Fix Electric Lawn Mower

Lawn Mowers
M
Marcus Chen
Small Engine Mechanic, ASE Certified
Electric lawn mower repair
Electric lawn mower repair

Electric lawn mowers have fewer parts than gas mowers but still need occasional repairs. This guide covers troubleshooting for both corded and battery-powered electric mowers.

Table of Contents

Electric Mower Types

Corded Electric

Pros:

  • Unlimited runtime
  • No battery to replace
  • Lighter weight
  • Lower cost

Cons:

  • Limited range (cord length)
  • Cord management hassle
  • Trip hazard

Battery Powered (Cordless)

Pros:

  • No cord to manage
  • Portable
  • Quiet operation
  • No emissions

Cons:

  • Limited runtime
  • Battery replacement cost
  • Heavier than corded

[NEED IMAGE: Corded vs cordless electric mower comparison]

Won’t Start Problems

Corded Mower Checklist

  1. Check outlet - Test with another device
  2. Check extension cord - Use outdoor-rated, proper gauge
  3. Check cord connections - Both ends secure
  4. Check safety key - Must be inserted
  5. Check safety bar - Must be held engaged
  6. Check thermal protection - May need cool-down

Cordless Mower Checklist

  1. Check battery charge - Fully charged?
  2. Check battery connection - Seated properly?
  3. Check safety key - Inserted correctly?
  4. Check safety bar - Engaged?
  5. Check battery contacts - Clean and undamaged?
  6. Try different battery - If available

[NEED IMAGE: Electric mower safety switch locations]

Safety Switch Troubleshooting

Electric mowers have multiple safety interlocks:

SwitchLocationFunction
Safety keyTop of mowerMaster enable
Bail barHandleMust hold to run
Grass bagRearSome require bag
Height lockWheelsMust be set

Testing switches: Most switches can be tested with a multimeter for continuity. Never bypass safety switches permanently.

Motor Issues

Motor Won’t Run

Possible causes:

  • Thermal overload tripped
  • Motor brushes worn (brushed motors)
  • Motor windings damaged
  • Control board failure

Diagnosis:

  1. Let mower cool 15-30 minutes
  2. Check for burning smell
  3. Listen for humming without spinning
  4. Check blade for obstruction

Motor Runs But Weak

Possible causes:

  • Low battery (cordless)
  • Voltage drop in cord (corded)
  • Worn motor brushes
  • Clogged deck restricting blade

Fixes:

  1. Use shorter/heavier gauge cord
  2. Charge battery fully
  3. Clean deck thoroughly
  4. Replace brushes if accessible

Motor Overheating

Causes:

  • Cutting too heavy/tall grass
  • Dull blade (motor works harder)
  • Blocked ventilation
  • Motor bearing failure

Prevention:

  • Cut grass more frequently
  • Keep blade sharp
  • Clear grass from motor housing
  • Don’t force through thick grass

Battery Problems

Battery Won’t Charge

Check order:

  1. Charger indicator lights
  2. Battery contacts (clean?)
  3. Different outlet
  4. Battery temperature (too hot/cold)
  5. Try different charger if available

[NEED IMAGE: Electric mower battery troubleshooting]

Battery Won’t Hold Charge

Causes:

  • Battery age (3-5 year lifespan)
  • Extreme temperature storage
  • Deep discharge damage
  • Cell failure

Solutions:

  1. Full discharge/charge cycle
  2. Store at room temperature
  3. Replace battery if old

Battery Life Tips

  • Store partially charged (40-60%)
  • Avoid extreme temperatures
  • Don’t store fully depleted
  • Charge before each use
  • Use correct charger only

Battery Replacement Costs

BrandBattery SizeCost
EGO56V 5.0Ah$200-250
Greenworks40V 4.0Ah$100-150
Ryobi40V 6.0Ah$150-200
DeWalt20V 5.0Ah$80-120

Blade and Deck Issues

Blade Replacement

Electric mower blades work the same as gas mowers.

When to replace:

  • Visible nicks or damage
  • Won’t hold sharp edge
  • Bent (causes vibration)
  • Excessive wear

Replacement steps:

  1. Remove battery or unplug
  2. Tip mower (motor side up)
  3. Block blade from turning
  4. Remove blade bolt (usually right-hand thread)
  5. Install new blade
  6. Torque to spec (typically 25-35 ft-lbs)

Deck Cleaning

Electric mowers need regular deck cleaning like gas mowers.

Process:

  1. Remove power source
  2. Tip mower on side
  3. Scrape buildup with plastic tool
  4. Spray with deck cleaner
  5. Rinse if model allows
  6. Dry before storing

Blade Drive Issues

Belt-driven models:

  • Check belt condition
  • Verify proper tension
  • Look for debris in pulley

Direct-drive models:

  • Check blade adapter
  • Verify motor shaft not bent
  • Check for debris between blade and deck

When to Repair vs Replace

Repair If

  • Battery is only issue (replaceable)
  • Simple switch or cord problem
  • Blade/deck mechanical issue
  • Mower is less than 3 years old

Replace If

  • Motor failure on older unit
  • Control board failure (often costly)
  • Multiple issues simultaneously
  • Repair exceeds 50% of new price

Cost Comparison

RepairTypical Cost
Switch replacement$20-50
Blade replacement$25-50
Battery replacement$100-250
Motor brushes$30-60
Motor replacement$150-300
Control board$100-200

Maintenance for Electric Mowers

After Each Use

  • Clear grass from deck
  • Wipe down exterior
  • Store indoors or covered

Monthly

  • Check blade condition
  • Clean battery contacts
  • Inspect cord (corded models)
  • Check wheel operation

Annually

  • Sharpen or replace blade
  • Deep clean deck
  • Check all fasteners
  • Test safety switches

Summary

Electric mower repairs are often simpler than gas mowers since there’s no fuel system or carburetor. Most problems are electrical - switches, connections or batteries. Keep blades sharp and decks clean for best performance. Battery replacement is the biggest maintenance cost for cordless models.