Amazon offers HART 20-Volt 1/2 Gallon Fogger (1) 20-Volt 2.0Ah Lithium-Ion Battery for $39.00 (orig. $97.00) + Free Shipping. 

Product Description:
"The HART 20V Fogger is the perfect tool for your light-medium duty fogging needs! The HART 20V Fogger covers up to 10,000 sq. ft. per charge and is ideal for spraying insecticides, fungicides, and herbicides. This fogger sprays particles up to 15 ft. away for hard to reach areas. It has a portable, lightweight design and is equipped with a 1/2 gallon tank capacity for user convenience. The HART 20V Fogger and HART 20V Battery are covered by 3-year limited warranties. "

• Perfect tool for your light-medium duty fogging needs
• Covers up to 10,000 sq. ft. per charge and is ideal for spraying insecticides, fungicides, and herbicides
• It has a portable, lightweight design 
• Equipped with a 1/2 gallon tank capacity for user convenience