Charging current will be limited by the output of the charger
Your charger has a 50 watt limit when running on AC power and a 70 watt limit when running on DC power (seperate power supply)
50 watts for a 4s pack will limit charging current to 2.97 amps
70 watts for a 4s pack will limit charging current to 4.16 amps
50 watts for a 2s pack will be 5.95 amps
Cheers