Question 1

How do I size a BLDC motor for my electric vehicle?

Accepted Answer

Start with vehicle gross weight, desired top speed and maximum gradient. For flat ground cruising, power (W) equals roughly vehicle weight (kg) times speed (m/s) times rolling resistance coefficient (typically 0.01-0.015) times 9.8. For hill climbing, add the grade component: weight times speed times sin(grade angle) times 9.8. A 500 kg neighborhood EV at 25 km/h on flat ground needs about 200-300W continuous, but climbing a 10% grade at the same speed requires 1200-1500W. Always size the motor for the peak load scenario, not just cruising.

Question 2

Do Shenghe BLDC motors support regenerative braking?

Accepted Answer

Yes. BLDC motors are inherently capable of regenerative braking — when the vehicle decelerates, the motor acts as a generator and feeds energy back to the battery. This requires a compatible controller with regen capability. Shenghe offers matched motor-controller packages for EV applications that include configurable regen braking strength, which typically recovers 8-15% of energy in stop-and-go urban driving.

Question 3

What battery voltage is best for low-speed EV BLDC motors?

Accepted Answer

48V is the most common choice for golf carts, neighborhood EVs and light utility vehicles under 1000W. It balances safety (below the 60V DC hazard threshold) with reasonable wire gauge and current levels. For higher-power vehicles above 1500W — such as e-rickshaws, loaded cargo trikes and larger NEVs — 72V reduces current draw and wiring losses. Shenghe stocks both 48V and 72V motor variants and can wind custom voltages for specific battery pack configurations.

Question 4

How much torque does a BLDC motor need for hill climbing?

Accepted Answer

A rough formula: wheel torque (Nm) = vehicle weight (kg) x 9.8 x tire radius (m) x sin(grade angle). For a 600 kg vehicle with 0.25 m tire radius on a 15% slope (8.5 degrees), the required wheel torque is about 220 Nm. With a 10:1 gear reduction, the motor needs 22 Nm peak torque. Shenghe EV-series motors with planetary gearboxes deliver peak torques from 15 Nm to over 100 Nm at the gearbox output, covering most low-speed EV hill-climbing requirements.

Parameter	Range
Voltage	DC 48V / 72V
Rated power	400 W — 3000 W
Peak power	Up to 2x rated for 60 seconds
Motor speed	2000 — 4500 RPM
Gear ratio	5:1 — 20:1 (planetary)
Output torque	10 Nm — 120 Nm (at gearbox)
Protection	IP54 / IP65
Feedback	Hall sensor (3-phase) + speed sensor

BLDC Motor For Electric Vehicles And E-Mobility.

What Makes Brushless Motors The Choice For Electric Vehicle Drives

Typical EV Motor Spec Range

Electric Vehicle Use Cases

EV-Specific Technical Details

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Motor For Your Electric Vehicle?