Repeating what I just posted in another thread:
If you have a friend who has technical expertise and equipment, you might take a look at
http://forums.segwaychat.com/showthr...474#post220474
That sounds strikingly similar to what you experienced.
That is a single-occurrance, so no guarantees. But it could be worth a shot, if you understand the technical situation and real caution that is required.
I have a "theory" as to why this battery condition can happen after a Segway has been plugged in continuously for many months (which is the recommended thing to do) which is apparently your situation, also.