What would be needed to vape 510 on the road several days at a time? I mean to keep charged. What kind of chargers, etc. Would iphone usb work, or any usb, or are these special usb's 4 e-cig batts? Also would a pcc be helpful for this and if so, how are those things charged up? Just trying 2 figure out what all to purchase with the 501. Thanks for any advice!