iPhone Battery Woes

Lifespan of the iPhone Battery
  
Well, specifically, I am referring to the lithium-polymer battery type used by Apple for the iPhone device.

A lot of users of the 3GS notice that they need to charge their device an average of once a day. Heavy users, and this I mean users who make a lot of calls, and do ACTUAL work with it may even need to charge their device more than once a day, and usually end up buying an external battery add-on like the much debated Mophie-Air, or Energizer Battery Add-ons. 

Apple had mentioned that the 3GS model will have a significant improvement on its battery life over the previous 3G incarnations. 
 
We are told that it (iPhone 3GS battery) can last for about 400 cycles while retaining up to 80% of its original capacity. That leaves some folks guessing 'What is one single cycle?", "Does that mean I have to use the device till it is nearly discharged (near 0% charge) before I can charge it in order to maintain optimal battery lifespan and power capacity?"

Well, simply put, one single charge cycle means charging the device from 0% (nill power capacity) to 100% (full capacity). If you decide to begin charging your phone when it has dropped to just 90% (of full charge capacity) till it reaches 100% (full capacity). That equates to charging it at one tenth (1/10) of one cycle. Which in turn translates into doing this 4000 times to mean 400 cycles before you start to experience a drop in the iPhone battery's standby, call and usage periods before requiring charging again.

According to Apple, the "iPhone 3GS offers up to 5 hours of talk time on 3G, 12 hours of talk time on 2G, 5 hours of Internet use on 3G, 9 hours of Internet use on Wi-Fi, 10 hours of video playback, or 30 hours of audio playback on a full charge at original capacity. In addition, iPhone features up to 300 hours of standby time." (http://www.apple.com/batteries/iphone.html)

There are a plethora of apps available via App Store which indicates the current charge capacity of the device and in turn will also translate that into how much talk time, game usage time, web-surfing time and more. One such app is "Battery LED Free", which does all this and also indicates usage for 3G and 2G usage.

It might be a good idea to occasionally discharge the iPhone completely before charging it again as recommended by Apple. And once again, there are detractors of this. Read more about lithium-polymer batteries on this wikipedia page and make your own decision.

http://en.wikipedia.org/wiki/Lithium-ion_polymer_battery