Why do phone batteries last a short time?

10/21/16

“Well, why do they?”
Batteries are one of the most indispensable drivers of modern civilization. And smartphones are of the chief applications of this technology. However, how is it that something so pivotal to society’s function wear out it’s sole power source so rapidly? Well, let’s think about it like an Engineer would. We know that batteries are powered by releasing stored chemical energy through reactions. However, batteries have a low energy density, meaning that a large battery will hold a relatively small amount of energy compared to it’s size. And since phones need to be smaller for practical use, the battery has to be small as well, and since the only other way to increase battery capacity is to increase the efficiency (which would increase costs prohibitively), smartphone users are stuck with low battery lifetimes!