Most of the time a short run time is caused by old or worn out batteries. Most electric scooters and bikes should have around 20-45 minutes of run time depending upon the size of the batteries it has. This normal run time will be considerably less if the scooter or bike is used in a hilly area or on sand or loose dirt. Other causes of low run time are low air pressure in the tires or dragging brake shoes or pads. Most of time it is from old or worn out batteries though.