While reading the above comments I wonder why anyone would be intersted in just "repelling" mice. On our ranches we have numerous ranch equipment that is stored in our machine sheds, for sometimes months, other times for a week or more, and some equipment that is stored outside between uses. If we let them, mice will build nests in and on engines, is other places in and on the equipment, and in general create danger and problems of extra cleaning, etc.
I buy material (there are verious ones available) at our CoOp that we keep distributed in the shops, and in the engine compartments, etc., of our trucks, tractors, machinery, etc., when they are in storeage. By hanging tubes of mice blocks (the ones I use have holes designed for twine to tie to) in various places where mice can get to them, we almost never see any sign of mice. I suspect that the mice blocks probably contain Warfarin or similar. I don't know but I know that after we had mice problems many years ago, and decided to stop the problem, we never have any more mice now.