A321 Pilot reported receiving an ECAM non-normal ELEC BCL2 FAULT during cruise prior to the ETOPS entry point. Consultation with maintenance provided no remedy and a diversion was made.

Narrative

Departed ZZZ at XA:30Z for ZZZ1. Flight operated normal until approximately XB:00Z had an ECAM non-normal (Battery Charge Limiter) fault. Applied strategy and concluded we need to contact Dispatch/Maintenance due to APU battery start not available. Aircraft not yet in ETOPS at this time. After establishing SATCOM contact with Dispatch and Maintenance discussed options and jointly decided on divert to ZZZ2. I requested priority handling at this time due to landing at airport other than Dispatched and anticipated overweight landing. The Flight Attendants (F/As) were briefed next on precautionary landing and then a detailed explanation PA to the passengers. Next we completed duties related to divert including reviewing QRH Non-Routine Landing Considerations and Overweight Landing. Pilot Flying (PF) was the First Officer (FO) for uneventful descent; approach and landing. First Officer did an amazing job as PF and other duties. After landing ZZZ2 Tower gave us a discreet frequency to use and asked intentions. Everything was normal including brake temps; but I decided to use the Airport Rescue and Firefighting (ARFF) resource to check brake areas. Shortly after normal taxi to the gate and multiple logbook write-ups.