[revaaron]

I have 2 3500mah batteries and they last about 1-2hrs longer than the original.

and I read this thread again, it seems that Coz turns off everything on this phone that makes this phone worth having. If you want to really increase your battery life, just turn the phone off and leave it in your pocket. You will probably get a couple weeks out of it just turning it on for a couple minutes a day.