cool idea but may result in space problems as none of the current cabby's come with a provision of storing a battery inside, can keep the battery outside though, but it might look odd to some.
I guess its a very very old product, when power consumptions were very low....my conclusion is coz the software supports, win95 till win98, no xp or vista....even the cabinets used are the old ones which used to sell like 7-8 years ago....