I'm going to be selling my products at Comiccon in a few weeks, and I need my phone to be fully charged, or have the capacity to stay fully charged for up to 10 hours. I need to get one of the following for my phone, and would like some suggestions on the best products for the following: 1. Spare battery (which aren't sold anymore in any Montreal stores within reach of the metro) 2. Portable battery charger that doesn't require electricity to charge a phone (The charger itself should be and can be charged using electricity for multiple uses) 3. Battery extender? When my data plan is turned on, my battery doesn't last more than a few hours, so I'd like to get either a charger or a spare battery. What brands are good for the samsung galaxy S2 X, where's the best place to buy it (ebay.ca or amazon.ca - I'm in Canada) ??? What brands and locations should I avoid (buying directly from China??) Thanks!!