Service manual

DCB, DCFCB and DCFCTB Models
44
Theory of Operation
Circuit Description
The charger implements a three-stage charging algorithm. The three stages are trickle
charge, bulk charge, and float charge. The stages operate as follows.
The charger supplies a steady 2 Amp current to the battery until the battery voltage
reaches a predetermined threshold value. The purpose behind trickle charging is to
prevent a potentially hazardous condition caused by continuously pumping bulk
charge current into a damaged battery. Too heavy a charge when the battery is in this
severely discharged state can cause gassing which is corrosive, explosive and
shortens the life of the battery.
Bulk Charge
The charger supplies as much current as the transformer can supply, limited to
4 Amps, during the bulk charge. The bulk charge starts as the battery voltage rises