Convert a Fuel Motorcycle to Electric - 15cc to 150cc Conversion Guide

Converting a petrol (ICE) motorcycle or scooter to electric means removing the engine, fuel tank and exhaust, then fitting a traction motor（牵引电机）, a battery pack（电池包）, a controller（控制器） and an onboard charger（车载充电器）. This guide covers the full 15cc-150cc range - mopeds, underbones and small street bikes - with a parts list（配件清单） and selection advice（选型建议） for each displacement band, plus the drivetrain options that decide how the motor drives the wheel.

Fig.1 - How an ICE-to-EV conversion is wired

Battery to Controller to Motor to the rear wheel. The throttle talks to the controller; the BMS lives inside the battery; the charger refills the pack; a DC-DC feeds the 12V lights.

Fig.1 Electric drivetrain - what replaces the engine in a 15-150cc conversion.

Three displacement bands at a glance

Figures are engineering starting points, not guarantees. Final selection depends on donor bike weight, rider load, terrain (hills), and your local e-motorcycle class rules. Talk to our Pakistan desk before committing a BOM.

Band A - 15-49cc (mopeds and mini scooters)

Motor（电机）

Use a 48V BLDC. For the simplest build, drop a rear hub motor (800-1200W) into the wheel - no fabrication, the frame stays original. If you want more torque for slopes, use a swingarm-mounted BLDC (1000-1500W) coupled by chain to the original rear sprocket. YBNIU stocks both: see the traction motor and 48-72V controller.

Battery（电池）

A 48V 20-30Ah LiFePO4 pack (1.0-1.4 kWh) or an NMC 48V 24Ah pack. Mount it under the seat or in the empty fuel-tank space. It must include a 16S BMS rated at 40A continuous. Build from grade-A LiFePO4 cells or use a ready 48V pack as a base.

Controller（控制器）

A 48V sine-wave (FOC) controller, 30-45A, regen-capable and waterproof. Match the phase and hall signals to the motor - order the motor and controller as a matched set so they speak the same protocol on first power-up.

Drivetrain / transmission（传动系统）

With a hub motor there is no transmission - it drives the wheel directly. With a chain motor, remove the engine, bolt or weld a motor plate to the swingarm, and align the motor sprocket to the original rear sprocket; keep the existing chain.

Supporting parts and BOM

Selection advice: keep the original brakes for band A; top speed 40-50 km/h and 40-60 km range make this the ideal first conversion and last-mile vehicle. Verify the wheel hub strength before lacing a hub motor.

Band B - 50-90cc (underbones and scooters)

Motor（电机）

A 60V BLDC 1500-3000W. A swingarm chain-drive motor is recommended for torque and hill-climbing; a 2000W rear hub is viable on wide-rear scooters. See traction motor.

Battery（电池）

60V 30-45Ah LiFePO4 (1.8-2.7 kWh) or NMC 60V 40Ah, with a 20S BMS rated 80A. Mount under the seat and footboard.

Controller（控制器）

60V sine-wave controller, 50-80A, regen and field-weakening for top speed, waterproof and programmable. Match to the motor as a set.

Drivetrain / transmission（传动系统）

Chain to the rear sprocket (keep the wheel), or delete the CVT belt and run a belt from the motor pulley. For step-through scooters a hub motor is the easier route.

Supporting parts and BOM

Selection advice: top speed 50-65 km/h, range 55-80 km. Upgrade the brakes and fit a torque arm if you use a hub motor; verify swingarm mounting for a chain motor.

Band C - 100-150cc (street bikes)

Motor（电机）

A 72V BLDC 3000-5000W (some builds run a 72V 5kW unit). A swingarm chain-drive is strongly recommended; a 5000W hub is possible but heavy and stresses the front fork. See traction motor.

Battery（电池）

72V 40-60Ah LiFePO4 (2.9-4.3 kWh) or NMC 72V 50Ah, with a 24S BMS rated 120A. Mount across the frame and in panniers; battery weight becomes a handling factor at this size.

Controller（控制器）

72V sine-wave controller, 80-120A, regen, programmable, waterproof, with a pre-charge circuit to protect the contacts. Match as a set with the motor and cluster.

Drivetrain / transmission（传动系统）

Chain to the rear sprocket; the motor spins faster than the wheel, so choose the sprocket ratio for your target speed. Keep or upgrade the chain and sprockets (428/520 pitch). A reduction stage is sometimes needed between motor and wheel.

Supporting parts and BOM

Selection advice: top speed 65-90 km/h, range 70-110 km. Brakes and frame are critical - fit hydraulic discs, consider suspension upgrade, and tune regen for battery life. At this power the bike may need registration as an e-motorcycle under local rules.

Drivetrain and coupling options

Pakistan import notes for conversion kits

Motors (HS 8501.32), controllers (HS 8542.31) and chargers / DC-DC (HS 8504.40) qualify for Pakistan's EV-specific 1% duty window for e-motorcycle CKD, valid until 30 June 2027 - versus 15% general duty. Battery cells (HS 8507.60) are assessed separately; confirm the exact heading with your clearing agent per consignment. We cite the codes on every invoice, packing list and datasheet. Ship to Karachi Port / Port Qasim; our Pakistan desk sizes the BOM and handles the paperwork.

Safety and legal notes

• Mount the battery in a vented, secured enclosure - never loose in a bag.
• Fuse the main positive within 150 mm of the pack and add a contactor you can cut from the key switch.
• Upgrade brakes before adding power - regen is not a substitute for mechanical braking.
• Check your local e-motorcycle class rules; 100-150cc-class conversions may require registration and type approval.

Buyer questions

Local support and next step

改装知识体系（10 页分页版） → 排量分档改装指南（BOM） → Full EV parts checklist → EV Buyer's Guide → Pakistan Buyers Hub →