Gai would like to know how long a tank of chemical last when spraying

How do you charge it. Because the red button is not working and i don’t know how to check the battery talk more of recharging it.

How can I get one and much does it cost

How do you mix your solution? The other one says water and the other is drug. In the water i just put water right? And in the drug i put the diesel and the insecticides. Is that correct?