We have a few options for electric camper van conversion pack sizes. The bigger the battery pack; the further range you will get. The smaller range is a single box that sits where the engine used to sit. The bigger range is that same first box with an extra box underneath the vehicle where the chassis rails are.
Having all of the batteries external is good for the interior reasons I mentioned, before no compromise to your interior, or to any of-the-shelf interior that you may want. If we are converting the camper van interiors for you as well, we can give you all the options without worrying about having to work around battery packs but it’s also much safer. There is no high voltage inside the cab. Much safer for families, much safer for kids to have all of that outside of the vehicle.