Introduction
This manual provides essential instructions for the safe operation, assembly, maintenance, and troubleshooting of your RYOBI ONE+ P2850 18V Cordless Multi-Purpose Mister. Please read this manual thoroughly before first use and retain it for future reference.
Important Safety Information
WARNING:
Chemical exposure risk. Always handle pressurized liquids with care. Use the mister in a well-ventilated area. Follow all manufacturer instructions for safe operation of the mister and any chemicals used. Wear appropriate personal protective equipment (PPE) such as gloves, eye protection, and respiratory protection as recommended by the chemical manufacturer.
Always ensure the battery is removed before performing any maintenance or cleaning procedures.
Package Contents
Verify that all items listed below are included in your package:
- RYOBI ONE+ P2805 18V Multi-Purpose Fogger (Mister Unit)
- RYOBI ONE+ P190 2Ah Lithium Battery
- RYOBI ONE+ P118B Battery Charger
- Operator’s Manuals (this document)

Setup
1. Charging the Battery
- Connect the RYOBI ONE+ P118B Battery Charger to a standard electrical outlet.
- Slide the P190 2Ah Lithium Battery onto the charger until it clicks into place.
- Allow the battery to charge completely. The indicator light on the charger will show the charging status. Refer to the charger's specific manual for detailed light indications.
- Once charged, remove the battery from the charger.

2. Installing the Battery
- Ensure the mister's power switch is in the OFF position.
- Align the charged battery with the battery port on the rear of the mister unit.
- Slide the battery into the port until it locks securely into place.
3. Filling the Chemical Tank
- Ensure the mister is turned off and the battery is removed.
- Unscrew the tank cap located on the top of the chemical tank.
- Carefully pour your desired treatment solution (fungicide, herbicide, insecticide, etc.) into the tank. Do not exceed the 0.5-gallon fill line.
- Securely replace the tank cap.
- Important: After each use, slightly loosen the tank cap to release any pressure buildup and prevent potential leaks.

Operating Instructions
1. Starting the Mister
- Ensure the battery is installed and the tank is filled.
- Hold the mister firmly by the handle.
- Press and hold the trigger to activate the mister. There may be a brief warm-up period before fogging begins.
2. Spraying Techniques
- Maintain a steady, even motion while spraying to ensure uniform coverage.
- The mister is designed to cover up to 1,000 square feet per minute.
- Atomized particles can travel up to 15 feet in height, allowing for treatment of elevated areas.
- For optimal fogging, keep the mister relatively level. Angling the unit too sharply up or down may cause it to spray liquid instead of fog, or stop spraying altogether.
- Avoid over-saturating areas.


3. Stopping the Mister
Release the trigger to stop the mister. If using certain chemical sprays, a slight "spitting" of liquid may occur when the trigger is released. Keeping the sprayer tip slightly elevated when stopping can help minimize this.
Maintenance
Regular maintenance ensures optimal performance and extends the life of your mister.
- Always remove the battery before cleaning or performing maintenance.
- Cleaning the Tank: After each use, empty any remaining solution from the tank. Rinse the tank thoroughly with water. If using sticky or oily solutions, a mild detergent may be necessary, followed by a thorough rinse.
- Cleaning the Nozzle: If the mist output becomes inconsistent, the nozzle may be partially clogged. Refer to the detailed diagram in the full operator's manual for instructions on how to safely clean or clear the nozzle.
- Battery Care: Store the battery in a cool, dry place away from direct sunlight. Do not store batteries in a discharged state for extended periods.
- Storage: Store the mister in a dry, protected area, out of reach of children. Ensure the tank is empty and clean before storage.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Mister does not turn on. | Battery not charged or not properly installed. | Ensure battery is fully charged and securely inserted. |
| Mister sprays liquid instead of fog. | Unit is angled too sharply; tank overfilled; solution too viscous. | Keep mister level during operation. Do not exceed max fill line. Ensure solution viscosity is similar to water. |
| Mister is leaking from the tank area. | Tank cap not tightened properly; pressure buildup; seal issue. | Ensure tank cap is securely tightened. Loosen cap slightly after each use to release pressure. Inspect tank seals for damage. |
| Inconsistent mist or no mist. | Nozzle clogged; low battery; empty tank. | Clean the nozzle. Charge the battery. Refill the tank. |
Specifications
| Feature | Detail |
|---|---|
| Model Number | P2850 |
| Power Source | 18V Lithium-Ion Battery |
| Tank Volume | 0.5 Gallons |
| Recommended Uses | Pest Control, Weed Control (with compatible solutions) |
| Item Weight | Approximately 8.7 Pounds (with battery) |
| Material | High Density Polyethylene (HDPE) or Polyethylene Terephthalate (PET) |
| Included Components | Mister Unit, 2Ah Lithium Battery, Battery Charger, Operator's Manual |
Warranty and Support
For warranty information, technical support, or to locate authorized service centers, please refer to the official RYOBI website or contact RYOBI customer service directly. Retain your proof of purchase for warranty claims.
Manufacturer: RYOBI Tools
UPC: 737669725639, 046396024275