There are a few different options for extended battery cases. As far as how long will they last; there's too many variable for anyone to really answer that. Signal, Settings, usage, apps, connections are all things that can impact the battery and for each person they are typically different. Check the TiPB store they have a few options for extended batteries.
Originally Posted by ariellemerperle
Regarding Juice Defender - I'm not sure. I've looked at if for my Android devices but I don't like the idea or turning things off. I'd rather just use my phone and keep a charger handy.