Battery electric motorcycle (BEM) 48V
48V powertrain in motorcycles used as a pure electric drive
The 48V powertrain in motorcycles is not used as a hybrid propulsion concept but as a pure electric drive as a 48V battery-electric motorcycle. The main motivation is efficient to drive dynamics by the high torque electric motor and weight reduction. The battery-electric motorcycle (BEM) 48V is often called as well E-motorbike and part of the high power light electric vehicles (LEV) with 5 to 30+ kW peak power.
For the 48V battery system, there is today mainly the fix mounted, non-exchangeable battery, but up to four stacks, exchangeable batteries are coming in the market too with a corresponding battery-swapping infrastructure, e.g. eMaaS (energy and mobility as a service). Independent of the number of batteries, each battery does have a battery management system (BMS) with an integrated battery disconnect switch (BDS). The BMS including the BDS concept is the same as for MHEV, shown on the application page battery management system (BMS) 48V.
For the 48V main inverter, there are primarily two motor types used in the market, depending on the speed and torque requirement. One is the BLDC (BrushLess DC motors) and the other is PMSM (PerManent Synchronous Motor), both are 3 phase for 5 to 30 kW peak power. The BLDC is the same type as we do have in mild hybrid electric vehicles (MHEV) in the belt-driven integrated starter generator (BiSG) 48V. The BLDC/ PMSM is the same concept as we do have it in the MHEV crankshaft-mounted integrated starter generator (CiSG) 48V. For higher power concepts like 60 to 96V systems are in discussions.
As in the mild-hybrid electric vehicles (MHEV), the only generator is on 48V. To continuously supply the remaining 12V network with energy, a DC/DC converter in buck-mode (step down) from 48V down to 12V is mandatory. The concept is the same for the power conversion DC/DC 48V/12V converter, but for lower power requirement 100 to 500 W, it is a non-isolated simple synchronous buck converter.
Today, there is no auxiliary loads in the E-motorbike. Only in some cases, the battery cooling compressor system is in a discussion on 48V in the 3 wheel segment.