Knapsack sprayer

A knapsack sprayer, comprising:

• a liquid reservoir configured to store liquid;
• a nozzle configured to spray the liquid;
• an operating device connected to the liquid reservoir and the nozzle and configured to be held by a user to control a spraying direction of the nozzle;
• a power unit powered by a battery pack and comprising an electric motor and a pump;
• a valve in fluid communication with the pump, wherein the valve has a closed state in which the liquid is prevented from passing through the valve and an open state in which the liquid is allowed to pass through the valve;
• and
• an operating member configured to be operated by the user to switch from a state in which the electric motor is prohibited from starting to a state in which the electric motor is allowed to start and then be operated by the user to switch the valve from the closed state to the open state.

A knapsack sprayer, comprising:

• a liquid reservoir configured to store liquid;
• a nozzle configured to spray the liquid;
• a power unit powered by a battery pack and comprising an electric motor and a pump, wherein the electric motor drives the pump to draw the liquid from the liquid reservoir to the nozzle for spraying;
• and
• an operating device connected to the liquid reservoir and the nozzle, configured to be held by a user to control a spraying direction of the nozzle, provided with a first operating member for allowing the electric motor to start or prohibiting the electric motor from starting, and configured to be operated by the user to adjust a flow rate of the nozzle.