It's good. The solar range extender is like a generator, which starts to generate electricity when the battery is almost dead, replenishes the battery in time and increases the cruising range. Because the cruising range of low-speed electric four-wheeled vehicles is still limited, it can not fully meet the daily travel needs of the public. If you want to increase its cruising range, you can install a range extender to increase its cruising range, increase its range of activities, meet the daily travel needs of the public, realize the freedom of traveling back and forth, and no longer struggle because of power failure in the middle.