Big batteries cost big bucks and require lots of maintanence. We've come a long ways in battery technology in the last couple of decades but it still has a long ways to go.
There are some technological hurdles, that when finally crossed, will usher in a wave of technology that changes our lives. One big one is greatly reducing the cost of moving people and equipment from the Earth's surface into space. A second one is producing huge amounts of power from a very small device. One example is to have a car engine that can fit in your palm. Another example is that we could build a plasma light saber but you would need a nuclear power plant strapped to your back. Once we're able to produce large amounts of energy in a small device we will change how people live their lives. Finally, the ability to store large amounts of energy in a small device, for a long period of time, will also change our world.
I now return you to your regularly scheduled thread.