NOVELTY - The method involves assigning one rating among a set of ratings to a set of industrial vehicles (10), where the rating indicates an intensity level at which one of the industrial vehicles is operated. A parameter indicating present capability of a set of batteries is occasionally measured to supply power for each battery to produce a parameter measurement. One of the batteries is installed on the particular industrial vehicle in response to a relationship between the rating assigned to the particular industrial vehicle and the parameter measurement for the battery.    USE - Method for allocating a set of rechargeable and removable batteries to a set of industrial vehicles i.e. lift lorries.    ADVANTAGE - The method enables comparing level of electric current at ends of a battery cable to detect current leakage to the frame or other components of the industrial vehicle occurring if the insulation of the battery cable has cracks, so that difference in the electric current levels measured at the ends of the battery cable exceeding a predefined threshold causes an alert to be given to a vehicle operator or personnel at a battery charging station, thus automatically checking the integrity of the battery cable and providing an alert when significant deterioration is occurred. The method enables calculating present battery condition by a battery sensor module or a vehicle controller periodically during use on the industrial vehicle. The method enables notifying the vehicle operator that the battery capacity is diminished to a point when a present battery condition falls below predefined threshold, so that the operation of the industrial vehicle prolongs the operational period without replacing heavy batteries, thus minimizes the down time and prolonging the service work time.    DETAILED DESCRIPTION - The parameter is resistance and battery capacity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a vehicle fleet management system in which fleets of industrial vehicles communicate via a network with a central computer in a warehouse that is linked to a remote database to which other computers have access.    Industrial vehicles (10)    Warehouse (100)    Battery charging stations (101)    Communication system (102)    Charging equipment (103)