As technology improves, people expect their cell phone to increase its functionality. However, an increase in performance also means faster processors and more advanced calculations, which generates higher heat and requires a larger amount of power. As a result, battery technology has to catch up to the increase in processor speed. However, news in the media indicate lots of users unsatisfied with their smartphone battery life. This paper aims to discuss various aspects of smartphone battery life.
One of the current limiting issues is that smartphones employ lithium-ion batteries. These batteries are popular because they have high energy densities. However, in the current state-of-the-art technology, scientists are unable to pack even more energy in such a small amount of space.  Furthermore, most of the latest, newest, and "coolest" features drain more energy than the older one. In one study, the researchers showed that even for the simplest SMS messaging and calling, sending through 3G is more energy consuming than using GSM. 
On the other hand, a lot of current practices in technology has been limiting battery life. For example, a lot of the vulnerabilities in cellular networks, mobile devices, and the data interaction can be captured and disrupted by virus, which wuickly drains the power of the mobile battery. Furthermore, studies have shown that when a phone installs Anti-virus and firewall, the power consumption increases by up to 40% depending on what state it is in.  Other studies have shown that mobile devices may be the next frontier for hackers' attacks. As more and more people put personal data on their phone as well as use their mobile device to manage financial transactions, there is a growing incentive to perform a cyber attack via mobile.  Although these viruses are primarily aimed at financial gains, many of these malicious attacks can also paralyze the phone by draining the battery, making it extremely difficult for the user to recover.
Current research has already been done to aim at solving the proposed problems. For the first problem, there has been research done to attempt to use renewable energy sources our electronic devices, including the mobile phone.  The study showed that although the current market in the consumer electronics battery space is not well-suited for solar cells, there is still potential for solar cells to be incorporated in consumer electronics devices.
Although mobile virus is still a relatively new concept, the consequences of them are huge and real. There has already been many attacks through the mobile space. While there has been companies aimed at creating anti-malware and anti-virus software for mobile phones, there has not been any large-scale research or development done in this area. It remains to be seen how the development goes, especially since most users are currently not aware of such software. In the future, once users accept antivirus software as a part of the phone just like in desktops and laptops, there may be a higher demand that drives people to put in more resources on protecting mobile phones from malicious attacks. Since anti-virus and protection software increases power consumption, there has been a call-to-action for "Green Security", to create anti-virus software that also minimizes the extra power consumption of the mobile device. 
© Kenny Kao. The author grants permission to copy, distribute, and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 G. P. Perrucci, et al., "On the Impact of 2G and 3G Network Usage for Mobile Phones' Battery Life," European Wireless Conference, EW 2009, 255 (2009).
 L. Caviglione and A. Merlo, "The Energy Impact of Security Mechanisms in Modern Mobile Devices," Network Security 2012, No. 2, 11 (2012).
 N. Leavitt, "Mobile Phones: The Next Frontier for Hackers," Computer 38, No. 4, 20 (2005).
 S. Lizin et al., "The Future of Organic Photovotaic Solar Cells as a Direct power Source for Consumer Electronics." Solar Energy Materials and Solar Cells 103, 1 (2012).