What are the dimensions of the hydrogen water bottle? The hydrogen water bottle can be ordered separately from the generator. It comes in 2 sizes: 4L: 15x15x35cm (LxWxH)8L: 20x20x42.5cm (LxWxH) Can't find what you are looking for? Contact us here or phone your local tech support help centre. Related articles Who to contact when my generator's service light is on? Comments 0 comments Please sign in to leave a comment.