So I purchased a Gorilla Gadget's 3500 battery because it's supposed to take me through a few days of charge. I have not put it in my phone yet, nor have a I charged it up. What is the best way to condition the battery ? I cannot put it in the Evo and leave the Evo off for hours. Should I get an external charger ? Also, what cases are best for use with the 3500 battery ?