High Capacity SmartPhone Battery will kill the power bank or external battery?

Nowadays the smartphone battery are become more and more powerful. i search it from the internet and know that a gionee phone with 5000mah battery becomes popular and innos release a phone with 6000mah. so i was really doubt that if the battery become more and more powerful. it will kill the power bank ? at least for me if i have a smartphone with 6000mah i will not or seldom use my easyacc power bank.

Acer Iconia Tab 8 higher capacity battery?

Hi everyone. I have owned this Acer tablet for about a month now. No complains whatsoever. Really good performer. Only major downside so far is the short battery life.
I have been trying to find a higher capacity battery for this tablet or a way to increase battery life. While typing this I have started wandering with the idea of rooting this device to see if there is any battery life improvements.
Well, in the meantime, it would be great to find a higher capacity battery somewhere around.
Thanks for any response.