To manage a fleet of vehicles efficiently, data is obtained concerning vehicle condition; some of this data is recorded in a data packet format on a vehicle and transmitted by radio from the vehicles to a base station, and under some circumstances, transmitted by the internet to a central data station where it is used to determine what should be done with the vehicles, such as for example to determine if the battery of a vehicle must be charged. The data may be transmitted from one vehicle to another vehicle before reaching the base station or the central data station. The data packets can indicate the vehicle to which the data applies, if the battery needs to be charged or replaced and can establish a priority schedule for the charging or replacement of the battery.