Batteries are fine for small portable machines.
In fact more and more things are being made to run on batteries like electric drills, and cars. The big problem with batteries is that they run out at the most inconvenient times. They only strore a bit of energy so they can only supply electricity for a short time. Electric vehicles like milk floats carry huge heavy batteries filled with strong sulphuric acid, they can only go for a few hours at a rather slow speed before they need charging up. This sort of weight and short life means that batteries are not very useful for things like washing machines, which are heavy enough without extra for batteries.