Aluminum alloy LiFePO4, Lithium iron battery Pedal assistant Brushless spoke motor 200/250W Max. Forward speed 25 km/h. General features are as follows. 1. High energy density, small size, light weight 2, Long life cycle, no memory effect, High C-Rate Discharge capability 3. Maintenance free, chemically stable 4. Environmental friendly, no heavy metal Lead pollution. 19KG.