You can just use standard AA batteries in them; however I put some in mine and they ran down in no time at all. There is a Newton mains adapter which I'd like to get so that I can play with it without having to worry about the batteries as it's expensive to have to keep buying batteries for it, but I guess you'd never find the adapter either The machine only cost me £5 so it's not really worth spending large amounts of money to get an adapter, and I don't imagine it's easy to find on otherwise.