Hello!!
I can be found in different sizes and in different equipment. I can be really hot sometimes if you use me for too long, and sometimes you hate me because I run out so fast, but besides that you couldn´t live without me!
I´m the battery of your phone, if I could be upgraded, I for sure would want to be forever lasting I would use different kind of sources (solar or kinetic) to be always charged and no getting hot!