well i went from the protege at near 3.7 volts to the protege at near 5 volts to the BB at near 5volts at 2 amps. what i can say is that my attys love the 5v 2a better then the 5v 1.5 a from my battery pack. also the juice and wetness of the atty play into the life span. high volts is for dripping plan and simple the higher the volts the wetter you need to keep the wire. any other questions i will be glad to answer via PM.