I am trying to buy new attys for my Riva 510. Right now I have the regular 510 attys that came with the Riva 510 kit and my old Joye 510 kit. I don't know which atty to buy (silly me). So do I buy a High Voltage atty or a low voltage 510 battery. I want to keep the same performance of the attys that came with the kit or better BUT I don't want to kill my battery.