Low Speed Electric Motorcycle -Newest Development in eMobility

Every now and then Bicle invites a mobility industry expert to write a column. In his second article, Liu Yang, Vice Director of LEV Division of Phylion Battery, talks about how to define the Low Speed Electric Motorcycle and explains about the technical requirements of an e-scooter.

E-Scooter or E-Motorcycle, as a common means of transportation in China, has a history of 20 years. Over the past year, more than 30 million electric bicycles have been sold in China, which is expected to continue to grow this year. South Asia and South-East Asia, represented by India, also have recently witnessed a surge in sales of E-Scooter and E-Motorcycle along with government subsidies for new energy. But these products have not been popularized in the European market for many years. However, with the trend of environmental protection and some fundamental obstacles to the popularization of electric vehicles still not well solved, E-Scooter or E-Motorcycle may be a new choice for new energy vehicles in Europe in the next 5-10 years.

How to define e-scooter and e-motorcycle?

In terms of speed, it is defined as E-Scooter or Low-speed E-Motorcycle under the speed of 45Km/h, and high-speed e-motorcycle which exceeding the speed of 45Km/h. In addition, unlike E-bike and traditional bicycles, E-scooter and E-Motorcycle tend to be more like light motorcycles and motorcycles in terms of shape.

For the time being, e-scooter (Low-speed e-motorcycles) may be a good choice for the European market.

High speed e-motorcycle has very high requirements for the whole system, and there is no mature solution at present. While e-scooter and low speed e-motor cycle seems to be a more feasible solutions.

Technical requirements for low speed e-motorcycle batteries

Since the power is fully supplied by electricity, so even for e-scooter and low speed e-motorcycle, have higher technical requirements than e-bike which does not exceed the speed of 25Km per hour.

Safety, heat management, current equalize and cycle life of batteries are key indicators for the e-scooter batteries.

Safety: The choice of appropriate cathode material determines the safety of the battery. For lithium batteries, using LMO as cathode material is a good choice. Other design points including less cells in parallel is better; thermal management; flame retardant material; anti-fire spread; water resistance; pressure release system; anti-vibration; connection between cells, connectors; resistance of cables, etc.

Thermal management: Good design of temperature control for BMS ensures the safe use of batteries. And reasonable pack structure will contribute to the heat dissipation of batteries as well.

Thermal management simulation: Phylion’s 60V40Ah battery pack with prismatic cell.

A: close fitting between cells

B: air between cells

C: heat dissipation plate between cells

D: clad plate between cells

Current equalize: The current equalize refers to the active or passive way to make the voltage of all battery cells in the pack uniform, in order to maximize the efficiency of the battery.

Cycle life: The cycle life of battery is also very important for the vehicle. The cycle life of the battery is determined by various factors including cathode material of the cell, depth of discharge, C-rate performance, efficiency of the drive system, etc.