Battery charger requirements : Each battery charger furnished shall be self-regulating, solid-state silicon controlled full wave rectifier type designed for single operation with the batteries. Chargers shall be designed for automatic operation. The load design of each charger shall include provisions to actuate an alarm and automatically return the charger to single operation in the event of: charger malfunction or component failure; over or under voltage; loss of ac supply; loss of load. Each charger shall be provided I.th current limiting circuitry. All chargers shall be capable of stable operation as battery eliminators.