OEM Electric Bicycles: 250W/500W from China Manufacturers

An OEM electric bicycle is a pedal-assisted bicycle built to a buyer’s frame, motor, and battery specification, then assembled and branded at a China factory. It combines a mechanical bicycle platform — often the same alloy frames used for a folding bicycle — with a battery-motor drive system, so sourcing it successfully means controlling both frame quality and electrical safety. Most buyers order 50–200 units for a first run, with 45–70 day lead times depending on battery cell availability and custom paint or decal work. Voltage class, motor wattage, and speed limit must match the target market from the start — retrofitting compliance after tooling is expensive.

Typical Specifications to Confirm Before Ordering

Before placing a purchase order, lock the spec sheet in writing. Confirm motor rated power (250W for EU EPAC, 500W for US Class 2), motor type (rear hub or mid-drive such as Bafang M200/M400), battery voltage and capacity (36V 10.4Ah or 48V 13Ah), cell brand (Samsung or LG), controller current limit, display type, charger safety approvals, frame alloy (6061-T6 aluminum), brake type (hydraulic disc), and wheel size. Also confirm that the supplier’s EN 15194, CE, UN 38.3, and RoHS documentation covers the exact SKU you will import, not just a generic platform.

Common Pitfall: Battery Cell Substitution and a Weak BMS

The most expensive failure in custom e-bike sourcing is an undocumented battery change. Some factories quote Samsung or LG cells, then build production units with unbranded cells that lose capacity within 200 cycles and lack thermal runaway protection. Demand a cell declaration, cycle-test report (≥80% retention after 500 cycles), and BMS test data for overcharge, overdischarge, overcurrent, and balancing. This crosses into vehicle-grade electronics compliance territory, so treat weak documentation as a red flag and switch suppliers if the factory refuses an independent cell inspection.

Concrete Use Case: EU E-Mobility Startup Launch

A typical buyer is a Berlin-based e-mobility startup that needs 100 private-label 250W city e-bikes for a subscription fleet. They require EN 15194 compliance for EU street legality, a removable 36V battery for apartment charging, and branding on the frame and display. They source through Tianjin and Guangdong factories, run a factory audit to verify frame weld and battery documentation, and book a pre-shipment inspection before the container leaves the port.

Recommended Next Steps

Start by requesting a physical sample, not just photos. Test ride the sample for motor assist behavior, brake performance, and battery range, then open the battery case to verify cell markings and BMS layout. Cross-check the supplier’s EN 15194 and UN 38.3 certificates against your target market, and use the tariff calculator to estimate landed cost before you commit to an order. If you need help vetting battery documentation, read our guide on how to verify battery certification in China.

Controller, Display, and Charger Specifications

The controller is the brain that links pedal-assist sensors, throttle (where legal), motor, and battery. Confirm continuous current rating (e.g., 15A or 20A), IP rating (IP65 minimum for outdoor use), and whether the firmware supports speed-limit profiles for EU versus US markets. The display should show speed, battery state of charge, and assist level; some buyers add Bluetooth or NFC modules for fleet tracking. The charger must carry CE or UL markings and use a proper CC/CV charging curve with over-temperature protection. A 36V 10.4Ah pack typically charges in 4–6 hours with a 2A charger. Request the charger’s safety certificate separately — factories sometimes ship a compliant charger for samples and a generic one for bulk.

Shipping and Packaging for Complete E-Bikes

Complete e-bikes are usually shipped 85% assembled in reinforced cartons, with the front wheel, pedals, and handlebar detached. A standard carton for a 26-inch or 27.5-inch e-bike measures roughly 145 × 25 × 80 cm and occupies about 0.29 m³. A 40-foot high-cube container fits roughly 220–250 units depending on carton size and packing pattern. If batteries are shipped separately due to forwarder restrictions, budget extra for hazardous-goods packaging, UN 38.3 labels, and a separate customs entry. Sea freight to EU ports typically takes 28–35 days from Shenzhen or Tianjin, plus 3–7 days for customs clearance and inland haulage.

Red Flag: A Factory That Cannot Explain Recalls

Ask whether the factory has ever had an e-bike or battery recall in the EU or US. A supplier that deflects the question or claims it has never had any problem is less useful than one that can explain a past issue and the engineering change that fixed it. This is especially important when sourcing through trading companies that do not own the assembly line. We map the actual factory before placing an order so you know who is building your bikes.

EN 15194 Compliance: The EU EPAC Standard for Wholesale E-Bikes

EN 15194:2017 is the mandatory standard for electrically power-assisted cycles (EPAC) in the European Union. When sourcing from an electric bicycle manufacturer in China, verifying compliance is paramount. Key requirements: motor rated power must not exceed 250W, motor assistance must cut off when the rider stops pedaling or reaches 25 km/h, and the battery system must meet rigorous electrical safety requirements. A CE-marked e-bike without EN 15194 compliance documentation is not legally an EPAC — it falls under L-category motorcycle type approval instead, requiring registration, insurance, and a driving license, severely limiting your market for wholesale e-bikes.

EN 15194 compliance requires testing at an accredited notified body and costs approximately €1,500–3,000 per custom electric bike model. Leading Chinese factories supplying EU importers should already have this certification for their base frame and motor combinations. Our audit service verifies that the certification covers your specific battery-motor combination — changing from a 10Ah to 15Ah battery may void the existing type certificate and require re-testing, impacting your e-bike sourcing timeline.

Battery Cell Grade and BMS Protection for Custom Electric Bikes

The lithium-ion battery pack is the highest-risk component for e-mobility products, dictating the longevity and safety of your private label e-bikes. Samsung 21700 50E or LG M50T cells (3.6V, 5Ah) are the reference tier for branded wholesale buyers. In contrast, generic cells often lose 25–35% capacity within 200 cycles and generate inconsistent pedal-assist range claims. Always require your electric bike supplier to declare their cell provider and supply a cell spec sheet with cycle test data (capacity retention at 80% after 500 cycles minimum).

BMS (Battery Management System) protection functions to verify: overcharge protection (cuts at 4.2V per cell ±0.05V), overdischarge protection (cuts at 2.75–3.0V per cell), overcurrent protection (triggers at <150% of rated discharge current), and cell balancing during charging. UN 38.3 certification is required for air freight of lithium battery packs — without it, most air freight forwarders will not accept the shipment. Our inspection service can verify BMS protection thresholds and cell balancing behavior on production samples. See our automotive electronics industry page for more on vehicle-grade electronics certification requirements.