The guys at Cordless Renovations have come out with a New Battery-Powered Trailing-Car that you can easily install into a box-car, gondola, coal hopper, or tender. Here's a link to their website: http://cordlessrenovations.com/store/product_info.php?products_id=345 Here's the picture of the C-10L Lithium-Ion version: http://cordlessrenovations.com/store/popup_image.php?pID=345