Probably the most important tips made available from users and experts alike is to regulate the temperature when the iPhone operates. The lithium-ion (Li-ion) battery from the iPhone functions very best in temperatures ranging from 32 to 95 degrees, or 0 to 35 degrees Celsius. At its extremities, the iPhone can still function between -4 and 113 degrees Fahrenheit (-20 to 45 degrees Celsius) but temperatures beyond these ranges will be detrimental to your iPhone battery. Put simply, leaving your iPhone in a freezer or in a hot car is probably not recommended. Keep it out of sunshine as well. - android
This next tip culled from forums and the like is not so clear-cut. There are some who claim that allowing the iPhone battery to totally discharge more than once monthly is not advisable, although some believe that no harm can come of it. What seems to have a consensus is that the iPhone battery should be fully discharged from a full a discharge monthly in order to reset the battery meter.
It is also beneficial to have an idea of your actual usage along with your battery life in order that you can more grasp your options. You can view your usage statistics inside the Settings Menu beneath the General Tab then Usage. You will notice Usage, which is the time that the iPhone was in active mode and that means you were on a call, watching a relevant video, listening to music, browsing the Internet, and so on. It will also show your Standby time, the total amount of time the iPhone may be running from its last full charge, whether in active mode or otherwise not. Usage divided by Standby time provides you with a percentage of the time you had been actively using your iPhone. The higher this percentage, the more often you will need to charge your iPhone, so plan accordingly.
Updating towards the latest official version of the software using iTunes may help you with taking care of the iPhone battery, but that is still up for grabs. Many folks complain that the update from three to 3.1 wreaked havoc on some applications. However, updates and patches should help improve the performance, so perhaps that last one was a bit of a fluke. At any rate, before updating your software, check out the forums to see what the feedback is from individuals who have already updated their software.
As well as, the old standby of employing on the applications you will need, turning off push, 3G and decreasing the brightness of the display etc are still part and parcel of maintaining your iPhone battery in good condition for a longer period. Just because you've heard it before does not imply it doesn't work.
Something totally new, though. Some users have seen that proximity to a cell tower (thus providing access to a strong signal) extends it life. This may be because network searching is taken to a minimum. So attempt to stay in areas with an above average signal. A last and final tip is to use your iPhone regularly, so that you massage the kinks out of the system and become knowledgeable about the peculiarities of your particular unit. All things considered, your phone can be a highly personal gadget, and should be treated as a result.- android