I recently purchased(from ebay, cheaply...) a couple of extended batteries(i.e. 1800mh rather than the standard 1500mh)which give marginally better battery life. My question is, are Mugen batteries effective? They aren't cheap, but I really need to extend the single charge life of my phone. I am quite a heavy user of my phone, use wifi a lot as well as a number of apps, plus it's rooted/custom kernel/overclocked, so subsequently my standard battery can last between 5-15 hours. The 1800mh batteries last maybe 1-3 hours longer but, as with the x10, battery life is unpredictable so if I can find a truly extended battery then I'd be happy. Any feedback?