Varrox Eddy is the first oxalic acid evaporator with included battery. No more towing of power generators or heavy car batteries. Varrox Eddy is lightweight, handy, and weighs less than 1.3 lbs including the battery. A single keypress on the device is enough to start the treatment. With a fully charged battery, you can treat up to 15 hives! The full battery charging time is a maximum of 4 hours. The Eddy requires an opening of at least .6 of an inch high and 3.54 inches wide. Well within most hive openings.