AppleInsider writes that Apple is researching new ways to increase battery life in its devices, specifically how to keep the battery the same size at the same time as increasing its energy capacity. This information has been obtained from a patent application filed by Apple and discovered by AppleInsider, which details using “multi-step constant-current constant-voltage (CC-CV) charging technique” to charge a battery. This technique would apparently enable the material that makes up the battery to be increased in “volumetric and gravimetric energy density” while the size of the battery, and its maximum charging time and minimum life cycle would stay the same, according to AppleInsider.
In the application, Apple also says that it wants to make battery cells smaller in order to use the space inside portable devices more efficiently, and that it would use the extra space to introduce new features or more battery capacity. It seems that the CC-CV method also has a downside though, as temperature can have an extreme affect on the battery’s cycle life, as can charging it when it is in a higher charged state (from 70 percent to 100 percent). The patent application proposes a solution to that problem though, of reducing the charge currents of a device when its battery is at a higher state of charge, or a colder temperature.
AppleInsider says that the patent, although only discovered this week, was actually filed with the U.S. Patent and Trademark Office back in August 2009.
Source: AppleInsider | Apple looking to increase battery life with dense lithium cells