48volt Power Supply Electric Scooter Power Fades....?

Electric scooter power fades....? - 48volt power supply

I have a scooter 48Volt, simply replace the charger from the crowd and the controller. Cells show that they took 48Volt. But if I download and turn it on, turn off at once, even just trying to off the gas. The lights show, which is the power and the battery just fade away after switching on the camera. During the loading process on the sample loading control. So it seems that they charge but was reserving battery for starting, it is something that seems wrong.