DeWalt DCMWSP550N Lawn Mower Manual

The DeWalt DCMWSP550N is a 20-inch cordless electric lawn mower powered by two 20V MAX* or 60V MAX FLEXVOLT® batteries (sold separately), featuring a brushless motor for extended runtime, a 3-in-1 capability (mulch, bag, side discharge), 7-position single-lever height adjustment (1.5-4 inches), foldable handles for compact storage, and a weather-resistant construction. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Assembly & Setup 3. First-Time Operation 4. Specifications 5. Controls and Settings 6. Battery & Charging 7. Mowing Operations 8. Maintenance & Storage 10. Safety Information 11. Warranty & Support 12. Troubleshooting

Features at a Glance

Key components: Steel deck, foldable handle with controls, battery ports, height adjustment lever, rear collection bag, mulch plug, and safety key.

Feature	Description
Power Source	Dual-port for two 20V MAX* or 60V MAX FLEXVOLT® batteries (not included)
Deck Size	20-inch steel cutting deck
Motor	Brushless motor for efficiency and longer runtime
Cutting Modes	3-in-1: Mulch, Bag, Side Discharge
Height Adjustment	Single-lever, 7 positions (1.5" to 4")
Handle	Foldable for compact storage
Safety Key	Removable key to prevent accidental start
Start System	Push-button electric start
Wheels	8-inch rear, 7-inch front wheels
Weight	Approx. 56 lbs (without batteries)

Assembly & Setup

Unpack and inspect all parts. Assemble on a flat, stable surface.

Attach the handle: Align handle brackets with deck mounts, secure with provided bolts and wrench.
Install the wheels: Slide axles through deck brackets, secure wheels with washers and push nuts.
Attach the grass bag: Hook bag frame onto rear deck mounts, ensure bag is securely fastened.
Insert the mulch plug (if mulching): Place plug into rear discharge chute opening.
Install batteries: Insert two fully charged 20V MAX* or 60V MAX FLEXVOLT® batteries into the ports.

WARNING! Ensure mower is turned off and safety key is removed during assembly. Tighten all fasteners securely.

First-Time Operation

Before first use, fully charge batteries and perform a safety check.

Insert safety key: Push the safety key fully into the slot on the control panel.
Adjust cutting height: Move the single lever to desired setting (start at highest position for first mow).
Select mode: Ensure mulch plug is installed for mulching, bag attached for collection, or chute open for side discharge.
Start mower: Press and hold the safety lever on the handle, then press the start button.
Mow: Walk at a steady pace, overlapping passes slightly for even cut.

CAUTION! Clear mowing area of debris, stones, and toys before starting. Do not mow wet grass.

Specifications

Model: DCMWSP550N
Cutting Width: 20 inches
Cutting Height Range: 1.5 - 4 inches (7 positions)
Power: Brushless motor, dual battery system
Battery Compatibility: DeWalt 20V MAX* and 60V MAX FLEXVOLT®
Deck Material: Steel
Collection Bag Capacity: 1.9 bushels
Wheels: 8" rear, 7" front
Weight (without batteries): 56 lbs
Warranty: 3-year limited warranty

Controls and Settings

Main controls located on the handle. Handle Panel: START button, SAFETY LEVER, HEIGHT ADJUSTMENT LEVER.

Operation: Press and hold safety lever to activate handle, then press START button. Release safety lever to stop blade (motor may continue running briefly).

Height Adjustment: Single lever controls all four wheels simultaneously. Move lever forward/backward through 7 detents. Lower Settings (1-3): For shorter grass. Higher Settings (4-7): For taller grass or uneven terrain.

Battery & Charging

Uses two DeWalt 20V MAX* or 60V MAX FLEXVOLT® batteries (sold separately).

Charging: Use only DeWalt chargers (DCB107, DCB112, etc.). Insert battery into charger; LED indicates status.
Installation: Insert batteries into ports until they click. Ensure polarity is correct.
Runtime: Varies based on grass condition, height, and battery capacity. Typically 30-60 minutes per charge.
Storage: Store batteries in cool, dry place. Charge fully before long-term storage.

Tip: Use two identical batteries for balanced performance. Do not mix old and new batteries.

Mowing Operations

Supports three cutting modes: Mulching, Bagging, Side Discharge.

Mulching: Install mulch plug. Cuts clippings finely and returns them to lawn as fertilizer.
Bagging: Attach collection bag. Collects clippings for disposal.
Side Discharge: Remove mulch plug and bag. Discharges clippings to the side (right).
Height Adjustment: Change setting based on grass type and season.
Overlap: Overlap each pass by 2-3 inches for even cutting.
Slopes: Mow across slopes, not up and down, for stability.
Clearing Clogs: Turn off mower, remove safety key, and tilt mower (with air filter side up) to clear debris.

WARNING! Always turn off mower and remove safety key before clearing blockages or performing maintenance.

Maintenance & Storage

Regular maintenance ensures optimal performance and longevity.

After each use: Clean underside of deck, remove grass clippings.
Blade Care: Periodically inspect blade for damage or dullness. Sharpen or replace as needed.
Wheel Check: Ensure wheels rotate freely and axles are secure.
Battery Contacts: Keep clean and dry.
Off-Season Storage: Clean thoroughly, remove batteries, store in dry location. Consider applying a light coat of oil to the blade.

CAUTION! Disconnect batteries before performing any maintenance. Never use water or pressure washer to clean mower.

Safety Information

Read all instructions before use. Always wear safety glasses, long pants, and sturdy shoes.

Keep hands and feet away from moving parts.
Do not operate on steep slopes (greater than 15 degrees).
Never leave mower unattended with batteries inserted.
Keep children and pets away from mowing area.
Use only DeWalt recommended batteries and chargers.
Do not mow in rain or wet conditions.

DANGER! The blade rotates at high speed. Always ensure mower is completely off and blade has stopped before crossing gravel drives, roads, or approaching bystanders.

Warranty & Support

DeWalt DCMWSP550N is covered by a 3-year limited warranty, 90-day money-back guarantee, and 1-year free service contract. Warranty covers defects in materials and workmanship under normal use. Batteries and chargers have separate warranties. For support, visit www.dewalt.com or contact DeWalt Customer Service at 1-800-4-DeWalt (1-800-433-9258). Register your product online for faster service.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Mower won't start	Safety key not inserted, dead batteries, safety lever not engaged	Insert safety key fully; charge or replace batteries; ensure safety lever is pressed firmly.
Poor cutting performance	Dull blade, low battery, cutting height too low	Sharpen or replace blade; charge batteries; raise cutting height.
Uneven cut	Uneven tire pressure, worn blade, deck clogged	Check wheels for debris; inspect and balance blade; clean underside of deck.
Excessive vibration	Damaged or unbalanced blade, loose parts	Stop mower immediately. Inspect blade for damage and tighten all bolts/nuts.
Battery not charging	Faulty charger, dirty contacts, battery temperature extreme	Try different charger; clean battery terminals; allow battery to reach room temperature.
Grass not discharging (bagging/mulching)	Wet grass, deck clogged, improper mode setup	Mow when grass is dry; clean deck; ensure correct plug/bag is installed.

Reset: Remove batteries and safety key for 60 seconds to reset electronic controls.

Service: For repairs, use an authorized DeWalt service center. Do not attempt to disassemble motor or controller.