I've been contemplating a mod for a while that would have two 14500s or 18350s in parallel. I would very much like to use an integrated USB charging circuit in the mod. I can't think of any reason that a charger board would have a problem with two batteries in parallel, but that doesn't mean a reason doesn't exist. I intend to use one of the ego/tornado fast chargers (420mA, I think) so that it won't take a week to recharge the batteries. Has anybody tried this?