How an Electric Forklift Operates from Key Switch to Driving (A–Z Guide)

Electric forklifts are widely used in warehouses and factories thanks to their smooth operation, low operating cost, and environmental friendliness. However, many users still do not clearly understand how an electric forklift actually works internally, from turning the key to when the forklift starts moving.

This article explains the complete operating process of an electric forklift step by step, suitable for operators, technicians, and forklift dealers.

1. Turning the Key – Activating the Main Electrical System

When the ignition key is turned to the ON position:

DC power is supplied from the battery (lead-acid or lithium)
Power flows through:
- Main fuse
- Emergency stop switch
- Key switch
The main controller (ECU) is powered on

At this stage:

The display turns on
Battery level and system indicators appear
The forklift is ready, but not moving yet

2. Safety System Check Before Driving

Before allowing movement, the controller checks multiple safety conditions:

Seat switch detects an operator
Parking brake is released
Direction lever is in Neutral
No critical faults from:
- Motor
- Controller
- Accelerator or brake sensors

❗ If any condition is not met:

The forklift will not move
A fault code may appear
You may hear a relay click but the motor will not rotate

3. Brake Release – Electromagnetic Brake Operation

Most electric forklifts use an electromagnetic brake.

When stopped:

The brake is engaged
The motor shaft is locked
The forklift remains stationary, even on slopes

When the operator:

Releases the brake
Presses the accelerator

👉 The controller energizes the brake coil:

The brake releases
The motor shaft is unlocked

✔️ This design ensures safety:
Power loss = brake automatically engages

4. Pressing the Accelerator – Sending Control Signals

The accelerator pedal does not directly power the motor.

Instead:

A sensor (potentiometer or Hall sensor) sends a voltage signal
Example range: 0.8V – 4.2V
The signal represents desired speed

The controller calculates:

Current
Voltage
Motor speed
Travel direction (forward / reverse)

5. Controller Powers the Drive Motor

Once all conditions are met:

The controller uses IGBTs or MOSFETs
Converts DC power using PWM signals
Supplies controlled power to the traction motor

The motor:

Rotates
Transfers torque through the gearbox
Drives the wheels

🚜 The forklift starts moving smoothly without jerking.

6. Speed and Direction Control During Operation

While driving, the controller continuously monitors:

Motor current
Motor temperature
Battery voltage
Load conditions

When changing direction:

Speed is reduced first
The motor stops
Direction is safely reversed
Acceleration resumes

This protects:

The motor
Gearbox
Battery system

7. Releasing Accelerator or Braking – Stopping the Forklift

Releasing the accelerator:

Controller reduces PWM output
Motor slows down
Regenerative braking may occur

Pressing the brake:

Mechanical brake + electromagnetic brake engage
Motor power is cut
The forklift stops and is held securely

8. Turning the Key OFF – System Shutdown

When the key is turned OFF:

Controller loses power
Motor power is cut
Electromagnetic brake engages
The forklift enters a fully safe state

Electric Forklift Operating Process Summary

Turn key ON → system powered
Safety checks completed
Brake released
Accelerator signal sent
Controller powers motor
Forklift moves
Brake or release accelerator → stop
Key OFF → system shutdown

Frequently Asked Questions (Q&A)

Q: Why does the forklift power on but not move?
A: Possible causes include engaged brake, seat switch not activated, low battery, or controller fault.

Q: Does an electric forklift have a clutch like a diesel forklift?
A: No. Electric forklifts are fully electronically controlled.

Q: Will the forklift roll if power is lost?
A: No. The electromagnetic brake automatically engages.

Q: Why does an electric forklift feel weak?
A: Usually due to weak battery, overheating motor, or controller current limiting.

Q: Does an electric forklift need warm-up time?
A: No. It can operate immediately once powered on.