Background

• When the original iPhone was introduced in 2007, one of the biggest criticisms of the device was its battery life compared with other mobile devices. The battery cannot be removed and replaced by the device’s owner, and must be taken to an Apple store to be replaced. However, according to Apple’s website, the lithium-ion batteries used in the iPhone offer the advantage of being able to recharge when it’s most convenient, rather than needing a full charge or discharge cycle needed to keep a nickel-based battery operating at its best.
  
  

Charge Cycles

• A significant confusion was among many iPhone owners as to what a charge “cycle” represents, according to a July 2007 "MacWorld" article. A cycle means a full charge and discharge cycle, meaning the battery has been fully drained and charged to full capacity. If an iPhone owner uses 20 percent of the device’s battery, then charges it up to 100 percent, and this does not represent a complete charge cycle, only a partial cycle, according to "MacWorld."
  
  

Considerations

• The number of charge cycles an iPhone battery can reach is dependent on the battery being properly maintained, according to the Apple website. A battery can start to degrade sooner than 400 cycles if there has been damage to the battery. After 400 charge cycles, the iPhone battery is designed to retain 80 percent of its original capacity, and will continue to lose capacity over time, according to Apple. According to a March 2010 article by CIO magazine, an iPhone permanently 30 seconds to one minute of battery capacity every time it is charged.
  
  

Battery Care Tips

• IPhone owners can take several approaches to extend the life of their iPhone battery. One of these is to use ther iPhone regularly, according to Apple, which keeps the electrons within the battery moving. iPhone owners should make sure they go through at least one complete charge cycle per month, which means charging the battery to 100 percent, then completely draining it. In addition, a battery’s capacity can be degraded if the iPhone is exposed to excess heat, so owners should take care that when their iPhone is in a carrying case, it is not overheating. According to the CIO article, iPhone owners should avoid using their iPhone in extreme temperatures, including below 40 degrees Fahrenheit or above 95 degrees. In addition, users can disable features that consume large amounts of power when not needed, such as Wi-Fi, notifications and location services, according to CIO.