections, in particular, are infamously power-hungry.
12. Cut out the 3D games
Your iPhone is designed to use only enough processing power to complete the task at hand, and nothing prompts it to open the floodgates like a 3D game. In particular, such advanced applications tend to place the largest possible demands on the iPhone chip's GPU (graphics processing unit).
At full throttle this component drinks a lot of juice, which is why your iPhone can get uncomfortably hot during gameplay. As a result, playing a complex game can eat through a full iPhone charge in just a few short hours. Just play Threes instead.