If the BX60 detects a sulfated battery (old battery that won’t hold charge), it will pulse high-frequency voltage to break down lead-sulfate crystals. This happens automatically during the first 10 minutes of charging. The Fault LED may flash during this process—do not interrupt it unless it flashes for more than 30 minutes.
The Bradex BX60 uses an to show the charging status: bradex bx60 battery charger instructions best