Has your iPhone battery life decreased with OS4?

Well, the chances are it has if you do not know what we are about to tell you! Search the web and you will find a lot of people wondering why their iPhone battery life has suddenly started worsening. They nearly all have one thing in common - they have installed the iPhone OS4 update.

Luckily, the problem is easy to solve but you need to know why it is happening too. Your iPhone can now multi-task with OS4. That is, it leaves other applications running instead of shutting them down like previously. It is not true multi-tasking, but it does use significantly more battery power if you leave a lot of apps open without realising what you have done.

How to fix it

Press the home button twice (the button on the bottom front of your iPhone). The top of the screen will fade out and you should see a section at the bottom like this (the icons will differ, depending on what apps you have running at the time):

Those are all the applications that are still open and using battery power! Now, press and hold one of the icons until they start wobbling in the same way they do if you want to delete an app from your iPhone. They will then look like this:

Finally, tap the little minus icon in the top left of each application - and it shuts down. You will now find you end up with a blank bottom bar like this:

Hey presto, you will find your battery lasts as long as it did before you upgraded! Just remember to close down apps properly whenever you have used them in future.