A Li-Mn battery is lightweight with 500-800 full cycles of effective life and is the best choice for an ebike application. Packs of 30, 40, 50 or more cylindrical 18650 cells are the best option because you have the ability to maintain them compared to polymer packs. They are also lighter than Li-FePO4 technology.
Each 3.7V cell is continuously monitored and protected from over-voltage, under-voltage and over-current as well as 10 or 13 series cells voltage balance to guarantee maximum pack life cycle.
The battery packs are manufactured under strict qualifications and are CE and RoHS stamped.