The theme of the battery, it is quite common in Ubuntu. In the section on Energy Manager, you have some options to maximize some of your battery life, such as lowering the rotation of the discs, to rest the screen when not in use, etc. For a discussion of the fans there is a default application in Ubuntu is used to control the issue of overclocking your PC, your PC probably is in Performance mode, using the processor cap (hence to be atop the fans). Put it on Ondemand mode or Conservative to use just enough of the processor. Also watch you do not have unnecessary processes at the beginning of the OS.