Gas-powered weed wacker operates on the suitable fuel with the engine provided. This means o cords and batteries. Thus, a gas-powered weed eater is generally used for maintaining the large yard where you need not worry about the length of the cord or charging of the battery. However, they do have some disadvantages, such as high emissions. But this matter is also resolved by the manufacturers of the best weed eater. On the other hand, battery-powered weed eater generally operates on the lithium-ion batteries provided along with the machine. Well, there is also the advantage of using this kind of weed eater as there are no cords at all. Moreover, you should go for battery-powered weed eater if you are having a small to a medium yard or if you don't want to mess with the fuel consumption, etc. They also cost less and are usually lightweight.