NOVELTY - The motor is coupled to the battery. the generator converts fuel to electrical power and recharges battery. The off-board station includes a mean for receiving electrical power from the mobile vehicle power system and output means to provide a portion of electrical power for use off-board the power system.    USE - On-board fuel cell system for e.g. trains, marine vessels, automobiles, motorcycles, motorbikes, etc.    ADVANTAGE - The off-board station and the vehicle can be quickly and easily interconnected . the electricity exchange system can be installed at numerous locations allowing a mobile vehicle operator to purchase or sell electricity. The system does not require excessively frequent stops and interruptive recharging from off-board sources, can accommodate motor vehicle surge and range demands, and can generate power for off-board consumption.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a power exchange system comprising an off-board station for use with a mobile vehicle power system, electrical connection means to receive electrical power generated by the generator of the power system and communication means for communicating information regarding at least one of the operation of the on-board generator and parameters regarding the condition of the off-board station to another location;    (2) a power exchange system comprising 1st power system comprising rechargeable battery, generator, fuel storage means and coupling men as, and 2nd power system comprising rechargeable battery and means to receive electrical power from 1st power system to recharge 2nd battery;    (3) an interface electricity exchange system for exchanging electricity with an electric powered vehicle comprising an interface housing, a monitoring stage, a calculation stage, user authorization receiving means and storage for recording exchange of electricity or fuel between the vehicle and housing; and    (4) a process for exchanging electricity between interface electricity exchange system and electric powered vehicle.    DESCRIPTION OF DRAWING(S) - The diagram shows an electricity exchange system for supplying or receiving electricity from a mobile vehicle power system.    Electricity exchange system (100)    Electrical leads (108,110)    Interface exchange facility (102)    Interface housing (104)    Communication link (111)    Mechanical switches (112)