Stihl SG20 Backpack Sprayer Manual

The Stihl SG20 Backpack Sprayer is a professional-grade, battery-powered sprayer designed for efficient application of liquids in gardening, landscaping, and agricultural tasks. It features a 5-gallon (20-liter) tank, variable flow rate control, ergonomic harness, chemical-resistant components, and a long-lasting lithium-ion battery system. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 5-gallon polyethylene tank, adjustable harness, variable-speed pump, telescopic wand with adjustable nozzle, lithium-ion battery, charger, and chemical-resistant hose/fittings.

Assembly & Preparation

Unpack all components and inspect for damage. Assemble on a clean, flat surface.

1. Attach harness: Slide harness straps through tank backplate slots and secure.
2. Install battery: Insert compatible Stihl AP battery into battery compartment until it clicks.
3. Connect hose: Attach hose to pump outlet and wand inlet, hand-tighten fittings.
4. Install wand/nozzle: Screw telescopic wand onto hose end, attach adjustable nozzle.
5. Prime pump: Fill tank with clean water, turn on briefly to prime system.

WARNING! Wear appropriate PPE (gloves, goggles, long sleeves) when handling chemicals. Do not use with flammable liquids.

First-Time Setup

Before first use, calibrate sprayer and familiarize yourself with controls.

1. Charge battery fully using Stihl AL charger (green light indicates full charge).
2. Fill tank with clean water for test spray; never fill with chemicals until ready to use.
3. Adjust harness: Loosen/tighten straps for comfortable, balanced fit.
4. Test spray pattern: Turn dial on wand to adjust from jet stream to fine mist.
5. Check for leaks: Run sprayer for 1-2 minutes, inspect all connections.

CAUTION! Always perform test spray with water in a safe area away from plants, animals, and people.

Specifications

• Tank Material: High-density polyethylene (HDPE), chemical-resistant.
• Battery Runtime: Up to 2 hours continuous use (varies by battery capacity and flow rate).
• Flow Rate: Adjustable from 0.1 to 1.3 gallons per minute (0.4-5 L/min).
• Spray Distance: Up to 20 feet (6 meters) with jet setting.
• Operating Temp: 40°F to 104°F (5°C to 40°C).
• Charging Time: Approx. 30-60 minutes depending on battery.
• Warranty: 2-year limited warranty (see separate warranty card).

Controls and Operation

Main controls located on wand handle and tank base.

Wand Handle: On/off trigger lock, flow rate dial, trigger. Tank Base: Battery compartment, pump housing, pressure relief valve.

Operation: Press trigger lock to unlock, squeeze trigger to spray. Adjust flow rate dial during operation for desired output. Use telescopic wand to extend reach. To stop, release trigger and engage lock.

Battery Indicator: LED on battery shows charge level (green=good, red=low).

Spraying Techniques

For effective, even coverage and reduced drift.

1. Maintain consistent walking speed and wand height.
2. Hold wand 12-18 inches from target surface.
3. Overlap spray patterns by 30-50% for uniform coverage.
4. Use fine mist for foliage, jet stream for hard surfaces or distant targets.
5. Avoid spraying in windy conditions (>10 mph).

Tip: Practice spraying technique with water on pavement before chemical application.

Maintenance & Cleaning

Clean after EVERY use, especially when using chemicals.

1. Empty tank completely.
2. Rinse tank: Fill 1/4 with clean water, agitate, and spray through system.
3. Repeat rinse 2-3 times until water runs clear.
4. Clean nozzle: Remove nozzle, soak in water, use soft brush to remove debris.
5. Store with tank cap off to allow air circulation.

WARNING! Never mix different chemicals in tank. Always follow chemical manufacturer's safety and disposal instructions.

Battery & Charging

Use only Stihl AP series batteries and AL series chargers.

• Charge battery at room temperature (60-80°F / 16-27°C).
• Store battery at 30-80% charge if not used for extended periods.
• Do not expose battery to water or temperatures above 140°F (60°C).
• Battery life: Typically 500+ charge cycles.

CAUTION! Do not use damaged batteries. Dispose of batteries according to local regulations.

Storage Guidelines

Store in cool, dry place away from direct sunlight and freezing temperatures.

1. Clean thoroughly as per Maintenance section.
2. Remove battery and store separately.
3. Drain all water from tank, hose, and pump.
4. Store with tank cap off and hose/wand detached if possible.
5. Keep away from children and pets.

CAUTION! Do not store with chemicals in tank. Never store in temperatures below 23°F (-5°C).

Safety Information

Read all instructions before use. Wear appropriate PPE: chemical-resistant gloves, goggles, long sleeves, pants, and closed-toe shoes. Work in well-ventilated areas. Do not eat, drink, or smoke while spraying. Wash hands thoroughly after use. Follow chemical manufacturer's instructions for mixing, application, and disposal. Keep sprayer away from open flames or sparks.

FIRST AID: If chemical contact occurs, rinse immediately with plenty of water for 15 minutes and seek medical attention. Have MSDS for chemicals available.

Troubleshooting

Service: For repairs, contact authorized Stihl servicing dealer. Do not attempt to repair pump or electrical components yourself.

Support: 1-800-467-8445; www.stihlusa.com