The Skywalker 40A V2 is a brushless electronic speed controller (ESC) designed for use in electric model aircraft (fixed-wing) using 3-4S LiPo batteries. It belongs to Hobbywing’s “Skywalker V2” series, which features improved processing, programming flexibility, and protections compared to earlier versions.

This ESC is well-suited for mid-sized electric planes where a 40 A continuous current rating is adequate, and where you want advanced features like “search mode”, brake/reverse programming, and active freewheeling for better throttle response.

Features :

• 32-bit ARM M0 microprocessor running up to 96 MHz. This provides more processing power for smoother throttle response and advanced control. 
• DEO (“Driving Efficiency Optimization”) technology / Active Freewheeling: This helps improve throttle responsiveness, reduce heat generated by the ESC, and increase flight time / efficiency. 
• Brake & Reverse modes: The V2 series offers programmable brake, including “Reverse Brake” and “Linear Reverse” mode, which are useful in airplane/fixed-wing applications where you might want to simulate reverse thrust or slow down quickly on landing. 
• Search Mode: This is a neat feature where the motor pulses (beeps) enabling you to locate the aircraft if it lands or gets stuck in vegetation or out of sight. Also helps in alerting battery is still connected and idle.
• Multiple protection functions: The ESC includes protection for abnormal input voltage, throttle-signal loss (fail safe), low voltage cutoff, over-current, thermal overload, etc. These protections help prolong the life of the ESC and the aircraft’s electronics.
• Programmable parameters: Via the transmitter throttle stick sequence or via an LED Program Box (sold separately) you can adjust settings such as brake type/force, LiPo cell count/disconnect voltage, startup mode, timing, active freewheeling ON/OFF, etc. 
• Lightweight and compact (~36 g) with dimensions suitable for many electric plane installations.

Specifications :

• Continuous current: 40 A. 
• Peak (burst) current: 60 A (typically for short periods, e.g., 10 s). 
• Input voltage: 3-4S LiPo (roughly 11.1V to 14.8V nominal). 
• BEC (Battery Elimination Circuit) output: 5 V @ 5 A, switch-mode. 
• Physical size: approx 60 × 25 × 8 mm (L×W×H). 
• Weight: approx 36 g. 
• Supported maximum motor speed: “up to 300,000 RPM (2-pole motor)” in the V2 series. 

Applications :

This ESC is optimized for electric model airplanes (fixed wing) using 3-4 cell LiPo packs. Typical suitable motor sizes would be small to medium sized brushless motors, perhaps in the 2200–3200 kV class (depending on your prop and voltage) or whatever fits the 40 A continuous rating.

It works especially well when you want good throttle feel (for aerobatics or sport flying), and need features such as brake for landing, or reverse if your model supports it (e.g., scale warbirds with prop-reverse).

Because of its moderate size, weight (~36 g) and sensible current rating, it’s a good match for many hobbyist builds where you don’t need a massive 100 A ESC but still want reliable performance.

Installation and Setup Tips :

• Before flight, calibrate your ESC: many users recommend calibrating the throttle range (i.e., set transmitter throttle stick to max, power on ESC, wait until it beeps, then bring throttle to zero). Reference user manual for correct procedure. 
• Ensure adequate cooling: even though the V2 series is more efficient, at 40 A continuous you still produce heat. Mount the ESC with airflow or on a surface with thermal contact (if permissible by your model).
• Choose wiring that supports the current: Make sure battery leads, motor wires, and connectors are sized appropriately to avoid voltage drop or heating.
• Set your LiPo cell count properly in programming: Since this ESC uses LiPo packs, set the low voltage cutoff (or leave default) so battery is not over-discharged.
• Use the correct propeller: Excessive load (too big a prop) could push the ESC past its 40 A continuous rating — monitor current and temperature especially on first flights.
• Use the brake/reverse carefully: For fixed wing, enable brake if desired (e.g., to stop prop quickly on landing). For reverse, ensure your model and prop setup support it safely (reverse thrust may stress motor mount or airframe).
• Activate Search Mode if you want: This is helpful if your model might go out of sight/hidden — you can program in the mode so the motor pulses/beeps to help you find it.

Note :

• Voltage range is limited to 3-4S LiPo: If you plan to use higher voltages (5S, 6S, etc), this ESC cannot support that.
• Continuous current 40 A: For heavier models or higher power motors propeller combos you might need higher rated ESC (50A, 60A, etc).
• Firmware upgrade not supported: The manual states the firmware upgrade is “Not Supported” for many Skywalker V2 models.
• Requires proper installation and cooling: As with all ESCs, insufficient cooling or overload can lead to thermal shutdown or failure—users should still monitor conditions.