STIHL T5420 Manual

The STIHL T5420 is a professional-grade, battery-powered top-handle chainsaw designed for arborists and tree care professionals. It features a brushless motor, advanced lithium-ion battery technology, STIHL Quickstop® inertia chain brake, ergonomic design with anti-vibration system, tool-free chain tensioning, and electronic motor management. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Brushless electric motor, AP 500 S battery, guide bar and saw chain, chain tensioning wheel, front handguard with chain brake, throttle trigger lockout, battery charge indicator.

Feature	Description
Brushless Motor	High efficiency, low maintenance, increased power and runtime
STIHL Quickstop®	Inertia-activated chain brake for enhanced safety
Ergonomic Design	Anti-vibration system, lightweight construction
Tool-Free Chain Tensioning	Easy adjustment via side-mounted wheel
Electronic Management	Protects against overload, overheating, and deep discharge
Battery Indicator	LED display on battery shows charge status
Oilomatic® Chain	Automatic chain lubrication system
Throttle Trigger Lockout	Prevents accidental acceleration
Chain Catcher	Reduces risk in case of chain breakage
Compatible Batteries	AP 300 S, AP 500 S (included)

Assembly & Preparation

Unpack and inspect all contents. Ensure you have personal protective equipment (PPE).

1. Attach Guide Bar and Chain: Place bar onto sprocket, fit chain into bar groove, ensure cutting teeth face forward.
2. Tension Chain: Turn tensioning wheel clockwise until chain fits snugly against bar (can be lifted slightly by hand).
3. Install Battery: Insert AP 500 S battery into battery compartment until it clicks.
4. Fill Chain Oil: Use STIHL biodegradable chain oil; fill reservoir to marked level.

WARNING! Always wear certified safety gear: helmet, eye protection, hearing protection, gloves, chainsaw chaps, and sturdy boots.

First-Time Operation

Fully charge battery before first use. Perform safety check.

1. Power On: Press and hold the trigger lockout, then squeeze throttle trigger.
2. Test Chain Brake: With saw off, pull front handguard forward to engage brake; it should click and lock.
3. Check Oil Flow: Run saw at high speed over light-colored surface; look for oil splatter.
4. Practice Cutting: Start with small branches to familiarize yourself with tool balance and response.

CAUTION! Never operate with damaged or loose parts. Keep bystanders at least 15 feet away.

Specifications

• Power Source: STIHL AP 500 S Lithium-Ion Battery (36V).
• Guide Bar Length: 14 inches (35 cm) standard.
• Chain Pitch: 1/4" P (Picco Micro).
• Weight (without battery): 6.6 lbs (3.0 kg).
• Sound Power Level: 94 dB(A).
• Vibration Levels: Left/Right handle: 2.5/3.0 m/s².
• Oil Tank Capacity: 5.1 fl oz (150 ml).
• Recommended Battery: AP 500 S (500 Wh).
• Charger: AL 500 (standard) or AL 600 (fast charger).

Controls and Functions

Main Controls: Throttle trigger with lockout, front handguard/chain brake, chain tensioning wheel, battery release button, oil filler cap.

Indicator Lights: Battery charge indicator (LEDs: green=high, yellow=medium, red=low, flashing=critical).

Chain Brake: Manual activation via handguard; inertia activation via kickback. Chain Tensioning: Side wheel for quick adjustment. Oil Pump: Automatic; adjustable via screw near oil cap (factory set).

Battery & Charging

Use only STIHL AP series batteries and AL series chargers.

1. Charging: Insert battery into charger; connect to 120V outlet. LED indicates status (red=charging, green=complete).
2. Runtime: Approx. 45-60 minutes of continuous cutting with AP 500 S under normal load.
3. Storage: Store battery at 30-80% charge in cool, dry place (40-80°F / 5-25°C).
4. Transport: Protect terminals; do not carry loose in pocket with metal objects.

Tip: Have a spare charged battery for extended work sessions.

Cutting Techniques

Designed for pruning, limbing, and light felling.

1. Secure Workpiece: Ensure branch or log is stable and won't shift.
2. Plan Escape Route: Always have clear path away from falling material.
3. Use Correct Grip: Thumb wrapped around handle; maintain firm two-handed control.
4. Let Saw Do Work: Apply light pressure; avoid forcing or bending chain.
5. Bucking: Support log evenly; cut from top down, avoiding ground contact.
6. Limbing: Stand uphill; cut branches from opposite side of trunk.
7. Kickback Awareness: Keep nose of bar away from obstructions; use reduced-kickback chain.

WARNING! Never cut above shoulder height. Do not operate on ladders or unstable surfaces.

Maintenance Schedule

Daily: Clean air vents, check chain tension and sharpness, inspect bar for wear, top up chain oil. Weekly: Clean entire saw, check all fasteners, inspect sprocket tip. Monthly: Check brake function, inspect battery contacts, clean oil tank screen. As Needed: Sharpen or replace chain, replace guide bar, replace sprocket.

Storage & Transport

Store in dry, locked location out of reach of children. Remove battery for extended storage. Transport with chain guard installed and battery removed.

CAUTION! Do not store in damp or extreme temperatures. Always transport in approved case.

Regulatory Information

Complies with ANSI B175.1 and EPA regulations. Contains electrical equipment that may produce electromagnetic interference. STIHL and the STIHL logo are registered trademarks of Andreas Stihl AG & Co. KG. Battery and charger carry limited warranty; see separate warranty statement. For technical support, visit www.stihlusa.com or contact 1-800-467-8445.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Saw won't start	Battery empty/defective, lockout engaged	Charge or replace battery; ensure throttle lockout is depressed.
Chain doesn't move	Chain brake engaged, chain jammed	Pull handguard back to disengage brake; clear obstruction.
Poor cutting performance	Dull chain, low chain oil, loose chain	Sharpen or replace chain; refill oil; adjust tension.
Excessive vibration	Loose parts, damaged bar, unbalanced chain	Tighten all fasteners; inspect/replace bar and chain.
Battery not charging	Faulty charger, dirty contacts, temperature	Try different outlet/charger; clean terminals; allow battery to reach room temp.

Reset: Remove battery for 60 seconds to reset electronic system.

Service: Authorized STIHL dealers only. 1-800-467-8445; www.stihlusa.com