What was found
THE GROUND REFUEL POWER, FUEL TANK FILL VALVE, AND BATTERY BUS SENSING CIRCUIT BREAKERS POPPED WHILE EN ROUTE FROM FCO TO EWR. THE BATTERY BUS OFF LIGHT ILLUMINATED AND THE FUEL FILL VALVES CLOSED. FUEL COULD NOT BE TRANSFERRED. THE AIRCRAFT WAS DIVERTED TO LGW WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE EMERGENCY DC POWER R2-24 CHARGER/BATTERY RELAY (ON PANEL INSTL - BATTERY) AT FAULT. THE R2-24 RELAY WAS REMOVED AND REPLACED. OPERATIONAL CHECKS WERE GOOD.