With the recent website migration, some files have been moved around. This post is meant to preserve some historic manuals and documentation to share with the community. Feel free to add additional manuals if you wish.
Or not! Sorry to rant-- I've had a very good experience with the E5000 so far, and I think it will serve me very well for many years to come. I got the right bike-- though I have had and will have others-- so I'm really not seriously complaining.
However, decoding Shimano's documentation and trying to figure out something that should be simple, like, "Can I upgrade my battery?" or "Can I mount a more powerful motor later when I get more old and feeble?" takes hours. It seems like there are dozens of manuals and compatibility charts, and none of them are set up to answer a question that someone is likely to actually have. I've never seen so much verbiage and so many diagrams that convey so little useful information. The strangest thing is that the manuals aren't cryptic or opaque, either. You can see and understand how they're structured; they do make sense, but it's still incredibly hard to find the information you need. I have no sensible explanation for it.
FWIW, in my case, the answer was: No to both. My bike can never have a different battery or motor. It literally took me two years, on and off, of searching both Shimano's documentation and various posts on this and other forums to figure that out. (This is unique to the 5000 and my bike's battery mount-- other motor mounts are do allow for upgraded motors.) I only mention this here in case anyone else has a similar dilemma. On the plus side, the motor will probably outlive me, as long as my heirs can find exactly the right model of battery to replace it when the time comes.