You can choose either VV or VW operation on the sigelei Zmax V3 by going to Menu Item #7 and selecting Power. The sigelei will now operate in VW mode. It will remember the last wattage setting you used during a battery change. In VV or Voltage mode at Menu Item #7 the last voltage setting entered will not be remembered during a battery change.How do you set the sigelei to auto voltage? I set mine manually, and it remembers the last voltage you setup when you change the battery.