A319 rejected takeoff at low speed due to receipt of ECAM ELECT BCL (2) FAULT.

Narrative

As I aligned the aircraft on the runway; we accomplished the transfer of control and just as the First Officer set the thrust levers for 50% N1; we received an ECAM ELECT BCL (2) FAULT. The engines just began to accelerate when the First Officer brought the power back to idle; as I was getting ready to announce the reject. We transferred control back to me; canceled the takeoff with the tower and asked if we could hold our position momentarily on the runway. Tower approved but with traffic on about a 10 mile final; I elected to get clearance to taxi clear of the runway. On the taxiway; we reference the QRH and did not find any procedure other than in the supplemental ECAM book. I called Maintenance Control and they said to taxi back to the gate that he was not able to allow flight with the configuration. We taxied back; called Operations; Dispatch and Maintenance once at the gate. Contract Maintenance was able to reset and after refueling we dispatched again without incident. Although technically a rejected takeoff; our speed did not exceed five knots and forward movement on the runway did not exceed about 20 feet.