One of the main complaints of the modern smartphone is that their battery life seems to have just decreased over time. Yet that is not entirely true – these days phones have so many antennas and sensors, that the phone is almost constantly draining power from an ever increasing battery size. Manufacturers have had a tough time – on the one hand phones are becoming ever slimmer and lighter, with more power draining features, yet the battery life has to improve as well with every generation. So battery technology has definitely improved, our demands are just greater than ever.

If you use your iPhone (regardless which model) intensively, you are looking at around a day long battery life, but it can quickly run out within a workday if you are particularly busy with your phone. But there are a few things you can do to make the battery last that little bit longer.

The main idea behind these tips is that you so not have to impede the functionality of the iPhone. Its a great device, and it would be a shame to go and switch almost all functionality. But then what is the point of having a decent phone?

These are the settings I use which do not limit the functionality of the phone:

1) Wifi reception:

If you are not using Wifi at home or work, switch it off. But, if you are using Wifi a lot, you will save battery power if the phone does not have to constantly check for new networks.

Go to: Settings -> Wifi Networks -> Then switch off “Ask to Join Networks”.

Also, using Wifi does use less battery power than 3G. So if you have the ability to connect to wifi networks at home or work, use them. Also, while we are talking about radios – if you do not use Bluetooth anywhere, keep it switched off as well…

2) Push Email and Push Notifications:

This seems to have a very big effect on battery life, especially if you have multiple email accounts, and many apps.

You have to ask yourself – do you really need to have a constant connection to your email? Do you have to get that email or meeting request the moment it is sent? Or is once every 30 minutes enough to keep in contact? Obviously if you are dealing with on the minute deals (or whatever), keep Push Email on. But here is how to deactivate it:

Go to: Settings -> Mail, Contacts and Calendar -> Fetch New Data -> And change the “Push” switch to Off.

Then go and set at which interval you want the phone to check for new mail and calendar entries. I personally set it to 30 minutes, but its your own preference. If you only want the phone to check for Mail only if you open the app, select “Manually”.

One pointer here: If you are running an older version of iOS, this might disable Find My iPhone if you switch off Push. My recommendation is to update to the latest version of iOS available. On the latest iOS, Find My iPhone is not affected.

Push notification services are great, but are not needed for every single app you have. For example – getting a notification if your share portfolio falls 10% is a lot more handy than Angry Birds asking you why you havent played in a few days. Push Notifications require the phone to make multiple connections every hour in order to not miss out on messages, regardless how important they might be. Best idea – control those apps. Here is how:

Go to Settings -> Notifications then go into every app where you dont need notifications:

For example: Go into one your games, and then go ahead and switch off all notifications for that app:

You can also be very choosey – e.g. you might not need twitter replies to appear on your phone’s Lock Screen (so the screen does not need to light up with every twitter reply), but you do want a banner ad to appear when you unlock the phone:

It does take some time if you use a lot of apps, but the battery life gains will be worth it.

3) Screen Brightness and Sleep

This one is pretty obvious. That screen on the iPhone does take some juice to stay bright. So go try a slightly lower setting, and see if you are able to live with it. Most iPhones ship with the screen at half brightness, but you might just find that using a slightly lower setting might work fine, while saving your battery in the process. From iOS6, Apple has made the Auto-Brightness changes a lot more aggressive (and quicker to react), so I recommend keeping it on.

Go to: Settings -> Brightness. Slide the control to the left to decrease the brightness. Also ensure “Auto Brightness” is switched on.

Also, you should set your Auto Lock time to 1 minute. Do you really need the screen to stay on for 2+ minutes if you are not using the phone?

Go to: Settings -> General -> Auto Lock. Choose 1 Minute.

Sleep: OK, I only wanted to give tips that do not impede on your usage of the iPhone – and this is the only one that takes some getting used. Luckily many of us do this already, but many do not. Its pretty easy. When you are done using the phone, just put the phone into sleep mode, by clicking the button on the top right of the device. This will prevent the screen just staying on, and many apps will actually go into a sleep state, which saves power. This tip goes for any modern touchscreen phone, not only the iPhone.

4) Location Services

OK, now many articles tell you to just switch this off. But that is one too far in my opinion – after all, many of the best uses of any iDevice relies on the GPS sensor inside. Problem is these days just about any app you fire up quickly uses location services to check where you are, and if you many apps in a day, that is quite a lot of little checks using triangulation and GPS coordinates, all taking battery power. Now think about it – if you open up Facebook, Twitter, and News24 multiple times a day, do you really need the app to check your location every time? Not really. Time to control all those apps.

Here is how you do it:

Go to: Settings -> Privacy  -> Location Services -> keep the top switch on.

You will see all the apps that can use location services below that. You can go and disable all the apps that you do not want to use location services in (like do you need to have Angry Birds check where you are?). iOS also gives you some pointers – all the apps that have used location services in the past 24 hours will have to little greylocation service icon next to it. Apps currently using the GPS will have a coloured GPS arrow next to it. Obviously navigation apps should have location services switched on, and you might want to have the location stored of every image you take, so keep Camera on.

5) Learn how to use Multitasking, and How to Kill Apps

Multitasking is one of those features that Apple only added later to iPhone in iOS 4, somewhat begrudgingly I guess (due to many requests over time by power users). But now that it is available, many people are not even aware of it. They just keep using the phone they always have, without ever opening the multitasking dock.

Apple’s implementation of multitasking is pretty smart in that it freezes most apps when not in use, but then only allows certain services to run in the background, for example the GPS sensor for a navigation app. This results in much better battery life than most other smartphones (I’m looking at you Android), but it still helps to learn how to kill apps if necessary. (This is only relevant to iPhone 3GS and iPhone 4)

Double Click the Home Button – you will see that a dock pops up with the last opened apps.

Hold any these for about a second, until it start wiggling. A small red minus symbol appears above them. This is used to kill apps.

This last tip is only needed now and again – for example, I only use it after I used the Co Pilot navigation app on my phone (see our review here). Otherwise I tend to leave background apps going, but you might discover some app that still uses some or other allowed service. If you are unsure, go ahead and kill all background apps. Do not worry, it will not delete the app.

You will see that other lists all over the web go to various extremes to save battery power – like switching off Notifications, turning off 3G, etc. Of course these help, but its things I cannot live without.

But by just using these 5 tips I have pushed my iPhone’s battery to more than a day. Your mileage might vary depending on how much you use it. As a bonus, all of these tips should work with iPad as well – but then again the iPad has much better battery life that you might not even have to bother…

Let us know if these tips work for you in the comments! Also, if you have any other tips, let us know?